From robert.jarratt at ntlworld.com Sun May 1 01:14:29 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Sun, 1 May 2022 07:14:29 +0100 Subject: Repairing a VT240. In-Reply-To: References: Message-ID: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> > -----Original Message----- > From: cctalk On Behalf Of Chris Zach via > cctalk > Sent: 01 May 2022 02:57 > To: CCTalk mailing list > Subject: Repairing a VT240. > > So I'm clearing out projects on my bench. The latest is a Dec VT240 which did > not work. Has been dead for 20 years, the usual so I figured I would see if I > could get it to run. This is a quick summary of what I did in the hopes it can > help someone else out someday. > > First I got the service manual. It's full of good information. Then I opened it > up and checked out the power supply. 5 volts was fine, -12 was fine, +12 was > a bit off (10v) but I didn't have the unit under any load. > Putting a small load on 5 and 12 got me a solid +12v and 5.1v so all was good > there. > > Then I hooked it up to the board and fired it up. Voltages were still good > (nothing big shorted) and the VR201 would come up, display a screen filling > up with scan lines 3 times, then go black with nothing. Keyboard had WAIT lit > and didn't work. So something was wrong. > > Looking through the manual I saw that this thing is nuts: It has a full > pdp11 in there (a T11 CPU) with something like 256kw of memory, 32k RAM > and the rest ROM chips. Which is impossible, however they built a bank > switching system into the terminal so the T11 could access more than 32kw of > memory. Yes, they literally built a MMU just so they could use a pdp11. > > The 11 seems to control the basic functions and the graphics modes (4014 > and REGIS/VT220/VT125) through the graphics chip controller which looks like > the same one on the Rainbow's expansion video board. However there is > also an 8085 in there that apparently generates the shape of text characters. > So they tossed in another processor because it's DEC.... > > Anyway I got out the thermal camera to see if there were any unusual shorts > or chips drawing a lot of current. And sure enough the 8085 was glowing > cherry red in the center. Felt it, it was hot and probably blown. > > So I bought a new CPU on Ebay, realized it was an 8085A instead of the > 8085-2 on the unit, bought an 8085-2 that will come next week, got the 8085a > and figured might as well try it. > > Popped it in, and the unit comes up! Set up works, ports work, I haven't > tested the 20ma current loop but that probably works too. This is pretty > much the most super terminal I've seen, and is classic DEC over-engineering. > But it works, and now I can spend some time thinking about what I might > want to DO with it. > > Moral: After testing the power supply try checking the board with an IR > camera. You can see a lot of interesting things with one. > Hello Chris, That's interesting. What did you use for the thermal camera? Regards Rob > Chris From robert.jarratt at ntlworld.com Sun May 1 05:37:31 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Sun, 1 May 2022 11:37:31 +0100 Subject: Testing a 74S240 In-Reply-To: <3.0.6.32.20220501102212.00e20c50@mail.optusnet.com.au> References: <011201d85ce1$2d7b4540$8871cfc0$@ntlworld.com> <3.0.6.32.20220501102212.00e20c50@mail.optusnet.com.au> Message-ID: <011c01d85d47$764f2870$62ed7950$@ntlworld.com> I am embarrassed to report that after trying all the suggestions etc, I then realised that I had connected the enable signal to pin 9 and not 19. I knew it was 19, I knew where 19 was, but for some unfathomable reason I connected it to 9 instead, despite checking multiple times. The original chip works. Sorry for the noise. Regards Rob > -----Original Message----- > From: Guy Dunphy > Sent: 01 May 2022 01:22 > To: rob at jarratt.me.uk; Rob Jarratt ; General > Discussion: On-Topic and Off-Topic Posts > Subject: Re: Testing a 74S240 > > At 11:25 PM 30/04/2022 +0100, you wrote: > >In trying to fix my M7133 CPU from my 11/24 I thought I had identified > >a failed 74S240. However, when I replaced it (while adding a socket), > >the fault remained. So, I guess the original chip may not be faulty. I > >decided to test the original chip on a breadboard to see if it is OK. > >This is where I got rather confused. > > > > > > > >I used a bench PSU, obviously connected Vcc to +5V and GND to the > >negative terminal. I connected pin 19 (the active low Enable ) to GND. > >And then I tested the particular pair of pins, 13 and 7. I did not > >connect any of the other pins. However, pin 7 seemed to hover around > >0.6 to 0.8V, no matter what I did with pin 13. I tried it with the > >replacement 74S240 and got the same result. I tried a second > >replacement 74S240 which had never been installed on the M7133 in case > >something on the CPU board was damaging it, and got the same result. > > > > > > > >I looked at the M7133 schematic and saw that pin 19 is connected to GND > >by a 180R resistor. I don't have one of that value so I tried a 220R. > >My understanding is that the resistor isn't completely necessary, but I > >tried anyway. However, the results were identical. I added a 220R to > >the input on pin 19 just in case, again to no avail. > > > > > > > >I noticed that the chip (original and replacement) was drawing > >100-110mA from the bench PSU, which seems a bit high. > > As others have mentioned, the supply current is normal. These are fast, high > power devices. > > When you say 'breadboard', what do you mean? Is it one of those blocky > things with rows of holes with metal connecting fingers inside? > Those have a lot of capacitance between rows, and with fast 74S logic and an > inverting buffers chip like the 74S240 that can be a problem. Also I bet you > didn't bother with a supply decoupling 0.1uF ceramic directly between Vcc > and Gnd at the IC. > > So be aware that you may have a circuit oscillating at something above > 20MHz, and your multimeter will just be showing averages. > To avoid this, add the supply cap and tie all unused inputs directly to Gnd. > With the input you are interested in, tie to Gnd or to Vcc via a 1K resistor. > All with _short_ wires. Also with your multimeter (on Volts range) it's a good > idea to have a 1K resistor in series with the probe tip AT THE TIP. Otherwise > your meter lead is a nice radiating antenna, and can cause oscillations with > that less than ideal breadboard. > The resistor won't affect voltage readings. > > Old 74xx logic (mostly) doesn't have these problems, and people used to that > get confused when much faster logic seems to be behaving weirdly. > > At least the IC won't blow up. I had an interesting learning experience the > first time I got hold of a 74AC series 20 pin buffer chip. I blithely > breadboarded it with just the power rails and turned on +5V. > BANG! the die exploded. Blew a nice big crater in the plastic. > Turns out with the fully CMOS inputs, they will float around in the zone > between 0 and 1, which causes the very powerful output drivers to draw > huge current as both the upper and lower drivers turn somewhat on. Times > eight... Instant silicon vaporization. > > After tying all the inputs to valid logic levels, no more explosions. > > Guy > From ard.p850ug1 at gmail.com Sun May 1 07:20:09 2022 From: ard.p850ug1 at gmail.com (Tony Duell) Date: Sun, 1 May 2022 13:20:09 +0100 Subject: Repairing a VT240. In-Reply-To: References: Message-ID: On Sun, May 1, 2022 at 2:57 AM Chris Zach via cctalk wrote: > Looking through the manual I saw that this thing is nuts: It has a full > pdp11 in there (a T11 CPU) with something like 256kw of memory, 32k RAM > and the rest ROM chips. Which is impossible, however they built a bank > switching system into the terminal so the T11 could access more than > 32kw of memory. Yes, they literally built a MMU just so they could use a > pdp11. I find it rather annoying that with that much processor power there is no way to run a user program on the VT240. Maybe there is, but I can find nothing about doing that in the manuals. > > The 11 seems to control the basic functions and the graphics modes (4014 > and REGIS/VT220/VT125) through the graphics chip controller which looks > like the same one on the Rainbow's expansion video board. However there It's very like the Rainbow colour graphics board. There are a couple of programmed PALs in the memory update logic and I seem to remember that the ones in the VT240 and those in the 'bow are either identical or at least very similar. -tony From kgober at gmail.com Sun May 1 09:01:22 2022 From: kgober at gmail.com (Kenneth Gober) Date: Sun, 1 May 2022 10:01:22 -0400 Subject: RT11 Freeware Collection In-Reply-To: <7566b733-3d18-089e-9000-3ebe3eccf17a@comcast.net> References: <7566b733-3d18-089e-9000-3ebe3eccf17a@comcast.net> Message-ID: On Sat, Apr 30, 2022 at 12:33 PM Douglas Taylor wrote: > I was able to mount the partitions (as shown below) and actually extract > the entire 65K partition to a *.dsk file that SIMH was able to mount and > read. > This is what I was trying to do. Get files from the RT11freewarev2 cd > into SIMH. From there I can get them to my real PDP11 hardware. > Some of the files are binary so this process is necessary. > > One comment - when you execute a mount command it takes a minute or 2 to > decompress the file, so be patient! > One question - How did you know how much to skip? > The README.TXT file said which 'logical' volumes within the physical device contained RT-11 filesystems, and it's known that each volume is 32MB (65536 512-byte blocks). If each 'logical' volume is 32MB you just multiply. volume 13 (numbered from 0) will start at 13*32MB = 416MB. The README also indicated that you could mount from the ISO directly using the DU device driver but I've never tried this myself. Presumably this would involve accessing DU13:, DU14:, etc. -ken From cz at alembic.crystel.com Sun May 1 11:19:19 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Sun, 1 May 2022 12:19:19 -0400 Subject: Repairing a VT240. In-Reply-To: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> References: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> Message-ID: On 5/1/2022 2:14 AM, Rob Jarratt wrote: > That's interesting. What did you use for the thermal camera? Seek Thermal connected to a Samsung Galaxy 6 Note. Works pretty well to spot hot components. I look for the relative temp differences, a bright red spot on a particular chip is something to investigate. From cctalk at beyondthepale.ie Sun May 1 09:48:29 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Sun, 01 May 2022 15:48:29 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: <01SCICHQ3UWC8WYB2W@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> Message-ID: <01SCOXM3RCV48X0MWD@beyondthepale.ie> I'm having a lot of problems with DEC power supplies. Newly failed ones are getting added to the end of the queue quicker than I am managing to pop fixed ones off the top of the queue :-( The latest one to give trouble is a H7822 in a MicroVAX 3100. This machine apparantly never got deployed for the purpose it was purchased for so it has had very little use and it is clean and pretty much dust free inside, including in the power supply. The two SCSI buses only worked intermittently when I got the machine first many years ago. Now, they seem to have failed completely. A single common fault seems to be responsible for both failures but I haven't been able to find it so I use it by accessing disks across the network instead which is a pity because it has lots of room inside for disks. A couple of years ago, the two fans in the H7822 (which are the only fans in the machine) stopped working leading to overheating and shutdown due overtemperature if it was left on for too long. This turned out to be due to a faulty 12V zener diode in the fan control circuit. I replaced the zener diode and that seemed to fix this particular problem. More recently, the machine was working away nicely when it suddenly stopped. Powering it off and back on later didn't help. Months later when I finally got around to looking at it, it still failed to do anything noticable when powered on. I took out the power supply, opened it up, checked for blown fuses or anything else obvious, found nothing, put it back together, applied power (without a load) and the fans started spinning indicating it now seemed to be working. Thinking there might be a short on the system board, I put it back into the MicroVAX, connected it up and powered it on. The fans spun, all the diagnostic LEDs lit and stayed on but the green LED on the power supply did not light. The machine appeared to be held in reset. There's probably a voltage missing from the power supply I thought. While I was getting the meter to check this theory, the green LED came on, the diagnostic LEDs began counting down and the output of the POST appeared on the console terminal. While I was making notes so that I didn't forget what happened, I noticed the fans stopping making noise, the green LED and diagnostic LEDs had all gone out and the console was no longer responsive. It had failed again. I put the meter on the front disk drive connector to check the voltages from the power supply. It showed +5V and +12V as if everything was normal. I put it on the rear disk drive connector and both lines were varying around one or two volts. I plugged in an AUI tranceiver which happened to be to hand and the LEDs on it varied with the meter readings. I tried connecting a test lamp to the +5V and +12V lines on the front disk drive connector to load it a bit. They held steady while the LEDs on the AUI tranceiver continued to vary. It seems there are at least two independent regulation systems in this power supply. I left things as they were and went to make more notes. A few minutes later, I heard the fans starting up again. I looked at the machine and the green LED on the power supply was on, the diagnostic LEDs were counting down, output was starting to appear on the console and the LEDs on the AUI tranceiver were lighting normally. I've tried power cycling it several times since and it doesn't seem to want to fail now. Access to the H7822 is not great. There are two boards (each with permanently connected daughter boards), one mounted in the base and one mounted in the lid. The boards are connected together at one end by about twenty flexible wires and at the other end by two two core cables which can be unplugged to allow the two boards to be laid out flat end to end. I suppose I could make up extensions to the two two core cables to enable better access for testing. However, it doesn't look easy to devise a layout where everything can be cooled by the fans for testing over an extended period of time. At least the H7822 does not seem to suffer from the leaky capacitor problem like the H7821 does. I have another MicroVAX 3100 which looks like it should have a H7822 in it too but I'm not sure how this could be helpful given the symptoms. Any suggestions on how to further diagnose this nightmare? Regards, Peter Coghlan. From cz at alembic.crystel.com Sun May 1 12:53:04 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Sun, 1 May 2022 13:53:04 -0400 Subject: Repairing a VT240. In-Reply-To: References: Message-ID: > I find it rather annoying that with that much processor power there is > no way to run a user program on the VT240. Maybe there is, but I can > find nothing about doing that in the manuals. "Power" is relative. If I recall the T11 was basically the four (five) Western Digital chips in one container that had the power of the mighty pdp11/03. Enough for a lot of basic stuff, but not so much a general purpose computer. That said, it looks like the design and interfaces are pretty well documented and it does have access to the serial port so you might be able to build a ROM that includes RT11 or some kind of ODT. I think the printer port is also accessible so if you were seriously.... driven you might be able to get it to boot off a TU58. > It's very like the Rainbow colour graphics board. There are a couple > of programmed PALs in the memory update logic and I seem to remember > that the ones in the VT240 and those in the 'bow are either identical > or at least very similar. Thought so. I just sold the Rainbow here, but I could see that the NEC graphics chip and a lot of the layout looked similar to the graphics on the Rainbow. I wonder if the Professional 380 AVO option used the same basic chipset. C From paulkoning at comcast.net Sun May 1 13:41:57 2022 From: paulkoning at comcast.net (Paul Koning) Date: Sun, 1 May 2022 14:41:57 -0400 Subject: Comtec model P135-20/35 Paper Tape Punch In-Reply-To: <281463572.2295575.1651358105063@email.ionos.com> References: <865552072.563080.1651342833165@email.ionos.com> <00cf01d85cc5$df327bd0$9d977370$@gmail.com> <281463572.2295575.1651358105063@email.ionos.com> Message-ID: > On Apr 30, 2022, at 6:35 PM, Will Cooke via cctalk wrote: > > > >> On 04/30/2022 2:09 PM amp1ron at gmail.com wrote: >> >> >> Hi Will, >> >> Is the punch you received capable of punching 8-level tape? While the PDF on Surplus Sales of Nebraska's site says the unit can punch 5- to 8-level tape, one of the photos on the site, https://www.surplussales.com/Images/Equipment/Military/eqp-p135-20-35_2_lg.jpg, makes it look like it can only punch up to 6-level tape. >> >> -- Ron >> > > It appears that it can only punch 6 (or 5?) level tape the way it is configured. The manual isn't very clear on it, specifying repeatedly that it can punch 5 to 8 level tape. But the one I got only has 6 holes as in the picture. In the back of the manual the parts list specifies different "guide and die blocks." I haven't hooked mine up yet -- I need a 5 amp, 27 V supply. But it appears it has everything except the die block to work with 8 level. I doubt the local electronic supply house will have that die block, so I might modify that one if possible. Safest might be to have a local machine shop make a new die block. The holes have to be bored accurately, and getting new ones to match with the existing ones might be harder than making a new block with the holes positioned properly. If you know any tool & die makers that would be the best way to get advice; I wish I had that kind of machining skills but I don't... paul From wrcooke at wrcooke.net Sun May 1 15:03:25 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Sun, 1 May 2022 15:03:25 -0500 (CDT) Subject: Comtec model P135-20/35 Paper Tape Punch In-Reply-To: References: <865552072.563080.1651342833165@email.ionos.com> <00cf01d85cc5$df327bd0$9d977370$@gmail.com> <281463572.2295575.1651358105063@email.ionos.com> Message-ID: <552526227.574414.1651435405620@email.ionos.com> > On 05/01/2022 2:28 PM Wayne S wrote: > > > Seconded. Punches have to be made to exact tolerances and should be made of a very hard material, (because they can quickly become dull ) that requires special machine tools to manufacture. > > Sorry, didn't mean to imply I would do it personally. That is beyond my abilities as well. I'm fortunate to have a close relative who is a machinist. But it's a moot question. AFter closer examination, the two extra solenoids are missing, so it can't punch 8 levels without adding those as well. Will From ccth6600 at gmail.com Sun May 1 22:59:43 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Mon, 2 May 2022 11:59:43 +0800 Subject: Repairing a VT240. In-Reply-To: References: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> Message-ID: The Seek Thermal is surprisingly expensive for what it is - a USB camera working in the infrared spectrum. On Mon, May 2, 2022 at 12:19 AM Chris Zach via cctalk wrote: > On 5/1/2022 2:14 AM, Rob Jarratt wrote: > > That's interesting. What did you use for the thermal camera? > > Seek Thermal connected to a Samsung Galaxy 6 Note. Works pretty well to > spot hot components. I look for the relative temp differences, a bright > red spot on a particular chip is something to investigate. > From cz at alembic.crystel.com Mon May 2 07:26:06 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Mon, 2 May 2022 08:26:06 -0400 Subject: Repairing a VT240. In-Reply-To: References: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> Message-ID: Feel free to recommend a better one. I repair electronics in my spare time, and it has paid for itself many times over. C On 5/1/2022 11:59 PM, Tom Hunter wrote: > The Seek Thermal is surprisingly expensive for what it is - a USB camera > working in the infrared spectrum. > > > On Mon, May 2, 2022 at 12:19 AM Chris Zach via cctalk > > wrote: > > On 5/1/2022 2:14 AM, Rob Jarratt wrote: > > That's interesting. What did you use for the thermal camera? > > Seek Thermal connected to a Samsung Galaxy 6 Note. Works pretty well to > spot hot components. I look for the relative temp differences, a bright > red spot on a particular chip is something to investigate. > From wrcooke at wrcooke.net Mon May 2 08:05:49 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Mon, 2 May 2022 08:05:49 -0500 (CDT) Subject: Comtec model P135-20/35 Paper Tape Punch In-Reply-To: <552526227.574414.1651435405620@email.ionos.com> References: <865552072.563080.1651342833165@email.ionos.com> <00cf01d85cc5$df327bd0$9d977370$@gmail.com> <281463572.2295575.1651358105063@email.ionos.com> <552526227.574414.1651435405620@email.ionos.com> Message-ID: <882346020.588572.1651496749213@email.ionos.com> I have done a quick and dirty scan of the manual. It is available here: http://wrcooke.net/comtec_p135_20_35_ppunch001.pdf Will From wrcooke at wrcooke.net Mon May 2 08:05:49 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Mon, 2 May 2022 08:05:49 -0500 (CDT) Subject: Comtec model P135-20/35 Paper Tape Punch In-Reply-To: <552526227.574414.1651435405620@email.ionos.com> References: <865552072.563080.1651342833165@email.ionos.com> <00cf01d85cc5$df327bd0$9d977370$@gmail.com> <281463572.2295575.1651358105063@email.ionos.com> <552526227.574414.1651435405620@email.ionos.com> Message-ID: <882346020.588572.1651496749213@email.ionos.com> I have done a quick and dirty scan of the manual. It is available here: http://wrcooke.net/comtec_p135_20_35_ppunch001.pdf Will From ccth6600 at gmail.com Mon May 2 09:17:23 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Mon, 2 May 2022 22:17:23 +0800 Subject: Repairing a VT240. In-Reply-To: References: <011701d85d22$b78a6040$269f20c0$@ntlworld.com> Message-ID: You misunderstood what I wrote. I just expressed surprise about the cost rather than criticizing your choice of thermal camera. Other brands are expensive too. I wonder what makes these cameras more expensive than ordinary USB cameras working in the visible spectrum. On Mon, May 2, 2022 at 8:26 PM Chris Zach wrote: > Feel free to recommend a better one. I repair electronics in my spare > time, and it has paid for itself many times over. > > C > > On 5/1/2022 11:59 PM, Tom Hunter wrote: > > The Seek Thermal is surprisingly expensive for what it is - a USB camera > > working in the infrared spectrum. > > > > > > On Mon, May 2, 2022 at 12:19 AM Chris Zach via cctalk > > > wrote: > > > > On 5/1/2022 2:14 AM, Rob Jarratt wrote: > > > That's interesting. What did you use for the thermal camera? > > > > Seek Thermal connected to a Samsung Galaxy 6 Note. Works pretty well > to > > spot hot components. I look for the relative temp differences, a > bright > > red spot on a particular chip is something to investigate. > > > From cctalk at beyondthepale.ie Mon May 2 09:58:07 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Mon, 02 May 2022 15:58:07 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: <01SCOXM3RCV48X0MWD@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> Message-ID: <01SCQATK0O3S8X0JVG@beyondthepale.ie> I wrote: > > At least the H7822 does not seem to suffer from the leaky capacitor problem > like the H7821 does. > Well, it's made a liar of me already. While checking over my previous work replacing the zener diode to make sure I didn't break something else, my eye was drawn to a ring of sticky brown goo around the base of one of the capacitors that looks the same as the ones that leak in the H7821. Thankfully, it doesn't seem to have been there long and didn't get a chance to spread around the board. Bizarrely this capacitor has it's legs pointing upwards and managed to leak while there are similar capacitors on the other board with their legs pointing downwards which don't seem to have leaked (yet?). When I compare them side by side, I can now see that the upper board in the H7822 is identical to the single board in the H7821. It seems that the lower board in the H7822 is only responsible for powering the front disk drive connector which I found to be independent of the other supplies. Regards, Peter Coghlan. From michael.99.thompson at gmail.com Mon May 2 13:10:12 2022 From: michael.99.thompson at gmail.com (Michael Thompson) Date: Mon, 2 May 2022 14:10:12 -0400 Subject: Comtec model P135-20/35 Paper Tape Punch In-Reply-To: References: Message-ID: Comtec was a tiny Rhode Island company that was owned by the family that used to live across the street from me. The RICM has a PDP-8/L powered document scanner that has a Comtec paper tape reader inside. Comtec was eventually bought by Zebra, another Rhode Island company that started out making badge printers. -- Michael Thompson From macro at orcam.me.uk Mon May 2 17:51:11 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Mon, 2 May 2022 23:51:11 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SCQATK0O3S8X0JVG@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> Message-ID: On Mon, 2 May 2022, Peter Coghlan via cctalk wrote: > Thankfully, it doesn't seem to have been there long and didn't get a chance > to spread around the board. Bizarrely this capacitor has it's legs pointing > upwards and managed to leak while there are similar capacitors on the other > board with their legs pointing downwards which don't seem to have leaked (yet?). Would the system have been possibly stored upside down sometime? These nasty caps do leak even while in storage (and even if never used, not even soldered ever, according to one source, a repair professional). Maciej From cctalk at beyondthepale.ie Tue May 3 10:04:51 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Tue, 03 May 2022 16:04:51 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> Message-ID: <01SCROBHOYWW8X0JVG@beyondthepale.ie> "Maciej W. Rozycki" wrote: >On Mon, 2 May 2022, Peter Coghlan via cctalk wrote: > >> Thankfully, it doesn't seem to have been there long and didn't get a chance >> to spread around the board. Bizarrely this capacitor has it's legs pointing >> upwards and managed to leak while there are similar capacitors on the other >> board with their legs pointing downwards which don't seem to have leaked (yet?). > > Would the system have been possibly stored upside down sometime? > I don't think so. It may have spent some time lying on it's side due to deteriorating rubber feet and for ease of access and but I can't see any reason for it ever being upside down. Once I discovered this issue a few years ago, I checked all my power supplies, removed any leaking capacitors and changed to storing the machines the right way up in a vertical stack, with newspapers between them in place of the rubber feet. I hoped this would prevent any capacitors which hadn't shown any signs of leaking from starting to leak. (Now whichever machine I want to work on always seems to be at the bottom of the stack...) > > These nasty caps do leak even while in storage (and even if never used, > not even soldered ever, according to one source, a repair professional). > They are nasty and devious. In my case, the ones that have been stored in any orientation but not used much seem to have fared better. I only started using this machine with the H7822 for extended periods for the first time a few months ago. One of the reasons I started using it more is because I thought it was immune to the leaky capacitor problem! It never saw any serious use before that, even when it was new. I have at least two machines with H7822 power supplies. Even though they have capacitors that look the same as the ones in the H7821, the ones in the H7822 power supplies didn't seem to be showing any signs of leaking when I examined them some time ago so I thought they might be from a batch that was unaffected by the problem. It seems that this was not true :-( I unsoldered the other eight similar capacitors (four one each board) from the H7822 yesterday evening. I found a small amount of leakage under most of them but it was was only evident after they were removed from the board. In general, there was less damage visible under the ones on the lower board with leads facing down oddly enough. I thought one of the capacitors from the upper board had not leaked at all. I left the removed capacitors standing on the bench overnight with their leads upwards and they all have some signs of leakage visible on them today. It's hard to draw any conclusions. The capacitor from the upper board that leaked enough for me to notice it might be under greater stress when operating than the others. I think the same capacitor in the H7821 power supplies seems to leak more in those too. Maybe it carries greater ripple current than the others or something like that? I can see that the other four similar capacitors make up PI filters for the +5V and +12V outputs along with a pair of smoothing chokes, however I can't quite figure out what the more leaky one is responsible for. It could be associated with the -12V output which might also be the supply for the fans. This part of the circuit is very hard to trace. I don't have enough spare capacitors to replace the four on the lower board. I am going to leave those out, leave the input lead to that board unplugged and plug the green LED into the upper board. I hope it will then behave just like a H7821. There won't be any power to the front disk drive connector but I am not using that so it doesn't matter unless the "power good" output is affected, in which case I will have to think of something else. I am hoping that the leaky capacitors were responsible for the odd intermittent failures I experienced with this power supply recently. Regards, Peter Coghlan. > Maciej From PETER at beyondthepale.ie Tue May 3 04:30:36 2022 From: PETER at beyondthepale.ie (Peter Coghlan) Date: Tue, 03 May 2022 10:30:36 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> Message-ID: <01SCRNTBXL828X0JVG@beyondthepale.ie> "Maciej W. Rozycki" wrote: >On Mon, 2 May 2022, Peter Coghlan via cctalk wrote: > >> Thankfully, it doesn't seem to have been there long and didn't get a chance >> to spread around the board. Bizarrely this capacitor has it's legs pointing >> upwards and managed to leak while there are similar capacitors on the other >> board with their legs pointing downwards which don't seem to have leaked (yet?). > > Would the system have been possibly stored upside down sometime? > I don't think so. It may have spent some time lying on it's side due to deteriorating rubber feet and for ease of access and but I can't see any reason for it ever being upside down. Once I discovered this issue a few years ago, I checked all my power supplies, removed any leaking capacitors and changed to storing the machines the right way up in a vertical stack, with newspapers between them in place of the rubber feet. I hoped this would prevent any capacitors which hadn't shown any signs of leaking from starting to leak. (Now whichever machine I want to use always seems to be at the bottom of the stack...) > > These nasty caps do leak even while in storage (and even if never used, > not even soldered ever, according to one source, a repair professional). > In my case, the ones that have been stored in any orientation but not used much seem to have fared better. I only started using this machine with the H7822 for extended periods for the first time a few months ago. One of the reasons I started using it more is because I thought it was immune to the leaky capacitor problem! It never saw any serious use before that, even when it was new. I have at least two machines with H7822 power supplies. Even though they have capacitors that look the same as the ones in the H7821, the ones in the H7822 power supplies didn't seem to be showing any signs of leaking when I examined them some time ago so I thought they might be from a batch that was unaffected by the problem. It seems that this was not the case :-( I unsoldered the eight other similar capacitors (four one each board) from the H7822 yesterday evening. I found a small amount of leakage under most of them but it was was only evident after they were removed from the board. In general, there was less damage visible under the ones on the lower board with leads facing down oddly enough. I thought one of the capacitors from the upper board had not leaked at all but I left them standing on the bench overnight with their leads upwards and they all have some signs of leakage visible on them today. The capacitor from the upper board that leaked enough for me to notice it might be under greater stress when operating than the others. I think the same capacitor in the H7821 power supplies seems to leak more in those too. Maybe it carries greater ripple current than the others or something like that? I can see that the other four similar capacitors make up PI filters for the +5V and +12V outputs along with a pair of smoothing chokes, however I can't quite figure out what the more leaky one is responsible for. It could be associated with the -12V output which might also be the supply for the fans. This part of the circuit is very hard to trace. I don't have enough spare capacitors to replace the four on the lower board. I am going to leave those out, leave the input lead to that board unplugged and plug the green LED into the upper board. I hope it will then behave just like a H7821. There won't be any power to the front disk drive connector but I am not using that so it doesn't matter unless the "power good" output is affected, in which case I will have to think of something else. I am hoping that the leaky capacitors were responsible for the odd intermittent failures I experienced with this power supply recently. Regards, Peter Coghlan. > Maciej From macro at orcam.me.uk Tue May 3 11:59:46 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Tue, 3 May 2022 17:59:46 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SCROBHOYWW8X0JVG@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> Message-ID: On Tue, 3 May 2022, Peter Coghlan via cctalk wrote: > > Would the system have been possibly stored upside down sometime? > > > > I don't think so. It may have spent some time lying on it's side due to > deteriorating rubber feet and for ease of access and but I can't see any > reason for it ever being upside down. Once I discovered this issue a few > years ago, I checked all my power supplies, removed any leaking capacitors > and changed to storing the machines the right way up in a vertical stack, > with newspapers between them in place of the rubber feet. I hoped this would > prevent any capacitors which hadn't shown any signs of leaking from starting > to leak. (Now whichever machine I want to work on always seems to be at the > bottom of the stack...) Lying on a side would also permit leaking, I've seen an H7821 damaged in storage that way. Gravity only helps with the leads up. > > These nasty caps do leak even while in storage (and even if never used, > > not even soldered ever, according to one source, a repair professional). > > > > They are nasty and devious. In my case, the ones that have been stored in > any orientation but not used much seem to have fared better. I only started > using this machine with the H7822 for extended periods for the first time a > few months ago. One of the reasons I started using it more is because I > thought it was immune to the leaky capacitor problem! It never saw any > serious use before that, even when it was new. From experience Chemi-con SXF caps used with many DEC PSUs need to be urgently replaced. Other Chemi-con lines reported affected are LXF, SXE and KME. Products of the time from other manufacturers may be affected as well. I'd have to check what line were those that leaked in a Bel Power PSU that I had to fix (I reckon you had a similar experience, right?). > I have at least two machines with H7822 power supplies. Even though they > have capacitors that look the same as the ones in the H7821, the ones in > the H7822 power supplies didn't seem to be showing any signs of leaking > when I examined them some time ago so I thought they might be from a batch > that was unaffected by the problem. It seems that this was not true :-( It was the composition of the electrolyte that was outright wrong, so I doubt it's batch-related. > I unsoldered the other eight similar capacitors (four one each board) from > the H7822 yesterday evening. I found a small amount of leakage under most > of them but it was was only evident after they were removed from the board. Yes, it's been a common case. > In general, there was less damage visible under the ones on the lower board > with leads facing down oddly enough. I thought one of the capacitors from > the upper board had not leaked at all. I left the removed capacitors > standing on the bench overnight with their leads upwards and they all have > some signs of leakage visible on them today. It's hard to draw any > conclusions. Once the seal has broken I guess all odds are off. I could imagine capillary action to take effect. > The capacitor from the upper board that leaked enough for me to notice it > might be under greater stress when operating than the others. I think the > same capacitor in the H7821 power supplies seems to leak more in those too. Heat dissipated by the cap itself under high ripple current never helps and will surely speed up cap deterioration. After all its service life halvens with each 10?C temperature rise even with non-faulty parts. > I don't have enough spare capacitors to replace the four on the lower > board. I am going to leave those out, leave the input lead to that board > unplugged and plug the green LED into the upper board. I hope it will then > behave just like a H7821. There won't be any power to the front disk drive > connector but I am not using that so it doesn't matter unless the "power good" > output is affected, in which case I will have to think of something else. As a matter of interest what capacitance/voltage are those? Are they of the Chemi-con/SXF type too? Maciej From mardy at me.com Tue May 3 12:30:11 2022 From: mardy at me.com (Marden Marshall) Date: Tue, 3 May 2022 13:30:11 -0400 Subject: ASR 33 For Sale Message-ID: I?m moving and just don?t have enough room. It is in great working condition having been professionally restored a few years back. The only issue is that someone dropped something onto the top cover and cracked the clear plastic window. I?m looking to get $800.00 for it. Local pickup only (Boston area) Thanks, -Mardy mardy at me.com (603) 264-1234 From spacewar at gmail.com Tue May 3 15:10:26 2022 From: spacewar at gmail.com (Eric Smith) Date: Tue, 3 May 2022 14:10:26 -0600 Subject: cleaning up edge connectors In-Reply-To: <7043DA26-746D-4A3B-A70A-9390922B88C5@pski.net> References: <7043DA26-746D-4A3B-A70A-9390922B88C5@pski.net> Message-ID: On Thu, Apr 28, 2022, 15:03 Peter Cetinski via cctalk wrote: > > TRS-80 guru Ian Mavric sells those gold connectors for the TRS-80. > > https://www.ebay.com/itm/164568343523 < > https://www.ebay.com/itm/164568343523> > They're made by Sullins, and may be orderable from Digi-Key and other distributors. I've bought them from Digi-Key in the past, but I think Digi-Key may have stopped stocking them. From cctalk at beyondthepale.ie Tue May 3 12:42:18 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Tue, 03 May 2022 18:42:18 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> Message-ID: <01SCS086KXDA8X0JVG@beyondthepale.ie> Hi Maciej, Thanks for your input. "Maciej W. Rozycki" wrote: > > Lying on a side would also permit leaking, I've seen an H7821 damaged in > storage that way. Gravity only helps with the leads up. > I have lots of H7821s that were on their side for a few years and leaked a lot but I also have H7822s that were stored the same way and did not show any evidence of leaking until very recently. I think I also have some H7821s that were the right way up most of their lives and have leaked a little. It's getting hard to remember what happened to which :-( > > From experience Chemi-con SXF caps used with many DEC PSUs need to be > urgently replaced. Other Chemi-con lines reported affected are LXF, SXE > and KME. Products of the time from other manufacturers may be affected as > well. I'd have to check what line were those that leaked in a Bel Power > PSU that I had to fix (I reckon you had a similar experience, right?). > I still have the leaky electrolytics I removed from the POWER-ONE PSU in my Cisco IGS a while back. I stored them with their leads up and goo seems to be still oozing out of some of them despite their inactivity and orientation. These ones are marked Nichicon PL(M) 4700uF/63V, 2200uF/16V and 330uF/35V and also have markings like H8950, H9018 and H8946 - maybe these are date codes? I also removed the smaller ones like 47uF/35V PF(M) H8952 for example but it is less clear to me whether these were leaking too or just got leaked on by the others. There were only a few of them so I decided they were better out than in. They all have similar coloured brown sleeves like the faulty ones in the DEC power supplies too. There are also the leaky 10uF/35V axial electrolytics in my LK201 keyboard. Those are in orange sleeves and marked "ESZ", whatever that is. They have date codes like 8612. I thought this might be a widespread problem but so far I have only found it in one keyboard. > > It was the composition of the electrolyte that was outright wrong, so I > doubt it's batch-related. > > > Once the seal has broken I guess all odds are off. I could imagine > capillary action to take effect. > Looks like I need to go back and recheck everything I thought wasn't leaking last time I checked :-( Thing is, to check them, they have to come out of the case and that involves at least some change in orientation, except for contortionists... > > Heat dissipated by the cap itself under high ripple current never helps > and will surely speed up cap deterioration. After all its service life > halvens with each 10?C temperature rise even with non-faulty parts. > When I was shopping for replacements, I was a bit alarmed to find that the maximum specified "endurance" (whatever that is) I could find was 5000 hours. This isn't much more than a long life incandescent light bulb. > > As a matter of interest what capacitance/voltage are those? Are they of > the Chemi-con/SXF type too? > All the leaking ones in DEC H7821 and H7822 PSUs I have come across so far are 1800uF/25V Chemicon with brown sleeves. I think mine are all SXF but I am not 100% sure of that. There are lots of other electrolytic capacitors in these power supplies but I've only looked closely at the larger ones. All of the reservoir capacitors attached to the mains bridge rectifiers that I have seen look fine. Maybe I need to go back and check the smaller ones though :-( I think I came across some LXF ones that seemed to be ok, I can't remember where though. I probably need to go find these and check them again :-( Here's a thought. Apart from the keyboard, all the ones I have seen that are leaking are filtering the outputs of switch mode power supplies. I wonder does the higher frequency of the ripple they are dealing with have a bearing on this? I replaced the five leaking capacitors on the upper board in my H7822, disconnected the input to the lower board and moved the LED connection to the upper board. The machine powered up nicely afterwards, the fans spun and the green LED came on after a short delay. However, the diagnostic LEDs all come on and stay on so it appears the CPU is being made aware that the lower board is not functioning, even though I don't need it. I should to do some comparisons with a H7821 and see if I can work around this. Or maybe I could fit some not quite to specification electrolytics from the junk box on the lower board, just to keep it happy? Regards, Peter Coghlan. > > Maciej > From bill.gunshannon at hotmail.com Wed May 4 13:28:10 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 4 May 2022 14:28:10 -0400 Subject: The TRS-80 Journey Continues Message-ID: Utterly amazed at how much I have forgotten. Even more amazed at how much information seems to have been lost since the days of the TRS-80. So, I am no trying to get CP/M going again. I have been able to get floppy systems working but can not find any information on how to build hard disk systems. I have both 2.2 and 3.0 (CP/M+) available but all of my software pre-dates the easy availability of hard drives so I seem to be missing the needed pieces for Montezuma Micro 2.2. 3.0 should support hard drives out of the box but I can't figure out how. Does anyone have any old documentation on how to do this? I would prefer 2.2 but I can probably do the stuff I want to play with under 3.0 as well. It's PL/M-80 and it is certainly fun to have it working again. bill From billdegnan at gmail.com Wed May 4 13:35:04 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 4 May 2022 14:35:04 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Bill, I searched for "montezuma 2.2 hard drive install" on Google: https://oldcomputers.dyndns.org/public/pub/manuals/montezuma_micro_hard_disk_support_for_cpm_2-2.pdf I have been through the process a few times, it's pretty straight-forward if you use these directions. Bill On Wed, May 4, 2022 at 2:28 PM Bill Gunshannon via cctalk wrote: > > > Utterly amazed at how much I have forgotten. > > Even more amazed at how much information seems to have been lost > since the days of the TRS-80. > > So, I am no trying to get CP/M going again. I have been able to > get floppy systems working but can not find any information on how > to build hard disk systems. I have both 2.2 and 3.0 (CP/M+) > available but all of my software pre-dates the easy availability > of hard drives so I seem to be missing the needed pieces for > Montezuma Micro 2.2. 3.0 should support hard drives out of the > box but I can't figure out how. > > Does anyone have any old documentation on how to do this? I would > prefer 2.2 but I can probably do the stuff I want to play with under > 3.0 as well. It's PL/M-80 and it is certainly fun to have it working > again. > > bill From bill.gunshannon at hotmail.com Wed May 4 13:50:02 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 4 May 2022 14:50:02 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/4/22 14:35, Bill Degnan wrote: > Bill, > I searched for "montezuma 2.2 hard drive install" on Google: > > https://oldcomputers.dyndns.org/public/pub/manuals/montezuma_micro_hard_disk_support_for_cpm_2-2.pdf > > I have been through the process a few times, it's pretty > straight-forward if you use these directions. > Yeah, I have that. But it requires pieces that are not in my distribution of MM 2.2 and attempts to find any of it on the web have proven unsuccessful. The one floppy image (MMRSHD,DSK) I found (in more than one place) that is supposed to have it seems to be corrupted. If you know where I can find FIXCPM and the hard drive DRIVERS I would greatly appreciate it. bill From billdegnan at gmail.com Wed May 4 14:10:23 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 4 May 2022 15:10:23 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Bill, Sorry, I understand now. Assuming you have the confirmed ability to make a disk from DSK image you found a corrupted DSK file. Gotcha. I am kind of busy at the moment, but I do have the disk you need, the actual disk. If you find no other source I could image mine for you. Otherwise you're welcome to bring your machine to Kennett Classic and do the work here. I just need a heads up to know to bring the disk for you that day. Bill Degnan On Wed, May 4, 2022 at 2:50 PM Bill Gunshannon via cctalk wrote: > > On 5/4/22 14:35, Bill Degnan wrote: > > Bill, > > I searched for "montezuma 2.2 hard drive install" on Google: > > > > https://oldcomputers.dyndns.org/public/pub/manuals/montezuma_micro_hard_disk_support_for_cpm_2-2.pdf > > > > I have been through the process a few times, it's pretty > > straight-forward if you use these directions. > > > > Yeah, I have that. But it requires pieces that are not in my > distribution of MM 2.2 and attempts to find any of it on the > web have proven unsuccessful. The one floppy image (MMRSHD,DSK) > I found (in more than one place) that is supposed to have it > seems to be corrupted. If you know where I can find FIXCPM and > the hard drive DRIVERS I would greatly appreciate it. > > > bill From bill.gunshannon at hotmail.com Wed May 4 14:14:49 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 4 May 2022 15:14:49 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/4/22 15:10, Bill Degnan wrote: > Bill, > Sorry, I understand now. Assuming you have the confirmed ability to > make a disk from DSK image you found a corrupted DSK file. Gotcha. I > am kind of busy at the moment, but I do have the disk you need, the > actual disk. If you find no other source I could image mine for you. > Otherwise you're welcome to bring your machine to Kennett Classic and > do the work here. I just need a heads up to know to bring the disk > for you that day. Thanks for the offer but I don't expect to be traveling much for the next few months (thus the reason for finding fun things to do to keep me busy). If you get a chance to image it, I would appreciate that. But no real hurry. After next week I won't be going anywhere but rehab. bill From mloewen at cpumagic.scol.pa.us Wed May 4 15:08:29 2022 From: mloewen at cpumagic.scol.pa.us (Mike Loewen) Date: Wed, 4 May 2022 16:08:29 -0400 (EDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Wed, 4 May 2022, Bill Gunshannon via cctalk wrote: > On 5/4/22 14:35, Bill Degnan wrote: >> Bill, >> I searched for "montezuma 2.2 hard drive install" on Google: >> >> https://oldcomputers.dyndns.org/public/pub/manuals/montezuma_micro_hard_disk_support_for_cpm_2-2.pdf >> >> I have been through the process a few times, it's pretty >> straight-forward if you use these directions. >> > > Yeah, I have that. But it requires pieces that are not in my > distribution of MM 2.2 and attempts to find any of it on the > web have proven unsuccessful. The one floppy image (MMRSHD,DSK) > I found (in more than one place) that is supposed to have it > seems to be corrupted. If you know where I can find FIXCPM and > the hard drive DRIVERS I would greatly appreciate it. The MMRSHD.DSK image is a Montezuma Micro Standard DATA disk (40T, SS, DD, 200K). I used the 'sdltrs' emulator to extract the files you need. I'll contact you directly with a ZIP file. Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/ From cz at alembic.crystel.com Wed May 4 15:40:13 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Wed, 4 May 2022 16:40:13 -0400 Subject: HP9825 internal ROM? Message-ID: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> Question for the group: I'm working on a HP9825B here. First thing I did was take it apart, clean it, unplug all the power connections to the board and test the power supply. Supply is good (values below) so after checking the boards I put it together and powered it on. Note: I can see the lack of a crowbar circuit on the +5 line and would be happy to install a crowbar circuit. Does anyone have a spare PCB board as otherwise I'd need to order at least three of them to build one. Voltages are still good, however I get nothing on the display. The CAPS LOCK does light up the caps lock light and it's cleared by pressing Shift but that's about it. Question: Is there supposed to be a ROM board or cartridge inside the unit by default? This one does not have one (the space between the front of the CPU board and the 4 card edges on the front). Perhaps that's the problem. If so is it possible to build a board that can contain a more modern ROM with the system code on it? Thanks! Chris Appendix: Power supply voltages: Blue +25 White -25 Red +5 yellow 11.97 white/red -5 white/yellow -12 orange 7 volts From phb.hfx at gmail.com Wed May 4 16:14:03 2022 From: phb.hfx at gmail.com (Paul Berger) Date: Wed, 4 May 2022 18:14:03 -0300 Subject: HP9825 internal ROM? In-Reply-To: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> References: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> Message-ID: <65b63f6e-2665-9efd-27f8-abf9f4153b43@gmail.com> The 9825B should have a board part number 09825-66524 with 16 DRAM chips and 10 24 pin ROM chips these ROM chips replace teh OS ROM module pluged into the right bottom of the machine and also most of the option ROMs.? You may also have a second board with another 16 DRAMs a a lot of other logic that is the memory expansion. Paul. On 2022-05-04 17:40, Chris Zach via cctalk wrote: > Question for the group: I'm working on a HP9825B here. First thing I > did was take it apart, clean it, unplug all the power connections to > the board and test the power supply. Supply is good (values below) so > after checking the boards I put it together and powered it on. > > Note: I can see the lack of a crowbar circuit on the +5 line and would > be happy to install a crowbar circuit. Does anyone have a spare PCB > board as otherwise I'd need to order at least three of them to build one. > > Voltages are still good, however I get nothing on the display. The > CAPS LOCK does light up the caps lock light and it's cleared by > pressing Shift but that's about it. > > Question: Is there supposed to be a ROM board or cartridge inside the > unit by default? This one does not have one (the space between the > front of the CPU board and the 4 card edges on the front). Perhaps > that's the problem. > > If so is it possible to build a board that can contain a more modern > ROM with the system code on it? > > Thanks! > Chris > > Appendix: Power supply voltages: > Blue +25 > White -25 > Red +5 > yellow 11.97 > white/red -5 > white/yellow -12 > orange 7 volts From a.carlini at ntlworld.com Wed May 4 16:56:22 2022 From: a.carlini at ntlworld.com (Antonio Carlini) Date: Wed, 4 May 2022 22:56:22 +0100 Subject: HP9825 internal ROM? In-Reply-To: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> References: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> Message-ID: <744b1205-930a-11f6-4ea7-e51d3237615f@ntlworld.com> On 04/05/2022 21:40, Chris Zach via cctalk wrote: > Question for the group: I'm working on a HP9825B here. First thing I > did was take it apart, clean it, unplug all the power connections to > the board and test the power supply. Supply is good (values below) so > after checking the boards I put it together and powered it on. > > Note: I can see the lack of a crowbar circuit on the +5 line and would > be happy to install a crowbar circuit. Does anyone have a spare PCB > board as otherwise I'd need to order at least three of them to build one. > > Voltages are still good, however I get nothing on the display. The > CAPS LOCK does light up the caps lock light and it's cleared by > pressing Shift but that's about it. > > Question: Is there supposed to be a ROM board or cartridge inside the > unit by default? This one does not have one (the space between the > front of the CPU board and the 4 card edges on the front). Perhaps > that's the problem. > > If so is it possible to build a board that can contain a more modern > ROM with the system code on it? CuriousMarc did a crowbar on youtube: https://www.youtube.com/watch?v=gIfJ30fPAOw. The circuit is available on his website: https://www.curiousmarc.com/computing/hp-9825-scientific-computer#h.xrov16yr03br The whole series was fun to watch (even though I don't have an HP9825) Antonio -- Antonio Carlini antonio at acarlini.com From cz at alembic.crystel.com Wed May 4 17:58:33 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Wed, 4 May 2022 18:58:33 -0400 Subject: HP9825 internal ROM? In-Reply-To: <65b63f6e-2665-9efd-27f8-abf9f4153b43@gmail.com> References: <9d5b4c1b-c9fc-e404-6efc-bb3b6eda867a@alembic.crystel.com> <65b63f6e-2665-9efd-27f8-abf9f4153b43@gmail.com> Message-ID: Hi Paul! Ok, so it should be coming up, but is not.... Hm. Without another unit to do comparisons with and a system that is not doing anything repeatable, trying to fix this little guy is probably outside my limit of "I have a limited amount of time in my life". I think I'll stick it on the Evil Bay and reserve the logic analysis on the DEC stuff I have. At least the power supply is fine so whatever is a dud isn't that... Thank you! CZ On 5/4/2022 5:14 PM, Paul Berger via cctalk wrote: > The 9825B should have a board part number 09825-66524 with 16 DRAM chips > and 10 24 pin ROM chips these ROM chips replace teh OS ROM module pluged > into the right bottom of the machine and also most of the option ROMs. > You may also have a second board with another 16 DRAMs a a lot of other > logic that is the memory expansion. > > Paul. From bill.gunshannon at hotmail.com Wed May 4 19:23:15 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 4 May 2022 20:23:15 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: My thanks for all the help. I now have CP/M 2.2 booting and running from a hard disk on a TRS-80 Model 4P, Now back to my PL/M. bill From billdegnan at gmail.com Wed May 4 19:25:39 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 4 May 2022 20:25:39 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: that's great news. Bill On Wed, May 4, 2022 at 8:23 PM Bill Gunshannon via cctalk wrote: > > > > My thanks for all the help. I now have CP/M 2.2 booting and running > from a hard disk on a TRS-80 Model 4P, Now back to my PL/M. > > bill From macro at orcam.me.uk Thu May 5 09:52:04 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Thu, 5 May 2022 15:52:04 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SCS086KXDA8X0JVG@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> Message-ID: Hi Peter, > I still have the leaky electrolytics I removed from the POWER-ONE PSU in my > Cisco IGS a while back. I stored them with their leads up and goo seems to > be still oozing out of some of them despite their inactivity and orientation. > These ones are marked Nichicon PL(M) 4700uF/63V, 2200uF/16V and 330uF/35V and > also have markings like H8950, H9018 and H8946 - maybe these are date codes? Right, my notes indicate Nichicon PL parts might be problematic too, e.g. one at 4700uF/10V on 5V output of the H7826 PSU. > I also removed the smaller ones like 47uF/35V PF(M) H8952 for example but it > is less clear to me whether these were leaking too or just got leaked on by > the others. There were only a few of them so I decided they were better out > than in. They all have similar coloured brown sleeves like the faulty ones > in the DEC power supplies too. I can confirm now Nichicon PF 47uF/35V parts to be the source of an issue with my Bel Power. All four leaked. Thankfully I was able to fully revive that PSU (now in 24/7 operation). > There are also the leaky 10uF/35V axial electrolytics in my LK201 keyboard. > Those are in orange sleeves and marked "ESZ", whatever that is. They have > date codes like 8612. I thought this might be a widespread problem but > so far I have only found it in one keyboard. These are likely standard type parts. I've yet to come across a low impedance axial capacitor type. I may have missed something of course. > Looks like I need to go back and recheck everything I thought wasn't leaking > last time I checked :-( > > Thing is, to check them, they have to come out of the case and that involves > at least some change in orientation, except for contortionists... I doubt a temporary reorientation of parts you want to replace anyway is going to cause any trouble in that short amount of time. > > Heat dissipated by the cap itself under high ripple current never helps > > and will surely speed up cap deterioration. After all its service life > > halvens with each 10?C temperature rise even with non-faulty parts. > > > > When I was shopping for replacements, I was a bit alarmed to find that > the maximum specified "endurance" (whatever that is) I could find was > 5000 hours. This isn't much more than a long life incandescent light bulb. Mind that it's at 105?C. If you keep such caps operating at 65?C (which is still rather hot), then endurance raises to 80000h (~9 years continuous use). Anyway try to chase replacements specified for at least 10000h at 105?C. Nichicon HE/UHE and Panasonic FR seem suitable replacements for Chemi-con SXF, Nichicon PL, surpassing old parts in terms of ESR/impedance/ripple and dimension-wise. > All the leaking ones in DEC H7821 and H7822 PSUs I have come across so far > are 1800uF/25V Chemicon with brown sleeves. I think mine are all SXF > but I am not 100% sure of that. There are lots of other electrolytic > capacitors in these power supplies but I've only looked closely at the > larger ones. All of the reservoir capacitors attached to the mains bridge > rectifiers that I have seen look fine. Maybe I need to go back and check > the smaller ones though :-( I don't have any H7822 PSU. Your experience with the H7821 is the same as mine though (and I still need to figure out what's wrong with one which still doesn't drive its power-good line active after recapping). I used Nichicon HE P/N UHE1E182MHD as the replacement for those. There does appear to be COVID-related shortage of this part (600 expected at Mouser 15/03/2023, ugh!), which used to be readily available in large quantities several years ago. However Panasonic FR P/N EEUFR1E182 is available in a small quantity (and is better). > I think I came across some LXF ones that seemed to be ok, I can't remember > where though. I probably need to go find these and check them again :-( I came across LXF parts in one H7826 only and they were clean, but I chose to replace them as a precaution anyway as I've got stuck with trying to repair a couple of broken H7826 PSUs already still not working after cleaning the mess and replacing broken caps (mind that I'm a software engineer with enough hassle to sort out on the software side already). > Here's a thought. Apart from the keyboard, all the ones I have seen that > are leaking are filtering the outputs of switch mode power supplies. I > wonder does the higher frequency of the ripple they are dealing with have > a bearing on this? I've seen leaks from SXF parts on the primary side too with the H7826, so it is not that they only fail on the secondary side. Also it is lower frequency ripple that's more problematic, see frequency correction factors for ripple current in datasheets, because impedance is higher at lower frequencies. That's an inherent property of capacitance. > I replaced the five leaking capacitors on the upper board in my H7822, > disconnected the input to the lower board and moved the LED connection to > the upper board. The machine powered up nicely afterwards, the fans spun > and the green LED came on after a short delay. However, the diagnostic > LEDs all come on and stay on so it appears the CPU is being made aware that > the lower board is not functioning, even though I don't need it. I should > to do some comparisons with a H7821 and see if I can work around this. Or > maybe I could fit some not quite to specification electrolytics from the > junk box on the lower board, just to keep it happy? The symptom is exactly like with my broken H7821. Check the power-good signal (brown wire with the H7821, possibly likewise with the H7822). It should be driven high at the TTL level. Maciej From ibmsystem3 at hccnet.nl Thu May 5 11:10:25 2022 From: ibmsystem3 at hccnet.nl (IBM System/3) Date: Thu, 5 May 2022 18:10:25 +0200 Subject: IBM 3725 MOSS cpu Message-ID: <897a7574-a6d2-376c-0b26-3c82f97141ca@hccnet.nl> Hi, Has anyone any information of the type CPU IBM used for the MOSS function in the IBM 3720/3725 ? Thanks ! Henk From billdegnan at gmail.com Thu May 5 11:30:34 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Thu, 5 May 2022 12:30:34 -0400 Subject: IBM 3725 MOSS cpu In-Reply-To: <897a7574-a6d2-376c-0b26-3c82f97141ca@hccnet.nl> References: <897a7574-a6d2-376c-0b26-3c82f97141ca@hccnet.nl> Message-ID: Dave McGuire would know this. I can look it up if no one else knows off the top of their head... Bil On Thu, May 5, 2022 at 12:10 PM IBM System/3 via cctalk wrote: > > Hi, > > Has anyone any information of the type CPU IBM used for the MOSS > function in the IBM 3720/3725 ? > > Thanks ! > > Henk > From bill.gunshannon at hotmail.com Thu May 5 11:55:21 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Thu, 5 May 2022 12:55:21 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Next step... Apparently mu original Tandon floppy has bought the farm. Does anyone know what the jumper setting are for a TEAC FD-55GFR-149 for the TRS-80 4P? I tried the usual (like for a DEC RX-33) but that didn't fly. Every sector fails verify after a format. I am sure it's a jumper thing. bill From barythrin at gmail.com Thu May 5 12:03:28 2022 From: barythrin at gmail.com (John Herron) Date: Thu, 5 May 2022 12:03:28 -0500 Subject: Different font for second 1 on commodore 1571 drives (and others) Message-ID: Someone at work pointed this out and I've never really thought about it. Is anyone here aware of the decision or reason to use a different 1 character for the last 1 vs the first 1? From toby at telegraphics.com.au Thu May 5 12:26:09 2022 From: toby at telegraphics.com.au (Toby Thain) Date: Thu, 5 May 2022 13:26:09 -0400 Subject: Different font for second 1 on commodore 1571 drives (and others) In-Reply-To: References: Message-ID: <520dc50f-9289-c85f-b9a3-aab952bfff45@telegraphics.com.au> On 2022-05-05 1:03 p.m., John Herron via cctalk wrote: > Someone at work pointed this out and I've never really thought about it. Is > anyone here aware of the decision or reason to use a different 1 character > for the last 1 vs the first 1? Got a picture? From mloewen at cpumagic.scol.pa.us Thu May 5 12:34:27 2022 From: mloewen at cpumagic.scol.pa.us (Mike Loewen) Date: Thu, 5 May 2022 13:34:27 -0400 (EDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: > Next step... > > Apparently mu original Tandon floppy has bought the farm. > Does anyone know what the jumper setting are for a > TEAC FD-55GFR-149 for the TRS-80 4P? > > I tried the usual (like for a DEC RX-33) but that didn't > fly. Every sector fails verify after a format. I am sure > it's a jumper thing. The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used 360K drives (possibly Teac FD-55A), single-sided as installed at the factory. Are you sure that's the model number that was in your 4P? Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/ From jrr at flippers.com Thu May 5 12:43:36 2022 From: jrr at flippers.com (John Robertson) Date: Thu, 5 May 2022 10:43:36 -0700 Subject: Different font for second 1 on commodore 1571 drives (and others) In-Reply-To: <520dc50f-9289-c85f-b9a3-aab952bfff45@telegraphics.com.au> References: <520dc50f-9289-c85f-b9a3-aab952bfff45@telegraphics.com.au> Message-ID: On 2022/05/05 10:26 a.m., Toby Thain via cctalk wrote: > On 2022-05-05 1:03 p.m., John Herron via cctalk wrote: >> Someone at work pointed this out and I've never really thought about >> it. Is >> anyone here aware of the decision or reason to use a different 1 >> character >> for the last 1 vs the first 1? > > Got a picture? They may have run out of that original font if they were setting the type with something like Lettraset in the day. I restore and sell the first coin operated video game - Nutting's Computer Space - and they mixed all sorts of fonts on the control panel. It was a pain to reproduce it! John :-#)# -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out" From bill.gunshannon at hotmail.com Thu May 5 13:16:13 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Thu, 5 May 2022 14:16:13 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/5/22 13:34, Mike Loewen via cctalk wrote: > On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: > >> Next step... >> >> Apparently mu original Tandon floppy has bought the farm. >> Does anyone know what the jumper setting are for a >> TEAC FD-55GFR-149 for the TRS-80 4P? >> >> I tried the usual (like for a DEC RX-33) but that didn't >> fly.? Every sector fails verify after a format.? I am sure >> it's a jumper thing. > > ?? The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used 360K > drives (possibly Teac FD-55A), single-sided as installed at the factory. > Are you sure that's the model number that was in your 4P? I know it wasn't. The original was a Tandon 50. But the TEAC FD-55GFR (in various flavors) was used in a lot of systems and at least one website said they were used in the 4P. It is an extremely configurable drive that I have used for numerous DEC systems (even the infamous RX50!) I have several of them and it should work just fine if I can find the magic jumper combination. bill From cisin at xenosoft.com Thu May 5 15:28:35 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Thu, 5 May 2022 13:28:35 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >>> Next step... >>> Apparently mu original Tandon floppy has bought the farm. >>> Does anyone know what the jumper setting are for a >>> TEAC FD-55GFR-149 for the TRS-80 4P? >>> I tried the usual (like for a DEC RX-33) but that didn't >>> fly.? Every sector fails verify after a format.? I am sure >>> it's a jumper thing. > On 5/5/22 13:34, Mike Loewen via cctalk wrote: >> ?? The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used 360K >> drives (possibly Teac FD-55A), single-sided as installed at the factory. >> Are you sure that's the model number that was in your 4P? On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: > I know it wasn't. The original was a Tandon 50. But the TEAC > FD-55GFR (in various flavors) was used in a lot of systems and > at least one website said they were used in the 4P. It is an > extremely configurable drive that I have used for numerous DEC > systems (even the infamous RX50!) I have several of them and > it should work just fine if I can find the magic jumper combination. The Teac FD-55GFR is a 96tpi drive. It can replace a 55G (1.2M), or a 55F (720K) depending on controller, but it still has a narrow head for doing 80 tracks. It will have to be jumpered to run at 300RPM, not 360. The FD-55B is double sided 48tpi ("360K"), and can be used in the 4P. I don't know what, if anything needs to be done to use double sided in a 4P (software patches? jumpers on disk controller?), but people DID. It's a worthwhile modification to do. The 4D, and the later models of the 4P used Teac double sided drives (55B?) On the other TRS80 models, the drive select jumpering was a little odd (although nor as odd as PC). Like IBM, later, Radio Shack did not want to trust their people to be able to do the drive select jumpers. So, they jumpered DS0, DS1, DS2, and used side select as DS3 on model 1!, then used a cable with the other drive selects removed. So, with the stock cable, the first drive should work as DS0, but jumpers of DS1 and DS2 won't have any effect. https://www.tim-mann.org/trs80faq.html#[19] Discusses the drive selects and Mentions that you can use 55GFR, but doesn't give the details that you need (300/360 RPM, double stepping, etc.) But, more importantly, is the fault ONLY when format/verify? Does it still READ disks that you already have? One more possibility to pay attention, (you probably already know this, so sorry if saying it offends you), ... You need to use 300 Oerstedt ("360K") diskettes. If you use 600 Oersted (1.2M) disks, they will seem to work, and then immediately, or VERY soon, lose their content. From bitwiz at 12bitsbest.com Thu May 5 15:50:01 2022 From: bitwiz at 12bitsbest.com (Mike Katz) Date: Thu, 5 May 2022 15:50:01 -0500 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: <9b524b14-b1ee-0035-7759-1dc08ce877a0@12bitsbest.com> If you use a 80 track (96 TPI) 5 1/4" drive to read 40 track (48 PTI) floppies that will work but if you write onto them they will not be readable in a 40 track drive any more.?? The reason for this is that the had is half the width and when the 80 track drives writes to a 40 track written disk it only overwrites half of the track.? And when the 40 track drive goes to read the data it sees nothing but noise because the two halves of the track are different. If you want to write floppies on an 80 track drive and read them on a 40 track drive.? Magnetically erase the disks with a demagnetizer and then format the disk in the 80 track drive but double stepping the format. Double stepping means writing track zero on physical track zero and then writing track 1 on physical track 2 and track 2 on physical track 4, etc. This avoids the problem of tracks with different data on each half of the track.? The 40 track drive will only see the half track data. Not all operating systems nor drivers can handle this. Gimix Flex for the 6809 could handle this as a special configuration. I'm sure you could get the greaseweasel to support this also. I hope this helps. On 5/5/2022 3:28 PM, Fred Cisin via cctalk wrote: >>>> Next step... >>>> Apparently mu original Tandon floppy has bought the farm. >>>> Does anyone know what the jumper setting are for a >>>> TEAC FD-55GFR-149 for the TRS-80 4P? >>>> I tried the usual (like for a DEC RX-33) but that didn't >>>> fly.? Every sector fails verify after a format.? I am sure >>>> it's a jumper thing. > >> On 5/5/22 13:34, Mike Loewen via cctalk wrote: >>> ??? The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used >>> 360K drives (possibly Teac FD-55A), single-sided as installed at the >>> factory. Are you sure that's the model number that was in your 4P? > > On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: >> I know it wasn't.? The original was a Tandon 50.? But the TEAC >> FD-55GFR (in various flavors) was used in a lot of systems and >> at least one website said they were used in the 4P.? It is an >> extremely configurable drive that I have used for numerous DEC >> systems (even the infamous RX50!)? I have several of them and >> it should work just fine if I can find the magic jumper combination. > > The Teac FD-55GFR is a 96tpi drive.? It can replace a 55G (1.2M), or a > 55F (720K) depending on controller, but it still has a narrow head for > doing 80 tracks.?? It will have to be jumpered to run at 300RPM, not 360. > > The FD-55B is double sided 48tpi ("360K"), and can be used in the 4P. > I don't know what, if anything needs to be done to use double sided in > a 4P (software patches? jumpers on disk controller?), but people DID. > It's a worthwhile modification to do. > The 4D, and the later models of the 4P used Teac double sided drives > (55B?) > > On the other TRS80 models, the drive select jumpering was a little odd > (although nor as odd as PC).? Like IBM, later, Radio Shack did not > want to trust their people to be able to do the drive select jumpers.? > So, they jumpered DS0, DS1, DS2, and used side select as DS3 on model > 1!, then used a cable with the other drive selects removed.? So, with > the stock cable, the first drive should work as DS0, but jumpers of > DS1 and DS2 won't have any effect. > https://www.tim-mann.org/trs80faq.html#[19] > Discusses the drive selects and Mentions that you can use 55GFR, but > doesn't give the details that you need? (300/360 RPM, double stepping, > etc.) > > > But, more importantly, is the fault ONLY when format/verify? > Does it still READ disks that you already have? > > > One more possibility to pay attention, (you probably already know > this, so sorry if saying it offends you), ... > You need to use 300 Oerstedt ("360K") diskettes.? If you use 600 > Oersted (1.2M) disks, they will seem to work, and then immediately, or > VERY soon, lose their content. From toby at telegraphics.com.au Thu May 5 15:53:32 2022 From: toby at telegraphics.com.au (Toby Thain) Date: Thu, 5 May 2022 16:53:32 -0400 Subject: Different font for second 1 on commodore 1571 drives (and others) In-Reply-To: References: <520dc50f-9289-c85f-b9a3-aab952bfff45@telegraphics.com.au> Message-ID: <109f1a63-c2ee-255a-f86d-d911b65eca77@telegraphics.com.au> On 2022-05-05 1:43 p.m., John Robertson via cctalk wrote: > On 2022/05/05 10:26 a.m., Toby Thain via cctalk wrote: >> On 2022-05-05 1:03 p.m., John Herron via cctalk wrote: >>> Someone at work pointed this out and I've never really thought about >>> it. Is >>> anyone here aware of the decision or reason to use a different 1 >>> character >>> for the last 1 vs the first 1? >> >> Got a picture? > > They may have run out of that original font if they were setting the > type with something like Lettraset in the day. An easy contemporary solution to that would have been to use a process camera and make a copy. However, based on this picture: http://dunfield.classiccmp.org/c64/h/diskf.jpg , there *is* a good typographic reason to cut the serif off the second '1'; if you didn't, it would look ridiculous. The typographer's rule is, "If it _looks_ right, it _is_ right," and the decal as shipped looks fine, typographically. We make these slight "adjustments" all the time, it's a big part of the job (especially for logos) - and reveals that a professional was involved. Usually people don't even notice them, because that's the other rule of typography. --Toby > > I restore and sell the first coin operated video game - Nutting's > Computer Space - and they mixed all sorts of fonts on the control panel. > It was a pain to reproduce it! > > John :-#)# > From w9gb at icloud.com Thu May 5 13:12:48 2022 From: w9gb at icloud.com (Gregory Beat) Date: Thu, 5 May 2022 13:12:48 -0500 Subject: HP9825 internal ROM? Message-ID: Curious Marc has a complete set of YouTube videos on his restoration of the HP 9825, due to Power Supply failure (no crowbar) damaging a number of ICs. The Last video of the series shows fabricated of the PC Board for it?s missing Crowbar Circuit. https://youtu.be/gIfJ30fPAOw HP 9825 Crowbar Protection Circuit Project (Schematic, Parts, Gerbers, etc. https://www.curiousmarc.com/computing/hp-9825-scientific-computer#h.xrov16yr03br You can Order the PC Board from PCBWay https://www.pcbway.com/project/shareproject/HP_09825_66552_Crowbar_Protecton_Circuit_for_the_HP_9825_Vintage_Calculator_a244bde6.html greg chicago == Date: Wed, 4 May 2022 16:40:13 -0400 From: Chris Zach To: CCTalk mailing list Subject: HP9825 internal ROM? Question for the group: I'm working on a HP9825B here. First thing I did was take it apart, clean it, unplug all the power connections to the board and test the power supply. Supply is good (values below) so after checking the boards I put it together and powered it on. Note: I can see the lack of a crowbar circuit on the +5 line and would be happy to install a crowbar circuit. Does anyone have a spare PCB board as otherwise I'd need to order at least three of them to build one. Voltages are still good, however I get nothing on the display. The CAPS LOCK does light up the caps lock light and it's cleared by pressing Shift but that's about it. Question: Is there supposed to be a ROM board or cartridge inside the unit by default? This one does not have one (the space between the front of the CPU board and the 4 card edges on the front). Perhaps that's the problem. If so is it possible to build a board that can contain a more modern ROM with the system code on it? Thanks! Chris From paulkoning at comcast.net Thu May 5 16:10:44 2022 From: paulkoning at comcast.net (Paul Koning) Date: Thu, 5 May 2022 17:10:44 -0400 Subject: Different font for second 1 on commodore 1571 drives (and others) In-Reply-To: <109f1a63-c2ee-255a-f86d-d911b65eca77@telegraphics.com.au> References: <520dc50f-9289-c85f-b9a3-aab952bfff45@telegraphics.com.au> <109f1a63-c2ee-255a-f86d-d911b65eca77@telegraphics.com.au> Message-ID: > On May 5, 2022, at 4:53 PM, Toby Thain via cctalk wrote: > > On 2022-05-05 1:43 p.m., John Robertson via cctalk wrote: >> On 2022/05/05 10:26 a.m., Toby Thain via cctalk wrote: >>> On 2022-05-05 1:03 p.m., John Herron via cctalk wrote: >>>> Someone at work pointed this out and I've never really thought about it. Is >>>> anyone here aware of the decision or reason to use a different 1 character >>>> for the last 1 vs the first 1? >>> >>> Got a picture? >> They may have run out of that original font if they were setting the type with something like Lettraset in the day. > > An easy contemporary solution to that would have been to use a process camera and make a copy. > > However, based on this picture: http://dunfield.classiccmp.org/c64/h/diskf.jpg , there *is* a good typographic reason to cut the serif off the second '1'; if you didn't, it would look ridiculous. The typographer's rule is, "If it _looks_ right, it _is_ right," and the decal as shipped looks fine, typographically. We make these slight "adjustments" all the time, it's a big part of the job (especially for logos) - and reveals that a professional was involved. Usually people don't even notice them, because that's the other rule of typography. There are other examples in our field of lettering that changes according to context: the font used by DEC on the PDP-11 handbook covers and a number of peripheral device panels. The letters "t" come in "big loop" and "small loop" forms. The big loop is used when there isn't another letter after; the small loop is used to avoid looking silly when another letter follows. Look at "digital equipment corporation" on the inside cover page of the PDP-11 processor and peripheral handbooks, it shows it clearly. I digitized that font and gave the same treatment to f, j and r, though I haven't seen those differentiated in the examples I looked at. paul From cisin at xenosoft.com Thu May 5 16:12:41 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Thu, 5 May 2022 14:12:41 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Double sided drives in 4P shouldn't require anything more than software patches, to tell the OS (TRS-DOS, CP/M, etc.) that you have and want to use the other side. The Model 3 and 4 disk controller (did the 4P use the same one??) supports double sided and uses pin32 as side select (as deity intended). Therefore, of course, using a drive that was jumpered for model 1 will require removing the pin 32 jumper that model 1 used as DS3. https://www.retrotechnology.com/herbs_stuff/Model4_35_Drives.pdf (includes model 3/4 FDC pinout) This includes the 300RPM jumpering for [SEVERAL VARIANTS OF] 55GFR: http://www.oldskool.org/disk2fdi/525HDMOD.htm The links on it to TEAC maanuals seem to no longer be supported by Teac. To test the suspect drive, you could connect it to a PC; with DS1 jumpered (instead of DS0), it should work as a "180K" (single sided "360K"). From mloewen at cpumagic.scol.pa.us Thu May 5 17:09:22 2022 From: mloewen at cpumagic.scol.pa.us (Mike Loewen) Date: Thu, 5 May 2022 18:09:22 -0400 (EDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: > On 5/5/22 13:34, Mike Loewen via cctalk wrote: >> On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: >> >>> Next step... >>> >>> Apparently mu original Tandon floppy has bought the farm. >>> Does anyone know what the jumper setting are for a >>> TEAC FD-55GFR-149 for the TRS-80 4P? >>> >>> I tried the usual (like for a DEC RX-33) but that didn't >>> fly.? Every sector fails verify after a format.? I am sure >>> it's a jumper thing. >> >> ?? The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used 360K >> drives (possibly Teac FD-55A), single-sided as installed at the factory. >> Are you sure that's the model number that was in your 4P? > > I know it wasn't. The original was a Tandon 50. But the TEAC > FD-55GFR (in various flavors) was used in a lot of systems and > at least one website said they were used in the 4P. It is an > extremely configurable drive that I have used for numerous DEC > systems (even the infamous RX50!) I have several of them and > it should work just fine if I can find the magic jumper combination. > > bill This article talks about settings for the FD-55GFR on page 41: https://www.tim-mann.org/trs80/doc/TMQ%20Vol%20VII.i.pdf Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/ From bill.gunshannon at hotmail.com Thu May 5 17:27:51 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Thu, 5 May 2022 18:27:51 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/5/22 16:28, Fred Cisin via cctalk wrote: >>>> Next step... >>>> Apparently mu original Tandon floppy has bought the farm. >>>> Does anyone know what the jumper setting are for a >>>> TEAC FD-55GFR-149 for the TRS-80 4P? >>>> I tried the usual (like for a DEC RX-33) but that didn't >>>> fly.? Every sector fails verify after a format.? I am sure >>>> it's a jumper thing. > >> On 5/5/22 13:34, Mike Loewen via cctalk wrote: >>> ??? The FD-55GFR is a 1.2MB drive, double-sided. The Model 4P used >>> 360K drives (possibly Teac FD-55A), single-sided as installed at the >>> factory. Are you sure that's the model number that was in your 4P? > > On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: >> I know it wasn't.? The original was a Tandon 50.? But the TEAC >> FD-55GFR (in various flavors) was used in a lot of systems and >> at least one website said they were used in the 4P.? It is an >> extremely configurable drive that I have used for numerous DEC >> systems (even the infamous RX50!)? I have several of them and >> it should work just fine if I can find the magic jumper combination. > > The Teac FD-55GFR is a 96tpi drive.? It can replace a 55G (1.2M), or a > 55F (720K) depending on controller, but it still has a narrow head for > doing 80 tracks.?? It will have to be jumpered to run at 300RPM, not 360. It has a jumper that leave that up to the controller. > > The FD-55B is double sided 48tpi ("360K"), and can be used in the 4P. > I don't know what, if anything needs to be done to use double sided in a > 4P (software patches? jumpers on disk controller?), but people DID. > It's a worthwhile modification to do. > The 4D, and the later models of the 4P used Teac double sided drives (55B?) I used double sided as far back as my first Model III. Even had a full height Tandon 80 track double sided drive. All I ever needed was DOSPLUS or NEWDOS80. > > On the other TRS80 models, the drive select jumpering was a little odd > (although nor as odd as PC).? Like IBM, later, Radio Shack did not want > to trust their people to be able to do the drive select jumpers.? So, > they jumpered DS0, DS1, DS2, and used side select as DS3 on model 1!, > then used a cable with the other drive selects removed.? So, with the > stock cable, the first drive should work as DS0, but jumpers of DS1 and > DS2 won't have any effect. https://www.tim-mann.org/trs80faq.html#[19] > Discusses the drive selects and Mentions that you can use 55GFR, but > doesn't give the details that you need? (300/360 RPM, double stepping, > etc.) The 4P has the missing pins. I never liked it and usually end out putting in real cables and using Drive Select like it was intended. At least until IBM won and the started making 3.5" drives without any way to do drive select. > > > But, more importantly, is the fault ONLY when format/verify? > Does it still READ disks that you already have? Haven't really tried that. Most of the disks I have are over 20 years old. If it fails to read who's fault is it? The drive or the disk. > > > One more possibility to pay attention, (you probably already know this, > so sorry if saying it offends you), ... > You need to use 300 Oerstedt ("360K") diskettes.? If you use 600 Oersted > (1.2M) disks, they will seem to work, and then immediately, or VERY > soon, lose their content. Yeah, I knew about that. I still have piles of real floppies laying around. :-) bill From bill.gunshannon at hotmail.com Thu May 5 17:41:38 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Thu, 5 May 2022 18:41:38 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: <9b524b14-b1ee-0035-7759-1dc08ce877a0@12bitsbest.com> References: <9b524b14-b1ee-0035-7759-1dc08ce877a0@12bitsbest.com> Message-ID: On 5/5/22 16:50, Mike Katz via cctalk wrote: > If you use a 80 track (96 TPI) 5 1/4" drive to read 40 track (48 PTI) > floppies that will work but if you write onto them they will not be > readable in a 40 track drive any more.?? The reason for this is that the > had is half the width and when the 80 track drives writes to a 40 track > written disk it only overwrites half of the track.? And when the 40 > track drive goes to read the data it sees nothing but noise because the > two halves of the track are different. Well known and documented back when we first started using 80 track drives. > > If you want to write floppies on an 80 track drive and read them on a 40 > track drive.? Magnetically erase the disks with a demagnetizer and then > format the disk in the 80 track drive but double stepping the format. I always erase floppies with my tape degauser before formatting. Even new disks usually have some pattern written on them. > > Double stepping means writing track zero on physical track zero and then > writing track 1 on physical track 2 and track 2 on physical track 4, etc. > > This avoids the problem of tracks with different data on each half of > the track.? The 40 track drive will only see the half track data. > > Not all operating systems nor drivers can handle this. > > Gimix Flex for the 6809 could handle this as a special configuration. > > I'm sure you could get the greaseweasel to support this also. I just got a GreaseWeazle. Not impressed so far. > > I hope this helps. > All information helps. bill From bill.gunshannon at hotmail.com Thu May 5 17:49:08 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Thu, 5 May 2022 18:49:08 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/5/22 17:12, Fred Cisin via cctalk wrote: > Double sided drives in 4P shouldn't require anything more than software > patches, to tell the OS (TRS-DOS, CP/M, etc.) that you have and want to > use the other side. > > The Model 3 and 4 disk controller (did the 4P use the same one??) > supports double sided and uses pin32 as side select (as deity intended). Pretty much. > > Therefore, of course, using a drive that was jumpered for model 1 will > require removing the pin 32 jumper that model 1 used as DS3. While I have Model I's I never got into the modification stuff. Today I prefer to use things like MISE and FreHD (which also has a problem, need to get in touch with Ian). > > https://www.retrotechnology.com/herbs_stuff/Model4_35_Drives.pdf > (includes model 3/4 FDC pinout) > > > This includes the 300RPM jumpering for [SEVERAL VARIANTS OF] 55GFR: > http://www.oldskool.org/disk2fdi/525HDMOD.htm Got that one. But it seems to be mostly interested in making them work on XT's. > The links on it to TEAC maanuals seem to no longer be supported by Teac. The TEAC docs are still available but, again, even they seem mostly interested in what it takes to use them with XT's and AT's. > > > > To test the suspect drive, you could connect it to a PC; with DS1 > jumpered (instead of DS0), it should work as a "180K" (single sided > "360K"). a PC with a floppy controller? Wow, is that ever retro. bill From cisin at xenosoft.com Thu May 5 17:53:39 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Thu, 5 May 2022 15:53:39 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >> The Teac FD-55GFR is a 96tpi drive.?? It can replace a 55G (1.2M), or a 55F >> (720K) depending on controller, but it still has a narrow head for doing 80 >> tracks.???? It will have to be jumpered to run at 300RPM, not 360. On Thu, 5 May 2022, Bill Gunshannon via cctalk wrote: > It has a jumper that leave that up to the controller. But, the TRS-80 controller doesn't implement that signal; if the default of signal not present is 300 RPM, then it's all set, . . . > I used double sided as far back as my first Model III. Even had a > full height Tandon 80 track double sided drive. All I ever needed > was DOSPLUS or NEWDOS80. That would be the Tandon TM100-4 Although TRS-DOS didn't (until 6.0?, when TRS-DOS became rebranded LDOS), the after-market OS's supported DS and 80 track. I don't remember how you needed to tell the OS that you had DS or 80 track. But, once the OS knows, then the 55GFR, operating as a 55F, can, of course work. Do you know how to tell your CP/M about DS and 80 track? >> https://www.tim-mann.org/trs80faq.html#[19] >> Discusses the drive selects and Mentions that you can use 55GFR, but >> doesn't give the details that you need?? (300/360 RPM, double stepping, >> etc.) > The 4P has the missing pins. I never liked it and usually end out > putting in real cables and using Drive Select like it was intended. > At least until IBM won and the started making 3.5" drives without > any way to do drive select. Good. The TRS-80 and IBM special cables were specifically because they didn't think that their own staff, and customers, could set drive-select properly on the drives. >> But, more importantly, is the fault ONLY when format/verify? >> Does it still READ disks that you already have? > Haven't really tried that. Most of the disks I have are over > 20 years old. If it fails to read who's fault is it? The drive > or the disk. But, if it WORKS, . . . >> One more possibility to pay attention, (you probably already know this, so >> sorry if saying it offends you), ... >> You need to use 300 Oerstedt ("360K") diskettes.?? If you use 600 Oersted >> (1.2M) disks, they will seem to work, and then immediately, or VERY soon, >> lose their content. > Yeah, I knew about that. I still have piles of real floppies laying > around. :-) The college purchasing agent was in bed with a supplier, and kept getting us Roytype HIGH DENSITY disks for our TRS-80 lab. Even when we explicitly said not to substitute. From cisin at xenosoft.com Thu May 5 17:59:41 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Thu, 5 May 2022 15:59:41 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >> To test the suspect drive, you could connect it to a PC; with DS1 jumpered >> (instead of DS0), it should work as a "180K" (single sided "360K"). > > a PC with a floppy controller? Wow, is that ever retro. Besides FDC (especially for PCI :-), current Windoze doesn't seem to even know about single sided formats. Can they still handle "360K"? From mloewen at cpumagic.scol.pa.us Thu May 5 18:31:30 2022 From: mloewen at cpumagic.scol.pa.us (Mike Loewen) Date: Thu, 5 May 2022 19:31:30 -0400 (EDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Thu, 5 May 2022, Fred Cisin via cctalk wrote: > Although TRS-DOS didn't (until 6.0?, when TRS-DOS became rebranded LDOS), the > after-market OS's supported DS and 80 track. > I don't remember how you needed to tell the OS that you had DS or 80 track. > > But, once the OS knows, then the 55GFR, operating as a 55F, can, of course > work. > Do you know how to tell your CP/M about DS and 80 track? Montezuma Micro CP/M (which Bill mentioned in a previous post) has a CONFIG utility to tell it what kind of drive is installed (5" or 8", number of tracks, number of sides, step rate). After that, there are literally dozens of disk formats to choose from, TRS-80 and many others. Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/ From cctalk at beyondthepale.ie Thu May 5 15:44:06 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 05 May 2022 21:44:06 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> Message-ID: <01SCV00Y19UI8X0JVG@beyondthepale.ie> Hi Maciej, > > Right, my notes indicate Nichicon PL parts might be problematic too, e.g. > one at 4700uF/10V on 5V output of the H7826 PSU. > What is H7826 used in? I don't think I have any of those. > > I can confirm now Nichicon PF 47uF/35V parts to be the source of an issue > with my Bel Power. All four leaked. Thankfully I was able to fully > revive that PSU (now in 24/7 operation). > I got replacement capacitors for my POWER-ONE unit but I haven't managed to obtain a replacement IRFPE50 chopper transistor yet. I found a sort-of local supplier that lists them but they have a EUR 30 minimum order and they don't stock much other stuff I need or want :-( > > These are likely standard type parts. I've yet to come across a low > impedance axial capacitor type. I may have missed something of course. > I couldn't find any suitable axial replacements so I ended up using radials which were roughly the same height as the width of the axials. > > > > > > Heat dissipated by the cap itself under high ripple current never helps > > > and will surely speed up cap deterioration. After all its service life > > > halvens with each 10?C temperature rise even with non-faulty parts. > > > > > > > When I was shopping for replacements, I was a bit alarmed to find that > > the maximum specified "endurance" (whatever that is) I could find was > > 5000 hours. This isn't much more than a long life incandescent light bulb. > > Mind that it's at 105?C. If you keep such caps operating at 65?C (which > is still rather hot), then endurance raises to 80000h (~9 years continuous > use). > > Anyway try to chase replacements specified for at least 10000h at 105?C. > Nichicon HE/UHE and Panasonic FR seem suitable replacements for Chemi-con > SXF, Nichicon PL, surpassing old parts in terms of ESR/impedance/ripple > and dimension-wise. > When I was trying to order them, I found it hard to get anything suitable. I ended up ordering 15 (out of 16 in stock at Mouser) Panasonic FC series to do just three PSUs. > > I don't have any H7822 PSU. Your experience with the H7821 is the same > as mine though (and I still need to figure out what's wrong with one which > still doesn't drive its power-good line active after recapping). > There is a 464 or 560 Ohm resistor near the capacitor in middle of the H7821 which has been damaged by leakage in several of my PSUs. It is in series with a thermistor mounted on a heatsink and as far as I recall it is part of the fan control circuit. It might also contribute to power-good though. Other components could be damaged too or there could be goo lying under some components. > > I used > Nichicon HE P/N UHE1E182MHD as the replacement for those. There does > appear to be COVID-related shortage of this part (600 expected at Mouser > 15/03/2023, ugh!), which used to be readily available in large quantities > several years ago. However Panasonic FR P/N EEUFR1E182 is available in a > small quantity (and is better). I should grab some EEUFR1E182 before they disappear. > > I came across LXF parts in one H7826 only and they were clean, but I > chose to replace them as a precaution anyway as I've got stuck with trying > to repair a couple of broken H7826 PSUs already still not working after > cleaning the mess and replacing broken caps (mind that I'm a software > engineer with enough hassle to sort out on the software side already). > Sounds like it was better to not take a chance on them. > > I've seen leaks from SXF parts on the primary side too with the H7826, so > it is not that they only fail on the secondary side. Also it is lower > frequency ripple that's more problematic, see frequency correction factors > for ripple current in datasheets, because impedance is higher at lower > frequencies. That's an inherent property of capacitance. > That makes sense. > > > I replaced the five leaking capacitors on the upper board in my H7822, > > disconnected the input to the lower board and moved the LED connection to > > the upper board. The machine powered up nicely afterwards, the fans spun > > and the green LED came on after a short delay. However, the diagnostic > > LEDs all come on and stay on so it appears the CPU is being made aware that > > the lower board is not functioning, even though I don't need it. I should > > to do some comparisons with a H7821 and see if I can work around this. Or > > maybe I could fit some not quite to specification electrolytics from the > > junk box on the lower board, just to keep it happy? > > The symptom is exactly like with my broken H7821. Check the power-good > signal (brown wire with the H7821, possibly likewise with the H7822). It > should be driven high at the TTL level. > The wire in the same position as the brown one on a H7821 is purple on a H7822 and they both seem to have the same function. I ended up temporarily fitting a two 1000uF/25V capacitors on the lower board of my H7822 and reconnecting it to the upper board. This gave me +5.1V on the purple wire and the CPU then ran ok for test purposes. I have a VAX 4000/100A which has a Zytec Model EP 071181 power supply. The only Digital reference on it is 30-35042-01. It is the same physical form factor as the H7822. The output connectors look the same, including the wire colours except +12V is brown instead of orange and this one has an extra connector for 3.3V (which is not used for anything in the 4000/100A). The reason I mention it is there is a list of output voltages on the label: +5.1V, +12.1V, +3.3V, -12V and -9V. By a process of elimination, the -9V supply must be the grey wire (which gives me -8.2V when I put the meter on it. All the other voltages are much closer to specification). I wonder if the grey wire in the same position on the H7822 is also supposed to be -9V? When I try to measure it on my H7822, I get a negative voltage but it is wandering around -4V. In contrast, the -12V supply on the blue wire is a steady -11.99V, probably due to the 7912 regulator. The same wire as the grey on the H7822 is yellow on a H7821. I measured the voltage on a working H7821 and found a steady -0.2V which seems odd. Do you know what the white wire is for? I originally thought it might be power-good but only because the white wire on a H7816 seems to be power-good. On the 30-35042-01, it is slightly above 0V. On my H7822 it is about 5.6V and on my H7821 it is 8.8V. Regards, Peter. > > Maciej From chd at chdickman.com Thu May 5 19:44:39 2022 From: chd at chdickman.com (Charles Dickman) Date: Thu, 5 May 2022 20:44:39 -0400 Subject: PCI floppy controller In-Reply-To: References: Message-ID: On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis wrote: > On 4/21/22 18:01, Charles Dickman wrote: > > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctal > > I was at that point and looking at DP3T switches to have an external > > connection as well. DP3T switches are mess. > > You could also bring the floppy cable out to a standard DC-37 connector > on a bracket, then use a ABCD switchbox to select whatever external > DC-37-cabled floppy drive you wanted. Where would you see those DC37 connectors for external floppies? I remember them, but not exactly where. I ended up getting a DPDT switch from the hardware store. A bit of ribbon cable, some hot glue and a couple pop-rivets and it works like a charm. > --Chuck > > -chuck From cisin at xenosoft.com Thu May 5 20:05:40 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Thu, 5 May 2022 18:05:40 -0700 (PDT) Subject: PCI floppy controller In-Reply-To: References: Message-ID: > On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis wrote: >> You could also bring the floppy cable out to a standard DC-37 connector >> on a bracket, then use a ABCD switchbox to select whatever external >> DC-37-cabled floppy drive you wanted. On Thu, 5 May 2022, Charles Dickman via cctalk wrote: > Where would you see those DC37 connectors for external floppies? I remember > them, but not exactly where. > > I ended up getting a DPDT switch from the hardware store. A bit of ribbon > cable, some hot glue and a couple pop-rivets and it works like a charm. DC37 was used for the external floppy on PC/5150 and XT/5160 For the PS/2, IBM had an adapter to bring that out. DC37 was also used on the Canon CX-VDO laser printers. My Cordata used DC37, and so did my JLASER and EiconScript (Postscript and PCL) interface card, so I had ANOTHER DC37 A/B/C/D switch for my laser printer. From cclist at sydex.com Thu May 5 20:11:45 2022 From: cclist at sydex.com (Chuck Guzis) Date: Thu, 5 May 2022 18:11:45 -0700 Subject: PCI floppy controller In-Reply-To: References: Message-ID: <7af6b1c4-ca5c-5962-c6d6-f078acfd3569@sydex.com> On 5/5/22 17:44, Charles Dickman wrote: > On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis > wrote: > > On 4/21/22 18:01, Charles Dickman wrote: > > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctal > > I was at that point and looking at DP3T switches to have an external > > connection as well. DP3T switches are mess. > > You could also bring the floppy cable out to a standard DC-37 connector > on a bracket, then use a ABCD switchbox to select whatever external > DC-37-cabled floppy drive you wanted. > > > Where would you see those DC37 connectors for external floppies? I > remember them, but not exactly where.? > > I ended up getting a DPDT switch?from the hardware store. A bit of > ribbon cable, some hot glue and a couple pop-rivets and it works like a Back in the bad old days, DC37F was the common way to bring out external floppies on the ISA and MC bus. Consider, for example, the original 5150 and 5160 4-floppy controller--there's that DC37 on the bracket. All of the standard IBM external PS/2 floppy boxes used DC37-terminated cables. e.g. IBM 4869 among others. Similarly, third party controllers such as the Micro Solutions CompatiCard line and others all used DC37 connectors on the bracket. I even have brackets with a DC37 attached to a smaller PCB with the usual 34-pin header. For a motion-picture example, see https://youtu.be/ATUFjPldvcg --Chuck From dj.taylor4 at comcast.net Thu May 5 20:30:26 2022 From: dj.taylor4 at comcast.net (Douglas Taylor) Date: Thu, 5 May 2022 21:30:26 -0400 Subject: Using tu58fs with RT11 5.7 Message-ID: <676abb8e-05f7-2ec3-8a95-84b32f68de1a@comcast.net> I wanted to try using tu58fs with a RT11 system running version 5.7 to transfer files in/out. To my surprise RT11 5.7 retired the DD: device, a DD.MAC file is there, but it is unsupported. (1) How do you compile a device driver file?? How do you link and install it? (2) Has anyone done this? (3) Is anyone using tu58fs with a RT11 5.7 system? Doug From jsw at ieee.org Thu May 5 21:46:41 2022 From: jsw at ieee.org (Jerry Weiss) Date: Thu, 5 May 2022 21:46:41 -0500 Subject: Using tu58fs with RT11 5.7 In-Reply-To: <676abb8e-05f7-2ec3-8a95-84b32f68de1a@comcast.net> References: <676abb8e-05f7-2ec3-8a95-84b32f68de1a@comcast.net> Message-ID: <8f3a4b49-9261-d427-f329-1bacd2b47659@ieee.org> On 5/5/22 8:30 PM, Douglas Taylor via cctalk wrote: > I wanted to try using tu58fs with a RT11 system running version 5.7 to > transfer files in/out. > > To my surprise RT11 5.7 retired the DD: device, a DD.MAC file is > there, but it is unsupported. > > (1) How do you compile a device driver file?? How do you link and > install it? > > (2) Has anyone done this? > > (3) Is anyone using tu58fs with a RT11 5.7 system? > > Doug > If you are using one of the distributed 5.7 monitors, try taking one from an earlier & similar version like 5.6.? The 5.7 changes did not impact handlers like this IIRC. Of course if you want the build experience, check out the 5.6 device handlers manual. ? Jerry From cmhanson at eschatologist.net Thu May 5 19:37:41 2022 From: cmhanson at eschatologist.net (Chris Hanson) Date: Thu, 5 May 2022 17:37:41 -0700 Subject: Later Data General (D214/AViiON) keyboards? Message-ID: <9AECB788-ACC8-4903-B29A-BCE1FA477AAC@eschatologist.net> No, I'm not looking for old Dasher keyboards because "omg Severance." I have a couple of Data General terminals (D214) and a couple of Data General UNIX workstations (AViiON, using m88k CPU) and only one keyboard. The one that uses an 8-pin DIN connector similar to the 5-pin IBM PC XT keyboard connector?and it speaks the same protocol over the same lines, but also has a couple extra features enabled by those extra 3 pins. (I believe the part number of the DG keyboard is 6348, but I'm not positive and can't find my reference at the moment.) Does anyone have any more of the keyboards for D214 terminals or AViiON workstations that need a good home, a home which reunites them with appropriate hardware? I gather I can use XT-compatible keyboards with the AViiON systems at least, because of the compatibility I noted above, but I don't know about my terminals. -- Chris -- also always looking for anything else AViiON-related, hardware/software/docs -- and for docs for the D214 terminal too, of course From technoid6502 at gmail.com Fri May 6 11:59:53 2022 From: technoid6502 at gmail.com (Jeffrey S. Worley) Date: Fri, 06 May 2022 12:59:53 -0400 Subject: cctalk Digest, Vol 91, Issue 29 (cleaning up edge connectors) In-Reply-To: References: Message-ID: On Sat, 2022-04-30 at 12:00 -0500, cctalk-request at classiccmp.org wrote: > cleaning up edge connectors I started a religious war about 20 years ago on this list with this, but here goes: ;-) I like Pink Pearl erasers (rubbers in English). The Pink Pearl has a titch of abrasiveness, which helps remove oxide or grunge from contacts without being agressive enough to remove metal. I use a tissue dampened with a drop of wd40 and wipe the contacts. The wd encourages good contact and bars oxide formation. Best, Jeff From bill.gunshannon at hotmail.com Sat May 7 08:09:18 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Sat, 7 May 2022 09:09:18 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: I had forgotten just how much fun the TRS-80's could be. At least for the moment I am giving up on trying to get a TEAC 55GFR to work and just grabbed a par of disks from one of my COCOs to work with. I think one of the things I need to do is try to move all of my old 5.25" disks to 3.5" disks as I expect functional 5.25" drives and disks are just going to become rarer. Maybe I should try the GreaseWeazle on them and see if it can image them. On another note, at one point my 4P failed to read from a floppy. The "Cass?" prompt showed up followed by the "Memory" prompt. I'm confused. I thought the 4P didn't have any ROM in it. Where could these prompts and an apparently functioning BASIC come from? bill From cclist at sydex.com Sat May 7 10:48:33 2022 From: cclist at sydex.com (Chuck Guzis) Date: Sat, 7 May 2022 08:48:33 -0700 Subject: Anyone looking for 230V fans? Message-ID: <7d58e3cc-6e8b-ef7b-0df4-8ba6ae62e1e6@sydex.com> I don't know if this applies to any here, but I note that Electronics Goldmine has some Papst 230V 135mm fans for sale. These would be NOS: https://www.goldmine-elec-products.com/prodinfo.asp?number=G26421 FYI Chuck From cisin at xenosoft.com Sat May 7 12:48:35 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Sat, 7 May 2022 10:48:35 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Sat, 7 May 2022, Bill Gunshannon via cctalk wrote: > I had forgotten just how much fun the TRS-80's could be. > At least for the moment I am giving up on trying to get > a TEAC 55GFR to work and just grabbed a par of disks from > one of my COCOs to work with. I think one of the things > I need to do is try to move all of my old 5.25" disks to > 3.5" disks as I expect functional 5.25" drives and disks > are just going to become rarer. Maybe I should try the > GreaseWeazle on them and see if it can image them. You can image them with Dave Dunfield's 765 utilities; GreaseWeazel hardware isn't necessary. Trakcess, by Roxton Baker, is a BASIC program for TRS80 (including 3/4) that provides sector and track viewing and editing. Trivial mods are needed to it for double sided. Looking at the code of it is an extremely easy way to learn how to to controller level actions on the 3/4, if you don't already know. > On another note, at one point my 4P failed to read from > a floppy. The "Cass?" prompt showed up followed by the > "Memory" prompt. I'm confused. I thought the 4P didn't > have any ROM in it. Where could these prompts and an > apparently functioning BASIC come from? If I remember correctly (unrefreshed dynamic wet-ware), IFF you responded to those two prompts, THEN you got the BASIC, with the [cassette BASIC] version number. Did you actually GET BASIC after you responded to them?? From bill.gunshannon at hotmail.com Sat May 7 12:57:11 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Sat, 7 May 2022 13:57:11 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/7/22 13:48, Fred Cisin via cctalk wrote: > On Sat, 7 May 2022, Bill Gunshannon via cctalk wrote: >> I had forgotten just how much fun the TRS-80's could be. >> At least for the moment I am giving up on trying to get >> a TEAC 55GFR to work and just grabbed a par of disks from >> one of my COCOs to work with.? I think one of the things >> I need to do is try to move all of my old 5.25" disks to >> 3.5" disks as I expect functional 5.25" drives and disks >> are just going to become rarer.? Maybe I should try the >> GreaseWeazle on them and see if it can image them. > > You can image them with Dave Dunfield's 765 utilities; GreaseWeazel > hardware isn't necessary. Image them with what hardware? A PC or one of my TRS-80's? > > Trakcess, by Roxton Baker, is a BASIC program for TRS80 (including 3/4) > that provides sector and track viewing and editing.? Trivial mods are > needed to it for double sided.? Looking at the code of it is an > extremely easy way to learn how to to controller level actions on the > 3/4, if you don't already know. I will look for that. I used to have some nice DiskZap programs but have been unable to find any of them. At least not on a disk I can still access. :-( > >> On another note, at one point my 4P failed to read from >> a floppy.? The "Cass?" prompt showed up followed by the >> "Memory" prompt.? I'm confused.? I thought the 4P didn't >> have any ROM in it.? Where could these prompts and an >> apparently functioning BASIC come from? > > If I remember correctly (unrefreshed dynamic wet-ware), IFF you > responded to those two prompts, THEN you got the BASIC, with the > [cassette BASIC] version number.? Did you actually GET BASIC after you > responded to them?? I didn't try typing in a program but I got the "READY" prompt. I thought you had to have MODELA/III and be able to load it to get to BASIC on a 4P. I would be very surprised that while it could not boot TRSDOS it could somehow load MODELA/III from the floppy. bill From cisin at xenosoft.com Sat May 7 13:24:20 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Sat, 7 May 2022 11:24:20 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >> You can image them with Dave Dunfield's 765 utilities; GreaseWeazel >> hardware isn't necessary. On Sat, 7 May 2022, Bill Gunshannon via cctalk wrote: > Image them with what hardware? A PC or one of my TRS-80's? Yes. Either can do it. If you can find a PC with a floppy drive, "normal" FDC andBIOS, and without added OS obstacles to accessing the BIOS, then you can point Int1Eh at a table that specifies 256 byte sectors, and then you can use Int13H. (Windoze with USB floppy isn't going to work) And, of course the TRS-80 can do it. Or, you could install a 3.5" drive in your 4P and copy the disks. >> Trakcess, by Roxton Baker, is a BASIC program for TRS80 (including 3/4) >> that provides sector and track viewing and editing.? Trivial mods are >> needed to it for double sided.? Looking at the code of it is an extremely >> easy way to learn how to to controller level actions on the 3/4, if you >> don't already know. > I will look for that. I used to have some nice DiskZap programs > but have been unable to find any of them. At least not on a disk > I can still access. :-( Superzap comes with NEWDOS80, if you have an adequately complete copy handy. > I didn't try typing in a program but I got the "READY" prompt. > I thought you had to have MODELA/III and be able to load it to > get to BASIC on a 4P. I would be very surprised that while it > could not boot TRSDOS it could somehow load MODELA/III from the > floppy. INTERESTING! Unless your machine was modified, that implies that the boot process starts with copying a ROM image, and THEN it failed, . . . From spectre at floodgap.com Sat May 7 21:05:49 2022 From: spectre at floodgap.com (Cameron Kaiser) Date: Sat, 7 May 2022 19:05:49 -0700 Subject: Looking for Silent 700 Model 765 lower board Message-ID: These things must be cursed by G-d. I've landed three. Two had bad lower boards (the ones with the bubble memory and the main 9980 MCU) already. The third had a bad print mechanism. I replaced the printer mechanism, but the printhead on that was bad, so I powered it down and replaced the print head. I power it back up and its lower board suddenly stops responding too. Then, shortly after that, the upper board! (What is that circular metal can bolted down with wires exiting near the power switch? It squeals like a stuck pig.) I have plenty of bubble memory boards from these damn units, but what I need is a working lower board itself. Unless someone is experienced with board level repair and knows the typical faults on these. -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- Don't you just hate rhetorical questions? ---------------------------------- From macro at orcam.me.uk Sun May 8 06:51:51 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Sun, 8 May 2022 12:51:51 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SCV00Y19UI8X0JVG@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: Hi Peter, > > Right, my notes indicate Nichicon PL parts might be problematic too, e.g. > > one at 4700uF/10V on 5V output of the H7826 PSU. > > > > What is H7826 used in? I don't think I have any of those. DECstation 5000/1xx systems and TURBOchannel Extender boxes. Not sure if anything else. > > The symptom is exactly like with my broken H7821. Check the power-good > > signal (brown wire with the H7821, possibly likewise with the H7822). It > > should be driven high at the TTL level. > > > > The wire in the same position as the brown one on a H7821 is purple on a H7822 > and they both seem to have the same function. I ended up temporarily fitting > a two 1000uF/25V capacitors on the lower board of my H7822 and reconnecting it > to the upper board. This gave me +5.1V on the purple wire and the CPU then > ran ok for test purposes. > > I have a VAX 4000/100A which has a Zytec Model EP 071181 power supply. The > only Digital reference on it is 30-35042-01. It is the same physical form > factor as the H7822. The output connectors look the same, including the > wire colours except +12V is brown instead of orange and this one has an > extra connector for 3.3V (which is not used for anything in the 4000/100A). > The reason I mention it is there is a list of output voltages on the label: > +5.1V, +12.1V, +3.3V, -12V and -9V. By a process of elimination, the -9V > supply must be the grey wire (which gives me -8.2V when I put the meter > on it. All the other voltages are much closer to specification). > > I wonder if the grey wire in the same position on the H7822 is also supposed > to be -9V? When I try to measure it on my H7822, I get a negative voltage > but it is wandering around -4V. In contrast, the -12V supply on the blue > wire is a steady -11.99V, probably due to the 7912 regulator. The same wire > as the grey on the H7822 is yellow on a H7821. I measured the voltage on a > working H7821 and found a steady -0.2V which seems odd. > > Do you know what the white wire is for? I originally thought it might > be power-good but only because the white wire on a H7816 seems to be > power-good. On the 30-35042-01, it is slightly above 0V. On my H7822 > it is about 5.6V and on my H7821 it is 8.8V. In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage across the suspicious connections as any reference to ground may not be indicative. This voltage is also present with the H7819 PSU. It's not clear to me what it is used for. Maciej From ard.p850ug1 at gmail.com Sun May 8 09:25:54 2022 From: ard.p850ug1 at gmail.com (Tony Duell) Date: Sun, 8 May 2022 15:25:54 +0100 Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: On Sun, May 8, 2022 at 1:02 PM Maciej W. Rozycki via cctalk wrote: > In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow > wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage > across the suspicious connections as any reference to ground may not be > indicative. > > This voltage is also present with the H7819 PSU. It's not clear to me > what it is used for. It's only a guess (this is rather more modern than the DEC hardware I have), but it may be a supply for a thinwire ethernet transceiver circuit. This would be insolated from system ground of course, and I've seen something similar in an X-terminal. -tony > > Maciej From macro at orcam.me.uk Sun May 8 18:04:17 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Mon, 9 May 2022 00:04:17 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: On Sun, 8 May 2022, Tony Duell wrote: > > In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow > > wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage > > across the suspicious connections as any reference to ground may not be > > indicative. > > > > This voltage is also present with the H7819 PSU. It's not clear to me > > what it is used for. > > It's only a guess (this is rather more modern than the DEC hardware I > have), but it may be a supply for a thinwire ethernet transceiver > circuit. This would be insolated from system ground of course, and > I've seen something similar in an X-terminal. That makes sense to me. Both the VAXstation 3100 and the DECstation 3100 systems (which are among the users of the H7821 PSU) and the VAXstation 4000 system (likewise the H7819 PSU) have a built-in 10BASE2 interface. Where these PSUs are used for storage expansion boxes some voltages are of course unused. NB I have literally just recapped an H7816 PSU where I spotted a bunch of Chemi-con LXF parts starting to leak (both the DEC-usual 1800uF/25V parts and less common 2200uF/10V and 1000uF/25V ratings) as well as a pair of notorious Nichicon PL parts at 4700uF/10V (though these were clean and from the look of the closing cap a more modern variant; I've replaced them for extra safety anyway). Thankfully the PSU still was in a working condition and it was easy to get it disassembled enough to get at the parts, there was virtually no corrosion yet, and the PSU now continues working after the recap, so it was quite an easy task on this occasion. The old parts, including the leaking ones, still showed in-range values of capacitance and ESR, not unusually, which is obviously why no damage to other circuitry has been caused. Lucky me, also to think to have a look inside! Maciej From cctalk at beyondthepale.ie Mon May 9 04:55:02 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Mon, 09 May 2022 10:55:02 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: <01SCZS5O1STU8X0JVG@beyondthepale.ie> Hi Maciej, > > > > > What is H7826 used in? I don't think I have any of those. > > DECstation 5000/1xx systems and TURBOchannel Extender boxes. Not sure if > anything else. > Ok. I have VAXStation/MicroVAX and Alpha systems but no DECStations so that explains why I haven't seen them. > > > Do you know what the white wire is for? I originally thought it might > > be power-good but only because the white wire on a H7816 seems to be > > power-good. On the 30-35042-01, it is slightly above 0V. On my H7822 > > it is about 5.6V and on my H7821 it is 8.8V. > > In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow > wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage > across the suspicious connections as any reference to ground may not be > indicative. > Aha - that explains the odd and slowly varying different voltages I've found on these leads in different machines. It didn't dawn on me that they could be isolated from ground. I should have noticed that there were two adjacent leads which behaved like this. This should help clarify some of the puzzles I came across when I was trying to trace the circuit of the H7821 and H7822. Regards, Peter. > > This voltage is also present with the H7819 PSU. It's not clear to me > what it is used for. > > Maciej From cctalk at beyondthepale.ie Mon May 9 05:50:53 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Mon, 09 May 2022 11:50:53 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: <01SCZU10WOOS8X0JVG@beyondthepale.ie> Tony Duell wrote: > On Sun, May 8, 2022 at 1:02 PM Maciej W. Rozycki via cctalk > wrote: > > > In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow > > wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage > > across the suspicious connections as any reference to ground may not be > > indicative. > > > > This voltage is also present with the H7819 PSU. It's not clear to me > > what it is used for. > > It's only a guess (this is rather more modern than the DEC hardware I > have), but it may be a supply for a thinwire ethernet transceiver > circuit. This would be insolated from system ground of course, and > I've seen something similar in an X-terminal. > Hi Tony, After years of rediscovering the same failures over and over again, I finally managed to get in the habit of making notes while I am trying to diagnose faults. Now I just need to get in the habit of reading my old notes when I start to work on a new fault. I did that just now and I found that I have a MicroVAX 3100 model 76 whose internal thinwire tranceiver failed last summer. Not finding any obvious reason for the failure, I replaced it with an external tranceiver plugged into the AUI port and then forgot all about it. I should check that this floating 9V output from it's H7821 PSU is working correctly. (I wonder why it is described as -9V on the label of the 30-35042-01 PSU in my VAX 4000/100A? If it had been shown as +/-9V for example or even just plain old 9V, I would have been less inclined to assume it was referenced to ground.) Regards, Peter. > > -tony > > > > > > > Maciej From paulkoning at comcast.net Mon May 9 08:19:54 2022 From: paulkoning at comcast.net (Paul Koning) Date: Mon, 9 May 2022 09:19:54 -0400 Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: > On May 8, 2022, at 7:04 PM, Maciej W. Rozycki via cctalk wrote: > > On Sun, 8 May 2022, Tony Duell wrote: > >>> In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow >>> wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage >>> across the suspicious connections as any reference to ground may not be >>> indicative. >>> >>> This voltage is also present with the H7819 PSU. It's not clear to me >>> what it is used for. >> >> It's only a guess (this is rather more modern than the DEC hardware I >> have), but it may be a supply for a thinwire ethernet transceiver >> circuit. This would be insolated from system ground of course, and >> I've seen something similar in an X-terminal. Why would you expect a transceiver power supply to be isolated from system ground? The transceiver logic ground (via the AUI connector) is tied to the system ground. It is the coax that is isolated from the system ground, not the bulk of the transceiver circuitry. paul From ard.p850ug1 at gmail.com Mon May 9 09:46:12 2022 From: ard.p850ug1 at gmail.com (Tony Duell) Date: Mon, 9 May 2022 15:46:12 +0100 Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: On Mon, May 9, 2022 at 2:27 PM Paul Koning via cctalk wrote: > > Why would you expect a transceiver power supply to be isolated from system ground? The transceiver logic ground (via the AUI connector) is tied to the system ground. It is the coax that is isolated from the system ground, not the bulk of the transceiver circuitry. An external transceiver has an internal _isolated_ DC-DC converter and the signal lines are transformer-isolated. So the electronics is isolated from system ground. If you have an internal transceiver you either have to keep that DC-DC converter or run the electronics off an isolated output on the power supply. Note that the outer of the BNC connector is isolated from the system casing (which is grounded). In some cases those insulating bushings are actually ceramic capactors (!). -tony > > paul > From bill.gunshannon at hotmail.com Mon May 9 12:10:19 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Mon, 9 May 2022 13:10:19 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/7/22 13:48, Fred Cisin via cctalk wrote: > On Sat, 7 May 2022, Bill Gunshannon via cctalk wrote: >> >> On another note, at one point my 4P failed to read from >> a floppy.? The "Cass?" prompt showed up followed by the >> "Memory" prompt.? I'm confused.? I thought the 4P didn't >> have any ROM in it.? Where could these prompts and an >> apparently functioning BASIC come from? > > If I remember correctly (unrefreshed dynamic wet-ware), IFF you > responded to those two prompts, THEN you got the BASIC, with the > [cassette BASIC] version number.? Did you actually GET BASIC after you > responded to them?? Just took some time to duplicate it. Answered the "Cass?" prompt. Entered 0 for the "Memory" prompt. Got BASIC. Typed PRINT MEM and PRINT FRE(0). Returned 48K. Anybody have any idea where that is coming from? bill From kelly at catcorner.org Mon May 9 13:39:41 2022 From: kelly at catcorner.org (Kelly Leavitt) Date: Mon, 9 May 2022 18:39:41 +0000 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: ________________________________ From: cctalk on behalf of Bill Gunshannon via cctalk Sent: Monday, May 9, 2022 1:10 PM To: cctalk at classiccmp.org Subject: Re: The TRS-80 Journey Continues On 5/9/22 13:410 Bill via cctalk wrote: > Just took some time to duplicate it. Answered the "Cass?" prompt. > Entered 0 for the "Memory" prompt. Got BASIC. Typed PRINT MEM and > PRINT FRE(0). Returned 48K. Anybody have any idea where that is > coming from? > > bill Please explain how you duplicated it? If you had a boot floppy in the drive then is it possible that enough of the model III or 4 ROM image loaded to allow for ROM basic to exist? This might help troubleshoot https://www.trs-80.com/wordpress/zaps-patches-pokes-tips/model-4p-tipstricks/ Model 4P Tips/Tricks | Ira Goldklang's TRS-80 Revived Site TRS-80 Revived Site by Ira Goldklang's is an archive of everything related to the Tandy Radio Shack TRS-80 microcomputer lines. Site contains emulators, programs, manuals, books, patches, games, hints, discussions, questions, forums, and tons more. www.trs-80.com Kelly From bill.gunshannon at hotmail.com Mon May 9 15:45:05 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Mon, 9 May 2022 16:45:05 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/9/22 14:39, Kelly Leavitt wrote: > > > ------------------------------------------------------------------------ > *From:* cctalk on behalf of Bill > Gunshannon via cctalk > *Sent:* Monday, May 9, 2022 1:10 PM > *To:* cctalk at classiccmp.org > *Subject:* Re: The TRS-80 Journey Continues > On 5/9/22 13:410 Bill via cctalk wrote: > >> Just took some time to duplicate it.? Answered the "Cass?" prompt. >> Entered 0 for the "Memory" prompt.? Got BASIC.? Typed PRINT MEM and >> PRINT FRE(0).? Returned 48K.? Anybody have any idea where that is >> coming from? >> >> bill > Please explain how you duplicated it? If you had a boot floppy in the > drive then is it possible that enough of the model III or 4 ROM image > loaded to allow for ROM basic to exist? > I "duplicated" getting the prompts that I don;t think should be there. All I have to do is try to boot from a bad disk. ie. Hit reset while holding the "1" key with a non-bootable disk in drive 0:. > This might help troubleshoot I don't know that troubleshoot is the word to use. It's not trouble. It's just curious as I didn't even think it was possible. bill From cisin at xenosoft.com Mon May 9 16:08:24 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Mon, 9 May 2022 14:08:24 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Mon, 9 May 2022, Bill Gunshannon via cctalk wrote: > I "duplicated" getting the prompts that I don;t think should be there. > All I have to do is try to boot from a bad disk. ie. Hit reset while > holding the "1" key with a non-bootable disk in drive 0:. Sorry, to pester with irrelevant details, . . . "non-bootable disk" Do you mean a Model 4 disk without system and/or with errors? OR, will it do it with a BLANK or PC disk? >> This might help troubleshoot > I don't know that troubleshoot is the word to use. It's not trouble. > It's just curious as I didn't even think it was possible. not "troubleshoot", so much as understanding a feature and/or confirming what is "known" If it will do it with a blank disk, then the statements that it "doesn't have ROMs" are more faulty. It obviously has SOME ROMs, to start up enough to try to boot. But, this would tend towards disproving the statements that it doesn't have BASIC in ROM. And, if it has the "POKE" command, then all sorts of wondrous things become more easily available. -- Grumpy Ol' Fred cisin at xenosoft.com From jbdigriz at dragonsweb.org Mon May 9 16:59:16 2022 From: jbdigriz at dragonsweb.org (James B DiGriz) Date: Mon, 9 May 2022 17:59:16 -0400 Subject: Looking for Silent 700 Model 765 lower board In-Reply-To: References: Message-ID: <20220509175916.26793109@dragonsweb.org> On Sat, 7 May 2022 19:05:49 -0700 Cameron Kaiser via cctalk wrote: > These things must be cursed by G-d. I've landed three. Two had bad > lower boards (the ones with the bubble memory and the main 9980 MCU) > already. The third had a bad print mechanism. I replaced the printer > mechanism, but the printhead on that was bad, so I powered it down > and replaced the print head. I power it back up and its lower board > suddenly stops responding too. Then, shortly after that, the upper > board! (What is that circular metal can bolted down with wires > exiting near the power switch? It squeals like a stuck pig.) According to the manual on bitsavers, it's a power supply transformer. http://bitsavers.org/pdf/ti/terminal, page 6-57, pdf page 197, item 234. Relevant board diagrams starting at 6-38. Power supply description and diagrams beginning on 4-29 (pdf p. 107). Interesting that there are ps sections on both the upper and lower boards, which may be consistent with your symptoms. > > I have plenty of bubble memory boards from these damn units, but what > I need is a working lower board itself. Unless someone is experienced > with board level repair and knows the typical faults on these. > Never had one to work on, so I can't help you with typical faults, but I'd start by looking at the supplies, in particular the caps and diodes on the lower board. Section 4.7.1 seems potentially relevant. Good luck with it, though. Be nice if you get all 3 working. jbdigriz From bill.gunshannon at hotmail.com Mon May 9 19:16:06 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Mon, 9 May 2022 20:16:06 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/9/22 17:08, Fred Cisin via cctalk wrote: > On Mon, 9 May 2022, Bill Gunshannon via cctalk wrote: >> I "duplicated" getting the prompts that I don;t think should be there. >> All I have to do is try to boot from a bad disk.? ie. Hit reset while >> holding the "1" key with a non-bootable disk in drive 0:. > > Sorry, to pester with irrelevant details, . . . Not pestering. I appreciate you taking the time to answer my questions. > "non-bootable disk"? Do > you mean a Model 4 disk without system and/or with > errors? Yes, or a Model III disk. Or a disk I know has bad sectors on it. > OR, will it do it with a BLANK or PC disk? Didn't try either of those. Not sure I even have any. > >>> This might help troubleshoot >> I don't know that troubleshoot is the word to use.? It's not trouble. >> It's just curious as I didn't even think it was possible. > > not "troubleshoot", so much as understanding a feature and/or confirming > what is "known" > If it will do it with a blank disk, then the statements that it "doesn't > have ROMs" are more faulty. It obviously has SOME ROMs, to start up > enough to try to boot.? But, this would tend towards disproving the > statements that it doesn't have BASIC in ROM. > And, if it has the "POKE" command, then all sorts of wondrous things > become more easily available. Good point. I'm going to have to go look at the 4P Tech Ref Manual again. Maybe I am wrong it has Model III ROMS that can be switched out for 64K Ram mode. But then, what is the purpose of MODELA/III. bill From cisin at xenosoft.com Mon May 9 19:54:29 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Mon, 9 May 2022 17:54:29 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >> Sorry, to pester with irrelevant details, . . . On Mon, 9 May 2022, Bill Gunshannon via cctalk wrote: > Not pestering. I appreciate you taking the time to answer my questions. I'm enjoying "going back to those days". But, I got out of TRS80 whenthe PC was introduced. When the model4 came out, the college paid Radio Shack to upgrade the model3s into model4s, for the same price for which thay could buy bare model 4s, and let the student "lab techs" transfer over the extras from the Model 3s, which would have given model 4s PLUS bare model3s, instead of model 4s that were upgraded beaten up model3s. >> not "troubleshoot", so much as understanding a feature and/or confirming >> what is "known" >> If it will do it with a blank disk, then the statements that it "doesn't >> have ROMs" are more faulty. It obviously has SOME ROMs, to start up enough >> to try to boot.?? But, this would tend towards disproving the statements >> that it doesn't have BASIC in ROM. >> And, if it has the "POKE" command, then all sorts of wondrous things become >> more easily available. > > OR, will it do it with a BLANK or PC disk? > Didn't try either of those. Not sure I even have any. a Formatted "data" disk without system? a Coco disk? On Mon, 9 May 2022, Bill Gunshannon via cctalk wrote: > Good point. I'm going to have to go look at the 4P Tech Ref Manual > again. Maybe I am wrong it has Model III ROMS that can be switched out > for 64K Ram mode. But then, what is the purpose of MODELA/III. Well, the ROMs could be the minimal/cassette BASIC, and the disk program is the enhanced BASIC, just like IBM 5150 does. PC-DOS comes with BASICA.COM (.EXE?), which adds the enhancements to the ROM BASIC. Many/MOST OEM MS-DOS came with GW-BASIC, which was the enhanced BASIC, that did not need the ROMs. SOME OEMs, renamed GWBASIC into BASICA, so that instructions that called for BASICA would not need revision. At the time, "GW-BASIC" stood for "GeeWhiz BASIC", but later, Microsoft "forgot" what it stood for, and now Backronym it to "Graphics and Windows Beginner's All-Purpose Symbolic Instruction Code", "Greg Whitten BASIC", or "Gates/Whitten BASIC" https://www.quora.com/Why-is-the-origin-of-the-name-of-GW-BASIC-still-unclear-when-someone-could-just-ask-Bill-Gates From billdegnan at gmail.com Mon May 9 16:54:53 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Mon, 9 May 2022 17:54:53 -0400 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot Message-ID: https://philadelphia.craigslist.org/sys/d/kennett-square-vintage-computers/7480814347.html I am clearing space at the museum. I really don't want to send directly e-waste so consider making this large lot of 80's-early 2000's items for the low low price of $100 yours. If you're a HAM fest/flea market person you can profit from this haul in a matter of weeks. Bring a van. If you don't want everything, that's ok, all offers considered but you have to come to Kennett Square, PA to pick up the items. Thanks for your consideration BIll Degnan kennettclassic.com From cctalk at gtaylor.tnetconsulting.net Tue May 10 00:25:53 2022 From: cctalk at gtaylor.tnetconsulting.net (Grant Taylor) Date: Mon, 9 May 2022 23:25:53 -0600 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot In-Reply-To: References: Message-ID: On 5/9/22 3:54 PM, Bill Degnan via cctalk wrote: > https://philadelphia.craigslist.org/sys/d/kennett-square-vintage-computers/7480814347.html What are the two (identical) 1U servers that are missing the face / bezel in picture 17? They look suspiciously like a Sun 1U server I have. If they are Sun servers, there are probably people that will give you the asking price just for them. The TiVo will probably attack some attention to. Sadly, the pictures probably aren't doing this much justice. -- Grant. . . . unix || die From billdegnan at gmail.com Tue May 10 04:13:41 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Tue, 10 May 2022 05:13:41 -0400 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot In-Reply-To: References: Message-ID: Correct, they are Sun servers. I forgot they were there in the pic when I made the listing. I have been trying to find a home for them for months. Not "vintage enough" This is the classic vintage computing dilemna... all items of tech go through their worthless phase before they again become sought after. Few have the vision to collect the will-be-gems, waiting instead to be told what is "vintage". In my case I have limits to.space. I have set aside a few things I like and the rest is basically up for.grabs. To.avoid the stuff to.go to a scrapper I have set a price to ensure someone who actually wants the items B On Tue, May 10, 2022, 1:25 AM Grant Taylor via cctalk wrote: > On 5/9/22 3:54 PM, Bill Degnan via cctalk wrote: > > > https://philadelphia.craigslist.org/sys/d/kennett-square-vintage-computers/7480814347.html > > What are the two (identical) 1U servers that are missing the face / > bezel in picture 17? They look suspiciously like a Sun 1U server I have. > > If they are Sun servers, there are probably people that will give you > the asking price just for them. > > The TiVo will probably attack some attention to. > > Sadly, the pictures probably aren't doing this much justice. > > > > -- > Grant. . . . > unix || die > From g4ajq1 at gmail.com Tue May 10 09:05:13 2022 From: g4ajq1 at gmail.com (Nigel Johnson Ham) Date: Tue, 10 May 2022 10:05:13 -0400 Subject: Looking for ESDI controller for QBus Message-ID: <9c4db072-95ef-8ebb-df07-f57d9abacd8b@gmail.com> Does anybody have one they can spare? I have a DQ696 that I have to share between by 11/73 and MicroVax 2 - the Sigma RQD11 I have on the Microvax died with an internal failure and i don;t have any kind of test frame, or the space for one, to try and repair it. Cash or trade would be good. cheers, Nigel -- Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 From cctalk at gtaylor.tnetconsulting.net Tue May 10 10:58:21 2022 From: cctalk at gtaylor.tnetconsulting.net (Grant Taylor) Date: Tue, 10 May 2022 09:58:21 -0600 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot In-Reply-To: References: Message-ID: <2c37d5cd-0e6d-37e4-46f0-dc8493c36a6a@spamtrap.tnetconsulting.net> On 5/10/22 3:13 AM, Bill Degnan via cctalk wrote: > Correct, they are Sun servers. I forgot they were there in the pic > when I made the listing. I have been trying to find a home for them > for months. Not "vintage enough" Does "trying to find a home for them" mean in your collection or somebody else's caring server farm? > This is the classic vintage computing dilemna... all items of tech go > through their worthless phase before they again become sought after. > Few have the vision to collect the will-be-gems, waiting instead to > be told what is "vintage". I get it. > In my case I have limits to.space. I have set aside a few things > I like and the rest is basically up for.grabs. To.avoid the stuff > to.go to a scrapper I have set a price to ensure someone who actually > wants the items I don't know how /quickly/ you will move the lot as you've got it listed. But I do believe that /someone/ *will* /happily/ take the lot from you as it is. It seems to be a very reasonably price for what you get. It also looks like there are multiple pieces that will very likely the new server farmer will move things on to other peoples gardens. (If I can continue the metaphor.) -- Grant. . . . unix || die From billdegnan at gmail.com Tue May 10 11:12:10 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Tue, 10 May 2022 12:12:10 -0400 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot In-Reply-To: <2c37d5cd-0e6d-37e4-46f0-dc8493c36a6a@spamtrap.tnetconsulting.net> References: <2c37d5cd-0e6d-37e4-46f0-dc8493c36a6a@spamtrap.tnetconsulting.net> Message-ID: On Tue, May 10, 2022 at 11:58 AM Grant Taylor via cctalk wrote: > > On 5/10/22 3:13 AM, Bill Degnan via cctalk wrote: > > Correct, they are Sun servers. I forgot they were there in the pic > > when I made the listing. I have been trying to find a home for them > > for months. Not "vintage enough" > > Does "trying to find a home for them" mean in your collection or > somebody else's caring server farm? They're yours if you or someone can pick them up here. I have other Sun hardware, but I only can support one or two Sun's of my own for these can go to a good home if I can find one. > I don't know how /quickly/ you will move the lot as you've got it > listed. But I do believe that /someone/ *will* /happily/ take the lot > from you as it is. It seems to be a very reasonably price for what you > get. It also looks like there are multiple pieces that will very likely > the new server farmer will move things on to other peoples gardens. (If > I can continue the metaphor.) > Supposedly someone is coming today to get it all, but I can set aside the Suns if you want them. I have more than just the items I've listed in the link above that also have to go, but these I will sell one at a time and as time permits. Bill kennettclassic.com From cctalk at gtaylor.tnetconsulting.net Tue May 10 11:33:32 2022 From: cctalk at gtaylor.tnetconsulting.net (Grant Taylor) Date: Tue, 10 May 2022 10:33:32 -0600 Subject: "newer" vintage computers, parts, electronics for sale $100 LARGE lot In-Reply-To: References: <2c37d5cd-0e6d-37e4-46f0-dc8493c36a6a@spamtrap.tnetconsulting.net> Message-ID: <8431cc54-aea9-aeac-e6c4-1a020e0f9d57@spamtrap.tnetconsulting.net> On 5/10/22 10:12 AM, Bill Degnan via cctalk wrote: > They're yours if you or someone can pick them up here. Thank you for the kind offer. Unfortunately I'm multiple states away and am in no position to make such a journey. > I have other Sun hardware, but I only can support one or two Sun's > of my own for these can go to a good home if I can find one. :-) > Supposedly someone is coming today to get it all, but I can set aside > the Suns if you want them. If the person coming to get the equipment today has any interest in them, please let them take the Suns. If they have no interest, there may be others (possibly myself at some point in the future) that would be interested in buying them and having them shipped. I suspect that there are Sun specific venues; sunhelp / rescue mailing lists come to mind, that might have a higher density of Sun specific interested parties. > I have more than just the items I've listed in the link above that > also have to go, but these I will sell one at a time and as time > permits. I'd be interested in looking at such listings in the future. If nothing else, living vicariously through others. :-) -- Grant. . . . unix || die From cctalk at beyondthepale.ie Tue May 10 09:01:25 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Tue, 10 May 2022 15:01:25 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: <01SCZU10WOOS8X0JVG@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> Message-ID: <01SD1OILO3OK8X0VQA@beyondthepale.ie> Peter Coghlan wrote: > Tony Duell wrote: > > On Sun, May 8, 2022 at 1:02 PM Maciej W. Rozycki via cctalk > > wrote: > > > > > In the H7821 it's -9Vdc return pairing with -9Vdc supplied on the yellow > > > wire (an isolated circuit). Pin numbers 14 & 13. Try measuring voltage > > > across the suspicious connections as any reference to ground may not be > > > indicative. > > > > > > This voltage is also present with the H7819 PSU. It's not clear to me > > > what it is used for. > > > > It's only a guess (this is rather more modern than the DEC hardware I > > have), but it may be a supply for a thinwire ethernet transceiver > > circuit. This would be insolated from system ground of course, and > > I've seen something similar in an X-terminal. > > > > Hi Tony, > > After years of rediscovering the same failures over and over again, > I finally managed to get in the habit of making notes while I am > trying to diagnose faults. Now I just need to get in the habit of > reading my old notes when I start to work on a new fault. I did > that just now and I found that I have a MicroVAX 3100 model 76 whose > internal thinwire tranceiver failed last summer. Not finding any > obvious reason for the failure, I replaced it with an external > tranceiver plugged into the AUI port and then forgot all about it. > > I should check that this floating 9V output from it's H7821 PSU is > working correctly. > I checked it. It showed 4.4V and also seemed to be running rather hotter than the other H7821 PSUs I've been working with. I confirmed that the internal thinwire tranceiver is still not working. I swapped out the H7821 in favour of a known working H7821 which gave me 8.9V and the internal tranceiver then worked again. I put the faulty H7821 into the system that the good H7821 came from and confirmed that the internal tranceiver in that system now didn't work and the 9V supply was around 5V. With the different layout in this system, I was able to see that the rear fan in the power supply was not rotating which could account for it's higher temperature. On the offchance that this might also account for the low 9V supply, I tried unplugging the seized fan but this didn't make any difference. The 9V supply comes from a 78M09 which I hoped would be faulty because I can't make much sense of the circuit that feeds it. I pulled the same component from another older H7821 and it turned out to be a 7809 which I tried fitting in place of the 78M09 but the symptoms remained the same. Ahead of the 78M09 is another TO220 package marked D45H8 which seems to be a transistor. Then I am completely lost. I can't find the rectifier or the winding on the chopper transformer that is supposed to produce power for this part of the circuit. Making comparison resistance tests between the faulty H7821 and another one showed up some discrepancies around the 78M09 / 7809 and the D45H8 however the former were probably because of the differences between a 78M09 and a 7809 and in the latter case, the D45H8 looked reasonable when tested out of circuit. The faulty H7821 has seen orders of magnitude more usage than any of my others but it still has it's original SXF electrolytics which are not showing any signs of leakage yet that I can see without unsoldering them. It's been the right way up pretty much forever. Thanks Maciej and Tony for leading me to the cause of this issue. Another mystery (almost) solved. Regards, Peter. > > (I wonder why it is described as -9V on the label of the 30-35042-01 PSU > in my VAX 4000/100A? If it had been shown as +/-9V for example or even > just plain old 9V, I would have been less inclined to assume it was > referenced to ground.) > > Regards, > Peter. > > > > > -tony > > > > > > > > > > > > Maciej From couryhouse at aol.com Tue May 10 17:30:52 2022 From: couryhouse at aol.com (ED SHARPE) Date: Tue, 10 May 2022 22:30:52 +0000 (UTC) Subject: Who/what is Molecular Electronics Branch Electronic Technology Division References: <1883523987.1014566.1652221852814.ref@mail.yahoo.com> Message-ID: <1883523987.1014566.1652221852814@mail.yahoo.com> Who/what is Molecular Electronics Branch Electronic Technology Division thanks Ed# Sent from the all new AOL app for Android From gavin at learn.bio Tue May 10 19:02:43 2022 From: gavin at learn.bio (Gavin Scott) Date: Tue, 10 May 2022 19:02:43 -0500 Subject: Who/what is Molecular Electronics Branch Electronic Technology Division In-Reply-To: <1883523987.1014566.1652221852814@mail.yahoo.com> References: <1883523987.1014566.1652221852814.ref@mail.yahoo.com> <1883523987.1014566.1652221852814@mail.yahoo.com> Message-ID: Perhaps: "Molecular Electronics Branch, Electronic Technology Division, Air Force Avionics Laboratory, Wright-Patterson Air Force Base, Ohio." On Tue, May 10, 2022 at 5:31 PM ED SHARPE via cctalk wrote: > > Who/what is Molecular Electronics Branch Electronic Technology Division thanks Ed# > > Sent from the all new AOL app for Android From bill.gunshannon at hotmail.com Tue May 10 20:39:36 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Tue, 10 May 2022 21:39:36 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Well, I hope this doesn't sound too stupid but I have searched all the manuals I have and the web as well with no luck. How do I make a bootable floppy from a running hard disk system? Not copy an image to a floppy but build a bootable floppy disk on a real running system. I know it can be done because we had to do it all the time in the good old days. You couldn't just make repeated copies of the original because BACKUP only worked on disks of exactly the same format and we used to change physical disks all the time. 35 track, 40 track, 80 track, SS, DS, SDensity, DDensity. I thought there was a single command to make the system part and then you just added the Utilities you wanted. Does anyone have instructions on how to do this? bill From billdegnan at gmail.com Tue May 10 20:45:00 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Tue, 10 May 2022 21:45:00 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: are you running montezuma CP/M? On Tue, May 10, 2022 at 9:39 PM Bill Gunshannon via cctalk wrote: > > > > Well, I hope this doesn't sound too stupid but I have searched all > the manuals I have and the web as well with no luck. > > How do I make a bootable floppy from a running hard disk system? > Not copy an image to a floppy but build a bootable floppy disk > on a real running system. I know it can be done because we had > to do it all the time in the good old days. You couldn't just > make repeated copies of the original because BACKUP only worked > on disks of exactly the same format and we used to change physical > disks all the time. 35 track, 40 track, 80 track, SS, DS, SDensity, > DDensity. I thought there was a single command to make the system > part and then you just added the Utilities you wanted. > > Does anyone have instructions on how to do this? > > bill > From couryhouse at aol.com Tue May 10 21:08:02 2022 From: couryhouse at aol.com (ED SHARPE) Date: Wed, 11 May 2022 02:08:02 +0000 (UTC) Subject: Who/what is Molecular Electronics Branch Electronic Technology Division In-Reply-To: References: <1883523987.1014566.1652221852814.ref@mail.yahoo.com> <1883523987.1014566.1652221852814@mail.yahoo.com> Message-ID: <157668945.1046190.1652234883003@mail.yahoo.com> Were did you find that reference. Gavin? Sent from the all new AOL app for Android On Tue, May 10, 2022 at 5:02 PM, Gavin Scott wrote: Perhaps: "Molecular Electronics Branch, Electronic Technology Division, Air Force Avionics Laboratory, Wright-Patterson Air Force Base, Ohio." On Tue, May 10, 2022 at 5:31 PM ED SHARPE via cctalk wrote: > > Who/what is Molecular Electronics Branch Electronic Technology Division thanks Ed# > > Sent from the all new AOL app for Android From cisin at xenosoft.com Tue May 10 21:33:23 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Tue, 10 May 2022 19:33:23 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: > DDensity. I thought there was a single command to make the system > part and then you just added the Utilities you wanted. Was it SYSGEN? From ard.p850ug1 at gmail.com Tue May 10 22:56:58 2022 From: ard.p850ug1 at gmail.com (Tony Duell) Date: Wed, 11 May 2022 04:56:58 +0100 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: [TRS-80 Model 4P] > If it will do it with a blank disk, then the statements that it "doesn't > have ROMs" are more faulty. It obviously has SOME ROMs, to start up enough > to try to boot. But, this would tend towards disproving the statements > that it doesn't have BASIC in ROM. > And, if it has the "POKE" command, then all sorts of wondrous things > become more easily available. I don't have a 4P, only the desktop Model 4 which of course is known to have 14K of ROM containing BASIC. But I've been reading the 4P service manual which has a good description of the boot process. There is 4K of ROM in a 4P, to extend it to a larger ROM would involve major-ish hardware modifications. So I think we can discount this. However the boot process checks to see if it's likely that the Model 3 ROM image is needed and if so it will load it from disk very early on in the boot sequence. So my guess is that the disk that started all this had a valid and readable ROM image on it, this was loaded, and there was then an error loading the rest of the OS so the machine ran said BASIC. Incidentally, one feature of the 4P boot that I didn't know about is that it's possible to boot from the RS232 port. That is to download (plain binary I think) and run a program from there without a disk. -tony From ccth6600 at gmail.com Wed May 11 01:15:37 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Wed, 11 May 2022 14:15:37 +0800 Subject: Cctalk subscription disabled Message-ID: I didn't receive any cctalk messages for a few days, so I checked my Spam folder (empty) and then the archive which had several new messages I haven't seen. I then checked my cctalk membership configuration. Surprisingly "Mail delivery" was disabled. Some time ago I received a few emails from the list server about "excessive bounces" saying that I should simply reply to the email otherwise my subscription would be disabled. I replied and didn't think too much about it. This time I got no "excessive bounces" email but my subscription got disabled. I got an otherwise reliable @gmail.com email address. Does anyone else here have problems with this? Is there some way of preventing this from happening? Thanks Tom From tdk.knight at gmail.com Wed May 11 01:25:58 2022 From: tdk.knight at gmail.com (Adrian Stoness) Date: Wed, 11 May 2022 01:25:58 -0500 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: gmail is causing it On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk wrote: > I didn't receive any cctalk messages for a few days, so I checked my Spam > folder (empty) and then the archive which had several new messages I > haven't seen. I then checked my cctalk membership configuration. > Surprisingly "Mail delivery" was disabled. > > Some time ago I received a few emails from the list server about "excessive > bounces" saying that I should simply reply to the email otherwise my > subscription would be disabled. I replied and didn't think too much about > it. This time I got no "excessive bounces" email but my subscription got > disabled. > > I got an otherwise reliable @gmail.com email address. Does anyone else > here > have problems with this? Is there some way of preventing this from > happening? > > Thanks > Tom > From ccth6600 at gmail.com Wed May 11 01:34:23 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Wed, 11 May 2022 14:34:23 +0800 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: Gmail is by far the biggest email provider and works fine with other Mailman based mailing lists. How exactly is Gmail causing it and what is the work-around? Thanks Tom On Wed, May 11, 2022 at 2:26 PM Adrian Stoness wrote: > gmail is causing it > > On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk < > cctalk at classiccmp.org> wrote: > >> I didn't receive any cctalk messages for a few days, so I checked my Spam >> folder (empty) and then the archive which had several new messages I >> haven't seen. I then checked my cctalk membership configuration. >> Surprisingly "Mail delivery" was disabled. >> >> Some time ago I received a few emails from the list server about >> "excessive >> bounces" saying that I should simply reply to the email otherwise my >> subscription would be disabled. I replied and didn't think too much about >> it. This time I got no "excessive bounces" email but my subscription got >> disabled. >> >> I got an otherwise reliable @gmail.com email address. Does anyone else >> here >> have problems with this? Is there some way of preventing this from >> happening? >> >> Thanks >> Tom >> > From emu at e-bbes.com Wed May 11 02:14:07 2022 From: emu at e-bbes.com (emanuel stiebler) Date: Wed, 11 May 2022 03:14:07 -0400 Subject: Looking for ESDI controller for QBus In-Reply-To: <9c4db072-95ef-8ebb-df07-f57d9abacd8b@gmail.com> References: <9c4db072-95ef-8ebb-df07-f57d9abacd8b@gmail.com> Message-ID: <468c2fd9-b579-7aa4-422e-fdba35042ec2@e-bbes.com> On 2022-05-10 10:05, Nigel Johnson Ham via cctalk wrote: > Does anybody have one they can spare? I have a DQ696 that I have to > share between by 11/73 and MicroVax 2 - the Sigma RQD11 I have on the > Microvax died with an internal failure and i don;t have any kind of test > frame, or the space for one, to try and repair it. > > Cash or trade would be good. There is a dq696 on epay at the moment ... Never saw the cab kit before. Where was that used? External cabinets? From cc at informatik.uni-stuttgart.de Wed May 11 02:49:47 2022 From: cc at informatik.uni-stuttgart.de (Christian Corti) Date: Wed, 11 May 2022 09:49:47 +0200 (CEST) Subject: DEC H7822 power supply In-Reply-To: <01SD1OILO3OK8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> Message-ID: <5a68db0-6950-486f-1a92-e9f8fabeec9e@informatik.uni-stuttgart.de> On Tue, 10 May 2022, Peter Coghlan wrote: > Ahead of the 78M09 is another TO220 package marked D45H8 which seems to > be a transistor. Then I am completely lost. I can't find the rectifier That TO220 part would be the rectifier. It either has two legs (simple diode) or three (two-wave rectifier with presumably common cathode). Christian From cctalk at beyondthepale.ie Wed May 11 03:12:37 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Wed, 11 May 2022 09:12:37 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: <5a68db0-6950-486f-1a92-e9f8fabeec9e@informatik.uni-stuttgart.de> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> Message-ID: <01SD2GFSEVP28X0VQA@beyondthepale.ie> Christian Corti via cctalk wrote: >On Tue, 10 May 2022, Peter Coghlan wrote: > > Ahead of the 78M09 is another TO220 package marked D45H8 which seems to > > be a transistor. Then I am completely lost. I can't find the rectifier > > That TO220 part would be the rectifier. It either has two legs (simple > diode) or three (two-wave rectifier with presumably common cathode). > I thought that too at first. However, it is definately a transistor. I've made a bit more progress figuring out the circuit. There is a large torroid with three windings on it on the output side. I thought it was some sort of triple wound smoothing choke for the 5V, 12V and 9V supplies but it is not. It turns out that this is actually the source of the 9V supply. It is effectively a current transformer with two primaries. The ripple on the rectified 5V and 12V supplies gets transformed into an isolated AC source for the 9V supply. This AC goes to a simple rectifier which looks like a 1N4001 but isn't, a small choke and a smoothing capacitor. The resulting DC goes to the emitter of the D45H8 whose collector feeds the input of the 78(M)09. I haven't figured out how the base of the D45H8 is controlled yet. Regards, Peter. > > Christian > From bill.gunshannon at hotmail.com Wed May 11 05:22:42 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 06:22:42 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/10/22 21:45, Bill Degnan wrote: > are you running montezuma CP/M? > Among others. TRS-DOS,, LDOS, LS-DOS, DOSPLUS, NEWDOS. I could probably do CPM but at the moment the others are the question. bill From bill.gunshannon at hotmail.com Wed May 11 05:24:38 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 06:24:38 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/10/22 22:33, Fred Cisin wrote: > On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: >> DDensity.? I thought there was a single command to make the system >> part and then you just added the Utilities you wanted. > > > Was it SYSGEN? As near as I can tell SYSGEN only modifies a file (or two) but does not copy any files to a new location. bill From billdegnan at gmail.com Wed May 11 06:11:21 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 11 May 2022 07:11:21 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Wed, May 11, 2022, 6:24 AM Bill Gunshannon via cctalk < cctalk at classiccmp.org> wrote: > On 5/10/22 22:33, Fred Cisin wrote: > > On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: > >> DDensity. I thought there was a single command to make the system > >> part and then you just added the Utilities you wanted. > > > > > > Was it SYSGEN? > > As near as I can tell SYSGEN only modifies a file (or two) but > does not copy any files to a new location. > Each OS has its own process. PIP to copy the rest of the files if you're using CP/M Trsdos 6. (I think) FORMAT :0 BACKUP $:x :1 (SYS,INV) Where x is your hard drive letter. Depends how much is on your hard drive. If possible use a floppy to make a boot disk, less variables to manage. I have a model 4p with hard drive at the shop but the floppy disk drive needs to be replaced Bill > From billdegnan at gmail.com Wed May 11 06:14:23 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 11 May 2022 07:14:23 -0400 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: I get these every so often despite my gmail account. I believe when you're on a thread that has an email address within in it that gets flagged, all associated emails are also.flagged, based on how the reply all setting is used. My *guess* On Wed, May 11, 2022, 2:15 AM Tom Hunter via cctalk wrote: > I didn't receive any cctalk messages for a few days, so I checked my Spam > folder (empty) and then the archive which had several new messages I > haven't seen. I then checked my cctalk membership configuration. > Surprisingly "Mail delivery" was disabled. > > Some time ago I received a few emails from the list server about "excessive > bounces" saying that I should simply reply to the email otherwise my > subscription would be disabled. I replied and didn't think too much about > it. This time I got no "excessive bounces" email but my subscription got > disabled. > > I got an otherwise reliable @gmail.com email address. Does anyone else > here > have problems with this? Is there some way of preventing this from > happening? > > Thanks > Tom > From abuse at cabal.org.uk Wed May 11 06:19:19 2022 From: abuse at cabal.org.uk (Peter Corlett) Date: Wed, 11 May 2022 13:19:19 +0200 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: On Wed, May 11, 2022 at 07:14:23AM -0400, Bill Degnan via cctalk wrote: > I get these every so often despite my gmail account. I believe when you're > on a thread that has an email address within in it that gets flagged, all > associated emails are also.flagged, based on how the reply all setting is > used. My *guess* No, you get them *because* of your GMail account. GMail is a walled-garden messaging platform which only grudgingly and intermittently exchanges mail with standards-compliant Internet mail services. Google is the AOL of the 21st century. From g4ajq1 at gmail.com Wed May 11 06:22:06 2022 From: g4ajq1 at gmail.com (Nigel Johnson Ham) Date: Wed, 11 May 2022 07:22:06 -0400 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: I used to use my ieee.org email account, but it got disabled here too. So I created a gmail account, which occasionally gets the disabled message. Funnily enough, they are still sending to my ieee account even though I cannot post through it! The ieee emails are served by google. But I have no problems with any other incoming mail on either account. Methinks anti-spam settings are set too high on this list. It's good to have two accounts to get a better chance of receiving any messages form this list! cheers, Nigel Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 On 2022-05-11 07:14, Bill Degnan via cctalk wrote: > I get these every so often despite my gmail account. I believe when you're > on a thread that has an email address within in it that gets flagged, all > associated emails are also.flagged, based on how the reply all setting is > used. My *guess* > > On Wed, May 11, 2022, 2:15 AM Tom Hunter via cctalk > wrote: > >> I didn't receive any cctalk messages for a few days, so I checked my Spam >> folder (empty) and then the archive which had several new messages I >> haven't seen. I then checked my cctalk membership configuration. >> Surprisingly "Mail delivery" was disabled. >> >> Some time ago I received a few emails from the list server about "excessive >> bounces" saying that I should simply reply to the email otherwise my >> subscription would be disabled. I replied and didn't think too much about >> it. This time I got no "excessive bounces" email but my subscription got >> disabled. >> >> I got an otherwise reliable @gmail.com email address. Does anyone else >> here >> have problems with this? Is there some way of preventing this from >> happening? >> >> Thanks >> Tom >> From cctalk at beyondthepale.ie Wed May 11 06:00:55 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Wed, 11 May 2022 12:00:55 +0100 (WET-DST) Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: <01SD2MPRAVH68X0VQA@beyondthepale.ie> I recall discussion of this issue on the mailing list a number of times in the past, often involving more heat than light. I'd suggest searching the mailing list archives if this were possible. I had a quick look just now but I was only able to find this: http://www.classiccmp.org/pipermail/cctalk/2021-May/058836.html I'm pretty sure I know why it's happening but I'm also pretty sure that if I try to explain, this will result in another long fruitless argument about it. I'll just say that I agree that gmail is causing it in this case and leave it at that. Regards, Peter Coghlan. Tom Hunter via cctalk wrote: > > Gmail is by far the biggest email provider and works fine with other > Mailman based mailing lists. > How exactly is Gmail causing it and what is the work-around? > > Thanks > Tom > > On Wed, May 11, 2022 at 2:26 PM Adrian Stoness wrote: > >> gmail is causing it >> >> On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk < >> cctalk at classiccmp.org> wrote: >> >>> I didn't receive any cctalk messages for a few days, so I checked my Spam >>> folder (empty) and then the archive which had several new messages I >>> haven't seen. I then checked my cctalk membership configuration. >>> Surprisingly "Mail delivery" was disabled. >>> >>> Some time ago I received a few emails from the list server about >>> "excessive >>> bounces" saying that I should simply reply to the email otherwise my >>> subscription would be disabled. I replied and didn't think too much about >>> it. This time I got no "excessive bounces" email but my subscription got >>> disabled. >>> >>> I got an otherwise reliable @gmail.com email address. Does anyone else >>> here >>> have problems with this? Is there some way of preventing this from >>> happening? >>> >>> Thanks >>> Tom >>> >> From ccth6600 at gmail.com Wed May 11 07:05:41 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Wed, 11 May 2022 20:05:41 +0800 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: I wonder if this problem is related to DMARC anti-spam. Maybe the following would help the list admin: https://wiki.list.org/DEV/DMARC https://dmarc.org/wiki/FAQ Thanks Tom On Wed, May 11, 2022 at 2:26 PM Adrian Stoness wrote: > gmail is causing it > > On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk < > cctalk at classiccmp.org> wrote: > >> I didn't receive any cctalk messages for a few days, so I checked my Spam >> folder (empty) and then the archive which had several new messages I >> haven't seen. I then checked my cctalk membership configuration. >> Surprisingly "Mail delivery" was disabled. >> >> Some time ago I received a few emails from the list server about >> "excessive >> bounces" saying that I should simply reply to the email otherwise my >> subscription would be disabled. I replied and didn't think too much about >> it. This time I got no "excessive bounces" email but my subscription got >> disabled. >> >> I got an otherwise reliable @gmail.com email address. Does anyone else >> here >> have problems with this? Is there some way of preventing this from >> happening? >> >> Thanks >> Tom >> > From jwest at classiccmp.org Wed May 11 07:17:30 2022 From: jwest at classiccmp.org (jwest at classiccmp.org) Date: Wed, 11 May 2022 07:17:30 -0500 Subject: Cctalk subscription disabled In-Reply-To: References: Message-ID: <005301d86531$167f3d30$437db790$@classiccmp.org> Yes, Adrian is correct ? known for some time but my time/focus has been elsewhere. Addressed yesterday, should make gmail less fussy. J From: cctalk On Behalf Of Tom Hunter Sent: Wednesday, May 11, 2022 7:06 AM To: Adrian Stoness ; cctalk-owner at classiccmp.org Cc: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Cctalk subscription disabled I wonder if this problem is related to DMARC anti-spam. Maybe the following would help the list admin: https://wiki.list.org/DEV/DMARC https://dmarc.org/wiki/FAQ Thanks Tom On Wed, May 11, 2022 at 2:26 PM Adrian Stoness > wrote: gmail is causing it On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk > wrote: I didn't receive any cctalk messages for a few days, so I checked my Spam folder (empty) and then the archive which had several new messages I haven't seen. I then checked my cctalk membership configuration. Surprisingly "Mail delivery" was disabled. Some time ago I received a few emails from the list server about "excessive bounces" saying that I should simply reply to the email otherwise my subscription would be disabled. I replied and didn't think too much about it. This time I got no "excessive bounces" email but my subscription got disabled. I got an otherwise reliable @gmail.com email address. Does anyone else here have problems with this? Is there some way of preventing this from happening? Thanks Tom From bill.gunshannon at hotmail.com Wed May 11 08:08:16 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 09:08:16 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 07:11, Bill Degnan wrote: > > > On Wed, May 11, 2022, 6:24 AM Bill Gunshannon via cctalk > > wrote: > > On 5/10/22 22:33, Fred Cisin wrote: > > On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: > >> DDensity.? I thought there was a single command to make the system > >> part and then you just added the Utilities you wanted. > > > > > > Was it SYSGEN? > > As near as I can tell SYSGEN only modifies a file (or two) but > does not copy any files to a new location. > > > Each OS has its own process.? PIP to copy the rest of the files if > you're using CP/M > > Trsdos 6. (I think) > FORMAT :0 > BACKUP $:x :1 (SYS,INV) > > Where x is your hard drive letter. > > Depends how much is on your hard drive.? If possible use a floppy to > make a boot disk, less variables to manage.? I have a model 4p with hard > drive at the shop but the floppy disk drive needs to be replaced Tried it on LS-DOS 6.3.1. Was surprised it worked at all as I am used to BACKUP complaining that SOURCE and DESTINATION are not the same format. In any event, it ran till it filled up the disk and then asked another disk. Not sure what it would do with another disk but in any event, the first disk is not bootable. So my search continues. Maybe I'll try doing it again and actually give it another disk. Maybe it doesn't write the boot track until the last thing. Still think there should be a documented method for doing this. bill From billdegnan at gmail.com Wed May 11 08:32:54 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 11 May 2022 09:32:54 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: > > > > > > Each OS has its own process. PIP to copy the rest of the files if > > you're using CP/M > > > > Trsdos 6. (I think) > > FORMAT :0 > > BACKUP $:x :1 (SYS,INV) > > > > Where x is your hard drive letter. > > > > Depends how much is on your hard drive. If possible use a floppy to > > make a boot disk, less variables to manage. I have a model 4p with hard > > drive at the shop but the floppy disk drive needs to be replaced > > Tried it on LS-DOS 6.3.1. Was surprised it worked at all as I > am used to BACKUP complaining that SOURCE and DESTINATION are > not the same format. > > In any event, it ran till it filled up the disk and then asked > another disk. Not sure what it would do with another disk but > in any event, the first disk is not bootable. So my search > continues. Maybe I'll try doing it again and actually give it > another disk. Maybe it doesn't write the boot track until the > last thing. > > Still think there should be a documented method for doing this. > > bill > I looked it up, BACKUP is only for like disks, sorry I thought it might work. :-) You could try clearning your hard drive, installing only the contents of a single boot disk and then backing that up to disk using the method I suggested. That *might* work, but you'd have to re-build your hard drive again. b So From bill.gunshannon at hotmail.com Wed May 11 08:48:35 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 09:48:35 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 09:32, Bill Degnan wrote: >>> >>> >>> Each OS has its own process. PIP to copy the rest of the files if >>> you're using CP/M >>> >>> Trsdos 6. (I think) >>> FORMAT :0 >>> BACKUP $:x :1 (SYS,INV) >>> >>> Where x is your hard drive letter. >>> >>> Depends how much is on your hard drive. If possible use a floppy to >>> make a boot disk, less variables to manage. I have a model 4p with hard >>> drive at the shop but the floppy disk drive needs to be replaced >> >> Tried it on LS-DOS 6.3.1. Was surprised it worked at all as I >> am used to BACKUP complaining that SOURCE and DESTINATION are >> not the same format. >> >> In any event, it ran till it filled up the disk and then asked >> another disk. Not sure what it would do with another disk but >> in any event, the first disk is not bootable. So my search >> continues. Maybe I'll try doing it again and actually give it >> another disk. Maybe it doesn't write the boot track until the >> last thing. >> >> Still think there should be a documented method for doing this. >> >> bill >> > > I looked it up, BACKUP is only for like disks, sorry I thought it > might work. :-) Interestingly, it does work from the hard disk to the floppy. The second (and I assume subsequent disks) is a data disk and doesn't boot. The first disk tries to boot but my guess is it has a hard disk boot block which won;t work from a floppy. :-) > > You could try clearning your hard drive, installing only the contents > of a single boot disk and then backing that up to disk using the > method I suggested. That *might* work, but you'd have to re-build > your hard drive again. Based on the results of my last attempt, I doubt it would work. Looks like there is a need to figure out how to install a boot block and what files need to be copied to make usable floppies for all the OSes. Yet another task to work on. I still can't believe there is no documented way to do this already!! bill From billdegnan at gmail.com Wed May 11 09:18:37 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 11 May 2022 10:18:37 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: > > Based on the results of my last attempt, I doubt it would work. > Looks like there is a need to figure out how to install a boot > block and what files need to be copied to make usable floppies > for all the OSes. Yet another task to work on. > > I still can't believe there is no documented way to do this > already!! > > bill > > >From what I read, there is no easy way to make a bootable disk from a hard drive that I know of. You need to make a backup diskette to diskette. Because of this, SuperDisk software and SuperZap utilities were sold to make these kinds of tasks practical. https://www.tim-mann.org/trs80/ https://www.tim-mann.org/trs80/Su4cmd.zip Bill From bitwiz at 12bitsbest.com Wed May 11 09:34:43 2022 From: bitwiz at 12bitsbest.com (Mike Katz) Date: Wed, 11 May 2022 09:34:43 -0500 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> I don't know about TRS-DOS but a lot of early floppy disk format programs had an option to make the formatted disk bootable or not. This would copy the bootloader to the appropriate location on the floppy, copy the OS to the floppy and update any necessary pointers to the OS on the floppy. Usually a ROM bootloader would load a known sector (usually Track 0, Sector 0) and execute the code from that sector.? That code would then get the address of the Operating System from the disk (either in a fixed location on disk or a fixed location in the directory) and load the OS. On 5/11/2022 9:18 AM, Bill Degnan via cctalk wrote: > >> Based on the results of my last attempt, I doubt it would work. >> Looks like there is a need to figure out how to install a boot >> block and what files need to be copied to make usable floppies >> for all the OSes. Yet another task to work on. >> >> I still can't believe there is no documented way to do this >> already!! >> >> bill >> >> > >From what I read, there is no easy way to make a bootable disk from a > hard drive that I know of. You need to make a backup diskette to > diskette. Because of this, SuperDisk software and SuperZap utilities > were sold to make these kinds of tasks practical. > > https://www.tim-mann.org/trs80/ > https://www.tim-mann.org/trs80/Su4cmd.zip > > Bill From anders.k.nelson at gmail.com Wed May 11 10:09:19 2022 From: anders.k.nelson at gmail.com (Anders Nelson) Date: Wed, 11 May 2022 11:09:19 -0400 Subject: Cctalk subscription disabled In-Reply-To: <005301d86531$167f3d30$437db790$@classiccmp.org> References: <005301d86531$167f3d30$437db790$@classiccmp.org> Message-ID: Yes I've been getting the same "excessive bounces" emails as well! -- Anders Nelson +1 (517) 775-6129 www.erogear.com On Wed, May 11, 2022 at 8:17 AM jwest--- via cctalk wrote: > Yes, Adrian is correct ? known for some time but my time/focus has been > elsewhere. Addressed yesterday, should make gmail less fussy. > > > > J > > > > From: cctalk On Behalf Of Tom Hunter > Sent: Wednesday, May 11, 2022 7:06 AM > To: Adrian Stoness ; cctalk-owner at classiccmp.org > Cc: General Discussion: On-Topic and Off-Topic Posts < > cctalk at classiccmp.org> > Subject: Re: Cctalk subscription disabled > > > > I wonder if this problem is related to DMARC anti-spam. > > Maybe the following would help the list admin: > > > > https://wiki.list.org/DEV/DMARC > > https://dmarc.org/wiki/FAQ > > > > Thanks > > Tom > > > > On Wed, May 11, 2022 at 2:26 PM Adrian Stoness > wrote: > > gmail is causing it > > > > On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk < > cctalk at classiccmp.org > wrote: > > I didn't receive any cctalk messages for a few days, so I checked my Spam > folder (empty) and then the archive which had several new messages I > haven't seen. I then checked my cctalk membership configuration. > Surprisingly "Mail delivery" was disabled. > > Some time ago I received a few emails from the list server about "excessive > bounces" saying that I should simply reply to the email otherwise my > subscription would be disabled. I replied and didn't think too much about > it. This time I got no "excessive bounces" email but my subscription got > disabled. > > I got an otherwise reliable @gmail.com email address. > Does anyone else here > have problems with this? Is there some way of preventing this from > happening? > > Thanks > Tom > > From ccth6600 at gmail.com Wed May 11 10:28:16 2022 From: ccth6600 at gmail.com (Tom Hunter) Date: Wed, 11 May 2022 23:28:16 +0800 Subject: Cctalk subscription disabled In-Reply-To: References: <005301d86531$167f3d30$437db790$@classiccmp.org> Message-ID: Strangely I did not receive jwest's reply quoted by Anders Nelson in my Gmail account. It is quoted in Anders' email and I see the original message from jwest in the cctalk archive. My Gmail Spam folder is empty. What is going on? It is as if classiccmp.org is blacklisted by Gmail. Tom Hunter On Wed, May 11, 2022 at 11:09 PM Anders Nelson wrote: > Yes I've been getting the same "excessive bounces" emails as well! > -- > Anders Nelson > > +1 (517) 775-6129 > > www.erogear.com > > > On Wed, May 11, 2022 at 8:17 AM jwest--- via cctalk > wrote: > >> Yes, Adrian is correct ? known for some time but my time/focus has been >> elsewhere. Addressed yesterday, should make gmail less fussy. >> >> >> >> J >> >> >> >> From: cctalk On Behalf Of Tom Hunter >> Sent: Wednesday, May 11, 2022 7:06 AM >> To: Adrian Stoness ; cctalk-owner at classiccmp.org >> Cc: General Discussion: On-Topic and Off-Topic Posts < >> cctalk at classiccmp.org> >> Subject: Re: Cctalk subscription disabled >> >> >> >> I wonder if this problem is related to DMARC anti-spam. >> >> Maybe the following would help the list admin: >> >> >> >> https://wiki.list.org/DEV/DMARC >> >> https://dmarc.org/wiki/FAQ >> >> >> >> Thanks >> >> Tom >> >> >> >> On Wed, May 11, 2022 at 2:26 PM Adrian Stoness > > wrote: >> >> gmail is causing it >> >> >> >> On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk < >> cctalk at classiccmp.org > wrote: >> >> I didn't receive any cctalk messages for a few days, so I checked my Spam >> folder (empty) and then the archive which had several new messages I >> haven't seen. I then checked my cctalk membership configuration. >> Surprisingly "Mail delivery" was disabled. >> >> Some time ago I received a few emails from the list server about >> "excessive >> bounces" saying that I should simply reply to the email otherwise my >> subscription would be disabled. I replied and didn't think too much about >> it. This time I got no "excessive bounces" email but my subscription got >> disabled. >> >> I got an otherwise reliable @gmail.com email >> address. Does anyone else here >> have problems with this? Is there some way of preventing this from >> happening? >> >> Thanks >> Tom >> >> From bill.gunshannon at hotmail.com Wed May 11 13:13:25 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 14:13:25 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: On 5/11/22 13:40, Wayne S wrote: > There?s some utube videos on making bootable floppies. Maybe one of them > will give you some ideas. > Here?s one that looks promising. > > https://m.youtube.com/watch?v=XoxpnZ__w5Q > That's a Tandy 2000. Not a TRS-80 at all and it was never called that by Radio Shack. There are hundreds of YouTube videos on making MSDOS bootable floppies. Being as all it really took was the format command I don't understand all the interest. Nothing I could find on YouTube about real TRS-80's but then I would expect nothing more from that waste of time. bill From bill.gunshannon at hotmail.com Wed May 11 13:16:37 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 14:16:37 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: So, the bad news is no way found so far to make bootable floppies. Maybe not bad news as it gives me another fun project to work on. Further good news, however, is that I have revived my M3SE, MISE and 2 FreHD's so I now have hard disks for pretty much all my old systems. Just have to build up the Hard Disks with the software I need to play with. bill From r_a_feldman at hotmail.com Wed May 11 13:51:51 2022 From: r_a_feldman at hotmail.com (Robert Feldman) Date: Wed, 11 May 2022 18:51:51 +0000 Subject: The TRS-80 Journey Continues Message-ID: > >Date: Wed, 11 May 2022 06:24:38 -0400 >From: Bill Gunshannon >To: Fred Cisin , "General Discussion: On-Topic and Off-Topic Posts" >Subject: Re: The TRS-80 Journey Continues > >>On 5/10/22 22:33, Fred Cisin wrote: >>On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: >>DDensity.? I thought there was a single command to make the system >>part and then you just added the Utilities you wanted. >> >> >>Was it SYSGEN? > >As near as I can tell SYSGEN only modifies a file (or two) but >does not copy any files to a new location. > >Bill > No, SYSGEN is the CP/M command to initialize a blank, formatted disk with the CP/M system: ?The SYSGEN transient command allows generation of an initialized disk containing the CP/M operating system. The SYSGEN program prompts the console for commands by interacting as shown...? (From http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch1.htm#Section_1.6.6). SYSGEN puts the CP/M system files on a reserved (not visible) area of the disk. It is a separate program, not a built-in command. On the Osborne (which I used), CP/M was 4KB in size. You can use then use PIP to copy the other, visible files. Bob From bill.gunshannon at hotmail.com Wed May 11 13:59:53 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 14:59:53 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 14:51, Robert Feldman via cctalk wrote: >> >> Date: Wed, 11 May 2022 06:24:38 -0400 >> From: Bill Gunshannon >> To: Fred Cisin , "General Discussion: On-Topic and > Off-Topic Posts" >> Subject: Re: The TRS-80 Journey Continues >> >>> On 5/10/22 22:33, Fred Cisin wrote: >>> On Tue, 10 May 2022, Bill Gunshannon via cctalk wrote: >>> DDensity.? I thought there was a single command to make the system >>> part and then you just added the Utilities you wanted. >>> >>> >>> Was it SYSGEN? >> >> As near as I can tell SYSGEN only modifies a file (or two) but >> does not copy any files to a new location. >> >> Bill >> > > No, SYSGEN is the CP/M command to initialize a blank, formatted disk with the CP/M system: > > ?The SYSGEN transient command allows generation of an initialized disk containing the CP/M operating system. The SYSGEN program prompts the console for commands by interacting as shown...? (From http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch1.htm#Section_1.6.6). > > SYSGEN puts the CP/M system files on a reserved (not visible) area of the disk. It is a separate program, not a built-in command. On the Osborne (which I used), CP/M was 4KB in size. You can use then use PIP to copy the other, visible files. > Seems a bunch of crossed wires. SYSGEN is also a command on LDOS, LS-DOS, versions of TRS-DOS (that were actually versions of LDOS or LS-DOS) but with a totally different function. I didn't now the command off the top of my head but I did know that making bootable floppies under CP/M was not difficult. Just like moving it to allow for different memory maps. Something else that none of the other TRS-80 OSes can do. bill From cisin at xenosoft.com Wed May 11 15:23:13 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Wed, 11 May 2022 13:23:13 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: >> are you running montezuma CP/M? On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: > Among others. > TRS-DOS,, LDOS, LS-DOS, DOSPLUS, NEWDOS. > I could probably do CPM but at the moment the others are the > question. I, also, thought that you were asking for Montezuma Micro when I mentioned SYSGEN. For the TRSDOS derivatives, you may need to locate a floppy boot disk for each, remove all "unnecessary" programs from a copy of it, and then BACKUP lots of copies. From cisin at xenosoft.com Wed May 11 15:36:12 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Wed, 11 May 2022 13:36:12 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: >> https://m.youtube.com/watch?v=XoxpnZ__w5Q On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: > That's a Tandy 2000. Not a TRS-80 at all and it was never called that > by Radio Shack. There are hundreds of YouTube videos on making MSDOS > bootable floppies. Being as all it really took was the format command > I don't understand all the interest. Because it is hard to make a video of something difficult, but easy to make a video saying to put /S after FORMAT. From dave.g4ugm at gmail.com Wed May 11 16:06:46 2022 From: dave.g4ugm at gmail.com (dave.g4ugm at gmail.com) Date: Wed, 11 May 2022 22:06:46 +0100 Subject: Cctalk subscription disabled In-Reply-To: <005301d86531$167f3d30$437db790$@classiccmp.org> References: <005301d86531$167f3d30$437db790$@classiccmp.org> Message-ID: <047f01d8657b$067f79f0$137e6dd0$@gmail.com> Jay, Thanks for that, I hope its fixed, Dave G4UGM > -----Original Message----- > From: cctalk On Behalf Of jwest--- via > cctalk > Sent: 11 May 2022 13:18 > To: 'Tom Hunter' ; 'Adrian Stoness' > ; cctalk-owner at classiccmp.org > Cc: 'General Discussion: On-Topic and Off-Topic Posts' > > Subject: RE: Cctalk subscription disabled > > Yes, Adrian is correct ? known for some time but my time/focus has been > elsewhere. Addressed yesterday, should make gmail less fussy. > > > > J > > > > From: cctalk On Behalf Of Tom Hunter > Sent: Wednesday, May 11, 2022 7:06 AM > To: Adrian Stoness ; cctalk-owner at classiccmp.org > Cc: General Discussion: On-Topic and Off-Topic Posts > > Subject: Re: Cctalk subscription disabled > > > > I wonder if this problem is related to DMARC anti-spam. > > Maybe the following would help the list admin: > > > > https://wiki.list.org/DEV/DMARC > > https://dmarc.org/wiki/FAQ > > > > Thanks > > Tom > > > > On Wed, May 11, 2022 at 2:26 PM Adrian Stoness > wrote: > > gmail is causing it > > > > On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk > > wrote: > > I didn't receive any cctalk messages for a few days, so I checked my Spam > folder (empty) and then the archive which had several new messages I > haven't seen. I then checked my cctalk membership configuration. > Surprisingly "Mail delivery" was disabled. > > Some time ago I received a few emails from the list server about "excessive > bounces" saying that I should simply reply to the email otherwise my > subscription would be disabled. I replied and didn't think too much about it. > This time I got no "excessive bounces" email but my subscription got > disabled. > > I got an otherwise reliable @gmail.com email address. > Does anyone else here have problems with this? Is there some way of > preventing this from happening? > > Thanks > Tom From bill.gunshannon at hotmail.com Wed May 11 16:24:11 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 17:24:11 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 16:23, Fred Cisin via cctalk wrote: >>> are you running montezuma CP/M? > > On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: >> Among others. >> TRS-DOS,, LDOS, LS-DOS, DOSPLUS, NEWDOS. >> I could probably do CPM but at the moment the others are the >> question. > > I, also, thought that you were asking for Montezuma Micro when I > mentioned SYSGEN. > > For the TRSDOS derivatives, you may need to locate a floppy boot disk > for each, remove all "unnecessary" programs from a copy of it, and then > BACKUP lots of copies. > That appears to be the way it is right now. Wish I remembered how we took NEWDOS80 from a 40 Track SSDD floppy and moved it to an 80 Track DSDD floppy (which I had on my Model III back in the 80's). But a project might be to fix that. Might require making a copy of the boot block for all the different OSes I decide to play with but, what the heck, we just do this for fun any way, right? bill From bill.gunshannon at hotmail.com Wed May 11 17:43:00 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 18:43:00 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 17:54, Wayne S wrote: > Have you seen this post? > > https://www.nightfallcrew.com/15/04/2012/tandy-radio-shack-trs-80-model-4p-dos-boot-disk/ > I've seen that. Again, that is not building a boot disk that is taking an image from somewhere on the web and using a PC with pretty much non-existent hardware to copy the image to a physical disk. No TRS-80 involved at all. bill From bill.gunshannon at hotmail.com Wed May 11 18:04:42 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 19:04:42 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: On 5/11/22 10:34, Mike Katz wrote: > I don't know about TRS-DOS but a lot of early floppy disk format > programs had an option to make the formatted disk bootable or not. This > would copy the bootloader to the appropriate location on the floppy, > copy the OS to the floppy and update any necessary pointers to the OS on > the floppy. That's what i thought, too. But I have been unable to find anything like that in any of the documentation I still have. I did find that the SYSGEN Utility under DOSPLUS may be able to that. But it may only work from floppy to floppy and not when the system is booted from a hard disk. > > Usually a ROM bootloader would load a known sector (usually Track 0, > Sector 0) and execute the code from that sector.? That code would then > get the address of the Operating System from the disk (either in a fixed > location on disk or a fixed location in the directory) and load the OS. > That's the way I have always known it to be. Thus why I said if I work on a project to build boot floppies from hard disk systems I will have to have a collection of BOOT Code for the various OSes and know how they use it. I guess the first thing I will need is a program to read raw data from a floppy and another to write raw data to a floppy. This looks like a perfect job for PL/M. :-) bill From cctalk at beyondthepale.ie Wed May 11 18:02:20 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 00:02:20 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> Message-ID: <01SD3BDFJWHI8X0VQA@beyondthepale.ie> It's hard to come up with suitable terms for this sort of stuff that convey the meaning of what is going on. I struggled with it for a while and that was what I ended up with. With the strict meaning of DC and AC being direct current and alternating current and given that we are often talking about voltages rather than currents, meanings are already getting stretched. Besides, what's direct about it? Maybe it would be more accurate to use terms like steady voltage and alternating voltage? Alternating doesn't seem like that good a term either. To me it suggests some sort of square wave switching very rapidly between one extreme and another, not a nice lazy sine wave which is the normally accepted meaning. Given the normal usage that has evolved for the terms DC and AC rather than their dictionary definitions, I would suggest that the current that gets passed by a rectifier has both a DC component and an AC component. When this mixture is fed into a transformer primary as in this case, the DC component does not pass through from the primary to the secondary but the AC component does. Transformers only work on AC, right? Or maybe it could equally be said that a transformer can be used to convert pulsed DC to AC? (The transformer has to be kinda special to avoid the core getting saturated by the large DC current (What's a "direct current current"?) flowing through the primaries...) Anyway, the good news is that I think I have found the source of the problem. One of the capacitors used to filter the (DC?, pulsed DC?, rippled DC?, biased AC?) supply to the 9V regulator is marked 330uF/25V. It reads 6uF on the capacitance range on my multimeter. This can't be helping the cause. It's not showing any signs of leakage but it's got a brown sleeve and the same logo as the nasty, leaky SXF capacitors but it is marked KME. (I said there was only one capacitor in the filter in a previous posting. Originally I managed to spot a little 10uF/100V capacitor but somehow failed to notice the chubbier 330uF/25V capacitor completing a PI filter with a small choke...) Regards, Peter Coghlan. Sent from my DEC Alphaserver 800 Wayne S wrote: > > ? The ripple on the rectified 5V and 12V supplies gets transformed into an > isolated AC source for the 9V supply. ? > Shouldn?t that be ?pulsed DC? instead of ?AC? as rectification > changes AC to DC ? > > > Sent from my iPhone > >> On May 11, 2022, at 01:36, Peter Coghlan via cctalk wrote: >> >> The ripple on the rectified 5V and 12V supplies gets transformed into an >> isolated AC source for the 9V supply. > From cisin at xenosoft.com Wed May 11 18:51:04 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Wed, 11 May 2022 16:51:04 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: > That's the way I have always known it to be. Thus why I said if > I work on a project to build boot floppies from hard disk systems > I will have to have a collection of BOOT Code for the various OSes > and know how they use it. I guess the first thing I will need is > a program to read raw data from a floppy and another to write raw > data to a floppy. This looks like a perfect job for PL/M. :-) In the meantime (as a proof of concept?), you can manually read and write sectors with SUPERZAP ? and create a program in PL/M that makes boot floppies. From bill.gunshannon at hotmail.com Wed May 11 19:11:25 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 20:11:25 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: On 5/11/22 19:51, Fred Cisin via cctalk wrote: > On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: >> That's the way I have always known it to be. Thus why I said if >> I work on a project to build boot floppies from hard disk systems >> I will have to have a collection of BOOT Code for the various OSes >> and know how they use it.? I guess the first thing I will need is >> a program to read raw data from a floppy and another to write raw >> data to a floppy.? This looks like a perfect job for PL/M.? :-) > > In the meantime (as a proof of concept?), you can manually read and > write sectors with SUPERZAP? ? Wow, SuperZAP. Time do build a System with NEWDOS80. :-) > and create a program in PL/M that makes boot floppies. Well, at least to write the boot code to the disk. Still have to figure out what files need to be there for each OS and come up with a way to copy them. Hopefully as automated as possible. But not right now as tomorrow I leave for Walter Reed Hospital. bill From macro at orcam.me.uk Wed May 11 20:00:24 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Thu, 12 May 2022 02:00:24 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SD3BDFJWHI8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: On Thu, 12 May 2022, Peter Coghlan via cctalk wrote: > Anyway, the good news is that I think I have found the source of the > problem. One of the capacitors used to filter the (DC?, pulsed DC?, > rippled DC?, biased AC?) supply to the 9V regulator is marked 330uF/25V. > It reads 6uF on the capacitance range on my multimeter. This can't be > helping the cause. It's not showing any signs of leakage but it's got > a brown sleeve and the same logo as the nasty, leaky SXF capacitors but > it is marked KME. (I said there was only one capacitor in the filter > in a previous posting. Originally I managed to spot a little 10uF/100V > capacitor but somehow failed to notice the chubbier 330uF/25V capacitor > completing a PI filter with a small choke...) Likely just a general purpose capacitor. I only have 2 330uF/25V 85?C Nichicon SE parts listed for the H7821 (and I have a note about one PSU of this kind having a 220uF/35V part in place of one of those too). Also no 100V parts at all, but 4 10uF/35V 105?C parts, either Teapo SE or Daewoo RS. Teapo SE and Chemi-con KME series are standard general purpose parts and given the low temperature rating Nichicon SE are likely such as well. I guess especially for standard capacitors factories ordered whatever was readily available whereas with the high-ripple low-impedance/ESR parts the choice was much more limited. Maciej From paulkoning at comcast.net Wed May 11 20:04:15 2022 From: paulkoning at comcast.net (Paul Koning) Date: Wed, 11 May 2022 21:04:15 -0400 Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <2828A7E5-5E31-47AA-A67C-D17AF97E1457@comcast.net> > On May 11, 2022, at 9:00 PM, Maciej W. Rozycki via cctalk wrote: > > ... > I guess especially for standard capacitors factories ordered whatever was > readily available whereas with the high-ripple low-impedance/ESR parts the > choice was much more limited. I wonder if nowadays a good replacement for the case where low ESR is needed would be a big ceramic capacitor. Unlike the old days those now can be had in many-?F capacitances. paul From cisin at xenosoft.com Wed May 11 20:05:56 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Wed, 11 May 2022 18:05:56 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: >> In the meantime (as a proof of concept?), you can manually read and write >> sectors with SUPERZAP? ? On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: > Wow, SuperZAP. Time do build a System with NEWDOS80. :-) Well, it's a good one to have. There are lots of alternatives to SUPERZAP, including TRAKCESS, whose source code will answer a few questions about TRS80 disk access. Allen Gelder (Superstep) once told me that TRAKCESS had been Roixton Baker's major assembly language learning project. SuperUtility and, TRSCROSS by Mike Gingel does some disk format conversion. > >> and create a program in PL/M that makes boot floppies. > Well, at least to write the boot code to the disk. Still have > to figure out what files need to be there for each OS and come > up with a way to copy them. Hopefully as automated as possible. > > But not right now as tomorrow I leave for Walter Reed Hospital. Yikes. I hope that that's as a doctor/consultant/visitor, not for treatment. From billdegnan at gmail.com Wed May 11 20:07:36 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 11 May 2022 21:07:36 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: > >>Was it SYSGEN? > > > >As near as I can tell SYSGEN only modifies a file (or two) but > >does not copy any files to a new location. > > > >Bill > > > > No, SYSGEN is the CP/M command to initialize a blank, formatted disk with the CP/M system: > > ?The SYSGEN transient command allows generation of an initialized disk containing the CP/M operating system. The SYSGEN program prompts the console for commands by interacting as shown...? (From http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch1.htm#Section_1.6.6). > > SYSGEN puts the CP/M system files on a reserved (not visible) area of the disk. It is a separate program, not a built-in command. On the Osborne (which I used), CP/M was 4KB in size. You can use then use PIP to copy the other, visible files. > > Bob > This is a very good point. Bill what OS is your hard drive? I am not sure if you need the disk you're creating to match the hard drive or not, but it will make life a lot easier if they are the same. LDOS, NEWDOS, TRSDOS, CP/M are all very different and only NEWDOS attempts at being compatible with other OS's. Bill From bill.gunshannon at hotmail.com Wed May 11 20:13:48 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 21:13:48 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: <4deef819-18d7-b808-b667-2b201e9fd6fc@12bitsbest.com> Message-ID: On 5/11/22 21:05, Fred Cisin via cctalk wrote: >>> In the meantime (as a proof of concept?), you can manually read and >>> write sectors with SUPERZAP? ? > > On Wed, 11 May 2022, Bill Gunshannon via cctalk wrote: >> Wow, SuperZAP.? Time do build a System with NEWDOS80.? :-) > > Well, it's a good one to have. > There are lots of alternatives to SUPERZAP, including TRAKCESS, whose > source code will answer a few questions about TRS80 disk access. > Allen Gelder (Superstep) once told me that TRAKCESS had been Roixton > Baker's major assembly language learning project. > SuperUtility > and, TRSCROSS by Mike Gingel does some disk format conversion. I'll look up some of these. I wrote a diskzap of my own (didn't we all?) many moons ago but I don't still have a copy or remember anything about how I did it. But SuperZAP came with NEWDOS80 and I probably used it the most. Usually for removing passwords. :-) > > >> >>> and create a program in PL/M that makes boot floppies. >> Well, at least to write the boot code to the disk.? Still have >> to figure out what files need to be there for each OS and come >> up with a way to copy them.? Hopefully as automated as possible. >> >> But not right now as tomorrow I leave for Walter Reed Hospital. > > Yikes. > I hope that that's as a doctor/consultant/visitor, not for treatment. Nope, the consultations are over. Monday they rebuild my knee. I wanted the bionic one but I didn't have the 6 Million Dollars. At least there I will get a rebuild and not the hack job replacement that is the norm where I live. bill From bill.gunshannon at hotmail.com Wed May 11 20:17:53 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 11 May 2022 21:17:53 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On 5/11/22 21:07, Bill Degnan via cctalk wrote: >>>> Was it SYSGEN? >>> >>> As near as I can tell SYSGEN only modifies a file (or two) but >>> does not copy any files to a new location. >>> >>> Bill >>> >> >> No, SYSGEN is the CP/M command to initialize a blank, formatted disk with the CP/M system: >> >> ?The SYSGEN transient command allows generation of an initialized disk containing the CP/M operating system. The SYSGEN program prompts the console for commands by interacting as shown...? (From http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch1.htm#Section_1.6.6). >> >> SYSGEN puts the CP/M system files on a reserved (not visible) area of the disk. It is a separate program, not a built-in command. On the Osborne (which I used), CP/M was 4KB in size. You can use then use PIP to copy the other, visible files. >> >> Bob >> > > This is a very good point. Bill what OS is your hard drive? I am not > sure if you need the disk you're creating to match the hard drive or > not, but it will make life a lot easier if they are the same. LDOS, > NEWDOS, TRSDOS, CP/M are all very different and only NEWDOS attempts > at being compatible with other OS's. Because my "hard disks" are FreHD, MISE and M3SE I have multiple operating systems. I plan to work with CP/M, TRSDOS, LDOS, LS-DOS, DosPlus and NEWDOS80. They were all the ones I worked with back when the TRS-80 was still new and I actually still have copies of disks and documentation for most of it. CP/M and DosPlus were my favorites. bill From 13gw13 at gmail.com Wed May 11 16:24:50 2022 From: 13gw13 at gmail.com (Grzegorz) Date: Wed, 11 May 2022 23:24:50 +0200 Subject: Tri-Data Cartrifile parts/interfaces/tapes? Message-ID: Hello Jim. I read on the forum that you have a Tri-Data Cartrifile cartridge. I'm looking for them for my cassette collection, but they're nowhere. I am a collector of tapes, cassettes and disks ... I have a question. Can you sell me one cartridge? Best regards Greg. From cc at informatik.uni-stuttgart.de Thu May 12 03:40:17 2022 From: cc at informatik.uni-stuttgart.de (Christian Corti) Date: Thu, 12 May 2022 10:40:17 +0200 (CEST) Subject: DEC H7822 power supply In-Reply-To: <01SD3BDFJWHI8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <4e87131-de8-a66-fb7-f138748da036@informatik.uni-stuttgart.de> On Thu, 12 May 2022, Peter Coghlan wrote: > about it? Maybe it would be more accurate to use terms like steady voltage > and alternating voltage? Alternating doesn't seem like that good a term In German it's exactly like you suggest it. We say "Gleichspannung" (= constant/steady voltage) and "Wechselspannung" (=alternating voltage) I also hate the English/American expression "inverter" for voltage converters, because really nothing is being inverted in any way. But hey, they still have inches and feet and ounzes (be they fluid or solid) and gallons, so what can I expect? ;-)))) Christian From jon at jonworld.com Thu May 12 05:22:06 2022 From: jon at jonworld.com (Jonathan Katz) Date: Thu, 12 May 2022 11:22:06 +0100 Subject: Who/what is Molecular Electronics Branch Electronic Technology Division In-Reply-To: <157668945.1046190.1652234883003@mail.yahoo.com> References: <1883523987.1014566.1652221852814.ref@mail.yahoo.com> <1883523987.1014566.1652221852814@mail.yahoo.com> <157668945.1046190.1652234883003@mail.yahoo.com> Message-ID: https://archive.computerhistory.org/resources/access/text/2018/11/102740473-05-01-acc.pdf ?? On Wed, May 11, 2022 at 3:08 AM ED SHARPE via cctalk wrote: > > Were did you find that reference. Gavin? > > Sent from the all new AOL app for Android > > On Tue, May 10, 2022 at 5:02 PM, Gavin Scott wrote: Perhaps: "Molecular Electronics Branch, Electronic Technology > Division, Air Force Avionics Laboratory, Wright-Patterson Air Force > Base, Ohio." > > On Tue, May 10, 2022 at 5:31 PM ED SHARPE via cctalk > wrote: > > > > Who/what is Molecular Electronics Branch Electronic Technology Division thanks Ed# > > > > Sent from the all new AOL app for Android > -- -Jon +44 7792 149029 From couryhouse at aol.com Thu May 12 06:00:11 2022 From: couryhouse at aol.com (ED SHARPE) Date: Thu, 12 May 2022 11:00:11 +0000 (UTC) Subject: Who/what is Molecular Electronics Branch Electronic Technology Division In-Reply-To: References: <1883523987.1014566.1652221852814.ref@mail.yahoo.com> <1883523987.1014566.1652221852814@mail.yahoo.com> <157668945.1046190.1652234883003@mail.yahoo.com> Message-ID: <1308663720.1361442.1652353211978@mail.yahoo.com> YEP THAT IS? PART OF? TE PICTURE THX? ?ED# In a message dated 5/12/2022 3:22:23 AM US Mountain Standard Time, cctalk at classiccmp.org writes:? https://archive.computerhistory.org/resources/access/text/2018/11/102740473-05-01-acc.pdf ?? On Wed, May 11, 2022 at 3:08 AM ED SHARPE via cctalk wrote: > > Were did you find that reference. Gavin? > > Sent from the all new AOL app for Android > >? On Tue, May 10, 2022 at 5:02 PM, Gavin Scott wrote:? Perhaps: "Molecular Electronics Branch, Electronic Technology > Division, Air Force Avionics Laboratory, Wright-Patterson Air Force > Base, Ohio." > > On Tue, May 10, 2022 at 5:31 PM ED SHARPE via cctalk > wrote: > > > > Who/what is Molecular Electronics Branch Electronic Technology Division thanks Ed# > > > > Sent from the all new AOL app for Android > -- -Jon +44 7792 149029? From cctalk at beyondthepale.ie Thu May 12 06:42:12 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 12:42:12 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <01SD42SCH40C8X0VQA@beyondthepale.ie> Maciej W. Rozycki wrote: > On Thu, 12 May 2022, Peter Coghlan via cctalk wrote: > >> Anyway, the good news is that I think I have found the source of the >> problem. One of the capacitors used to filter the (DC?, pulsed DC?, >> rippled DC?, biased AC?) supply to the 9V regulator is marked 330uF/25V. >> It reads 6uF on the capacitance range on my multimeter. This can't be >> helping the cause. It's not showing any signs of leakage but it's got >> a brown sleeve and the same logo as the nasty, leaky SXF capacitors but >> it is marked KME. (I said there was only one capacitor in the filter >> in a previous posting. Originally I managed to spot a little 10uF/100V >> capacitor but somehow failed to notice the chubbier 330uF/25V capacitor >> completing a PI filter with a small choke...) > > Likely just a general purpose capacitor. I only have 2 330uF/25V 85?C > Nichicon SE parts listed for the H7821 (and I have a note about one PSU of > this kind having a 220uF/35V part in place of one of those too). Also no > 100V parts at all, but 4 10uF/35V 105?C parts, either Teapo SE or Daewoo > RS. Teapo SE and Chemi-con KME series are standard general purpose parts > and given the low temperature rating Nichicon SE are likely such as well. > > I guess especially for standard capacitors factories ordered whatever was > readily available whereas with the high-ripple low-impedance/ESR parts the > choice was much more limited. > Hi Maciej, I replaced the capacitor in question with a blue Nichicon SE of the same value scavanged from another H7821 until I order some spares. I now have 8.7V available on the 9V supply, a little less than I hoped for but it is enough to make the internal thinwire tranceiver happy. Now there is just the seized fan to deal with. Thanks again to you and Tony for leading me in the direction of the likely source of this fault. I would never have thought of looking in the power supply to find it. Regards, Peter. > > Maciej > From cctalk at beyondthepale.ie Thu May 12 09:00:20 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 15:00:20 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <01SD48HC0O4Q8X0VQA@beyondthepale.ie> > > Wayne: AC DC terminology has been well documented since the 1800's. > Don't try to reinvent the terms or no one will know what you are talking about. > I answered a few things below... > They didn't have switch mode power supplies in the 1800s. Terms like AC and DC as understood back then can be used to describe what goes in to and comes out of this power supply but they are not ideal for describing what's going on in the middle of it. It seems like an unusual sort of design to me. I haven't come across the idea of extracting ripple from one output and using it to create another output before. It took me a long time to figure out what was going on. Maybe it is a common thing to do and I haven't seen it because of my lack of experience with this sort of thing? Could anyone who is more familiar with switch mode power supplies comment? Anyway, I was just trying to describe what I've seen. > > Wayne: Alternating Current is a continuously varying sine wave. The polarity > does reverse over time. Perhaps Alternating Current isn't a good term and > should be Alternating voltage instead but AC is the terminology and it > describes the form of the wave. Is basically says that there is a zero to > positive component and a zero to negative component of the voltage as > measured over time in 2 half waves > Ok. I doubt we will find many true sine waves inside this power supply though. > > Wayne: There is no AC component. The output from a rectifier is pulsed DC, > either half wave or full wave. An additional circuit after the rectifier > provides the smoothing to provide nearly pure DC. Nearly pure meaning the > voltage remains constant and does not drop much when measured over time. > The most pure DC source is a battery. Transformers work on AC or Pulsed DC. > It depends on your definition of AC component. How about we say the output of a rectifier consists of a steady component plus a varying component? I guess you could call it pulsed DC if you want. Whatever it is, when you put it through a transformer, what you get out the other side will have a varying component and no steady component. The output of the transformer is probably vaguely sinusoidal because the performance of the core is likely to fall off as frequency rises. It could be described as AC. It could not be described as pulsed DC. > > Wayne: There is no negative component of Pulsed DC so no AC. > As before, how about we call it a steady component plus a varying component? > > Wayne. Lotta good text on this out there. Basically a variable current > induced through a wire generates a magnetic field. Any wire placed next > to it, has that field induced in it as well. The catch is that the field > has to pulse or alternate to keep generating the field and being induced > into the other wire. It's the movement IE the up and down motion of the > voltage that causes the field to be induced in the other wire. > In a transformer, it is the variation of the current in one wire which creates a varying magnetic field which induces a current in the other wire. > > Wayne: I just got an Dec AlphaStation 200. Look like its running NT though. > It's probably ok but check the power supply for leaky capacitors! Have a look around for batteries that might leak while it was/is in storage too! > > > > > ? The ripple on the rectified 5V and 12V supplies gets transformed > > into an isolated AC source for the 9V supply. ? > > Shouldn?t that be ?pulsed DC? instead of ?AC? as rectification > > changes AC to DC ? > No, it shouldn't. What goes into the transformer could be described as pulsed DC. What comes out of the transformer cannot be described as pulsed DC. It has a varying component and no steady component, therefore I described it as AC. Regards, Peter Coghlan. From toby at telegraphics.com.au Thu May 12 10:13:38 2022 From: toby at telegraphics.com.au (Toby Thain) Date: Thu, 12 May 2022 11:13:38 -0400 Subject: DEC H7822 power supply In-Reply-To: <01SD3BDFJWHI8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <29aed0bf-0282-2d15-05ff-5f83889f81f1@telegraphics.com.au> On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: > It's hard to come up with suitable terms for this sort of stuff that > convey the meaning of what is going on. I struggled with it for a while > and that was what I ended up with. > > With the strict meaning of DC and AC being direct current and alternating > current and given that we are often talking about voltages rather than > currents, meanings are already getting stretched. Besides, what's direct > about it? Maybe it would be more accurate to use terms like steady voltage Many textbooks (and wikipedia) define DC as "in one direction", which is accurate. There is no need to refer to voltage; DC is indeed descriptive of the _current_ not voltage. "Constant voltage" is not a synonym for "DC", although it is a subset of DC we frequently encounter. > and alternating voltage? Alternating doesn't seem like that good a term > either. To me it suggests some sort of square wave switching very rapidly > between one extreme and another, not a nice lazy sine wave which is the > normally accepted meaning. Likewise, alternating means "alternating direction". > > Given the normal usage that has evolved for the terms DC and AC rather than > their dictionary definitions, I would suggest that the current that gets > passed by a rectifier has both a DC component and an AC component. When It does not, due to unidirectionality. > this mixture is fed into a transformer primary as in this case, the DC > component does not pass through from the primary to the secondary but the > AC component does. Transformers only work on AC, right? > > Or maybe it could equally be said that a transformer can be used to convert > pulsed DC to AC? > ... > Regards, > Peter Coghlan. > > > Sent from my DEC Alphaserver 800 > > Wayne S wrote: >> >> ? The ripple on the rectified 5V and 12V supplies gets transformed into an >> isolated AC source for the 9V supply. ? >> Shouldn?t that be ?pulsed DC? instead of ?AC? as rectification >> changes AC to DC ? >> >> >> Sent from my iPhone >> >>> On May 11, 2022, at 01:36, Peter Coghlan via cctalk wrote: >>> >>> The ripple on the rectified 5V and 12V supplies gets transformed into an >>> isolated AC source for the 9V supply. >> From toby at telegraphics.com.au Thu May 12 10:14:57 2022 From: toby at telegraphics.com.au (Toby Thain) Date: Thu, 12 May 2022 11:14:57 -0400 Subject: DEC H7822 power supply In-Reply-To: <4e87131-de8-a66-fb7-f138748da036@informatik.uni-stuttgart.de> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <4e87131-de8-a66-fb7-f138748da036@informatik.uni-stuttgart.de> Message-ID: On 2022-05-12 4:40 a.m., Christian Corti via cctalk wrote: > On Thu, 12 May 2022, Peter Coghlan wrote: >> about it?? Maybe it would be more accurate to use terms like steady >> voltage >> and alternating voltage? Alternating doesn't seem like that good a term > > In German it's exactly like you suggest it. We say "Gleichspannung" (= > constant/steady voltage) and "Wechselspannung" (=alternating voltage) > > I also hate the English/American expression "inverter" for voltage > converters, because really nothing is being inverted in any way. > Generating AC from DC _does_ always involve generation of "inverted" voltages relative to the input DC (AC has positive and negative cycles), so the term isn't really strange? > But hey, they still have inches and feet and ounzes (be they fluid or > solid) and gallons, so what can I expect? ;-)))) > > Christian From macro at orcam.me.uk Thu May 12 10:39:27 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Thu, 12 May 2022 16:39:27 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <2828A7E5-5E31-47AA-A67C-D17AF97E1457@comcast.net> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <2828A7E5-5E31-47AA-A67C-D17AF97E1457@comcast.net> Message-ID: On Wed, 11 May 2022, Paul Koning wrote: > > I guess especially for standard capacitors factories ordered whatever was > > readily available whereas with the high-ripple low-impedance/ESR parts the > > choice was much more limited. > > I wonder if nowadays a good replacement for the case where low ESR is > needed would be a big ceramic capacitor. Unlike the old days those now > can be had in many-?F capacitances. Possibly, in the lower capacitance range, if not for the horrendous price, e.g. $50/?40 each for a 470?F/25V part: (at least you get free shipping for just one piece). There's still little choice for the higher range parts found in DEC PSUs, such as 1800?F/25V, 4700?F/10V or 6800?F/20V even. With aluminium organic polymer capacitors rated voltage also quickly drops for higher capacitances, so you won't get any of these as replacements either. I don't know offhand to what extent these limitations come from current technology vs the laws of physics. Maciej From macro at orcam.me.uk Thu May 12 11:12:33 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Thu, 12 May 2022 17:12:33 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SD42SCH40C8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD42SCH40C8X0VQA@beyondthepale.ie> Message-ID: On Thu, 12 May 2022, Peter Coghlan via cctalk wrote: > I replaced the capacitor in question with a blue Nichicon SE of the same > value scavanged from another H7821 until I order some spares. I now have > 8.7V available on the 9V supply, a little less than I hoped for but it is > enough to make the internal thinwire tranceiver happy. Now there is just > the seized fan to deal with. Tolerance is 5% on this line, so you're well within. > Thanks again to you and Tony for leading me in the direction of the likely > source of this fault. I would never have thought of looking in the power > supply to find it. You are welcome! I wish I had the skills to actually diagnose a faulty PSU myself like you do. Experience has taught me to look into the PSU first for all kinds of odd phenomena. For example I had a WiFi+5-port 100BASE-TX Ethernet bridge which stopped talking to one particular device, a 10BASE-T to 10BASE2 media converter/repeater regardless of the port it was wired to; IIRC frame reception worked, but transmission did not make it through. It cost me a lot of hair pulling to sort it, including actually buying a brand new identical media converter, the first suspect, as it was the only device that caused the bridge to exhibit its odd behaviour. Which did not help of course and the new device triggered exactly the same symptoms. Eventually it has turned out to be the bridge's PSU being on its way out. It was one of those nasty plug top PSUs that are not worth even looking inside, and just replacing it with a new one (which of course cost more than the bridge combined with its PSU originally did!) cured the problem. Out of 4 such bridges I bought ~15 years ago 3 are still in service, but all their PSUs had to be replaced. At least they had a standard connector for the power plug (the newer replacement devices don't anymore, sigh). The 4th bridge, the same that caused problems, started having more issues with its wired ports later on if more than 2 devices were plugged IIRC, with no clear reason except for suspision of a power deficit, so I put it aside with a plan to recap it and see whether it helps (this discussion just reminded me about it, so maybe I'll try doing it over the coming weekend as I have since got the parts required). And it was just one of many incidents I had with PSUs playing tricks, so the PSU is now my first and primary suspect if a device misbehaves in a way that cannot be clearly attributed to a software bug (which is by far the most common case nowadays, a clear sign of a generation change to me). Maciej From cctalk at beyondthepale.ie Thu May 12 10:37:01 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 16:37:01 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: <29aed0bf-0282-2d15-05ff-5f83889f81f1@telegraphics.com.au> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> Message-ID: <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> Toby Thain via cctalk wrote: > On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: >> >> Given the normal usage that has evolved for the terms DC and AC rather than >> their dictionary definitions, I would suggest that the current that gets >> passed by a rectifier has both a DC component and an AC component. When >> > > It does not, due to unidirectionality. > Consider the current through the rectifier as the sum of a "DC" current plus an "AC" current. The "DC" current has a steady positive value and the "AC" current varies above and below zero with a magnitude less than or equal to that of the "DC" current. When the two are summed, the result is a varying current which does not go below zero. This is what I mean by it having a DC component and an AC component. This sort of analysis often used in electronic engineering to break down more complex entities into simpler ones which can be analysed separately with greater ease. Didn't somebody have a theorem or an axiom or something that says this is a valid way to do it? I forget who. It was a long time ago. Kirchoff maybe? No, it wasn't him, maybe he was the one that said the sum of currents into and out of nodes is zero and stuff like that... It is a particularly suitable strategy for the case in hand because a transformer will not pass "DC" from primary to secondary so the effect of this component can be ignored (except that it could cause the transformer core to saturate which must be allowed for. This is only relevant to the designer of the power supply but if I don't mention it, someone will surely tell me that I should have.) (I am starting to regret making the effort to accurately describe this unusual and confusing (to me anyway) circuit for the benefit of others who might find themselves struggling with this power supply as I was and might find some hints on how it operates to be helpful.) Regards, Peter Coghlan. From dkelvey at hotmail.com Thu May 12 12:03:00 2022 From: dkelvey at hotmail.com (dwight) Date: Thu, 12 May 2022 17:03:00 +0000 Subject: Recent purchase of NIC-80 computer. Message-ID: Hi All There was a Nicolet computer purchased recently on ebay: https://www.ebay.com/bfl/viewbids/363826255294?item=363826255294&rt=nc&_trksid=p2047675.l2565 Looking at the buyers history, it looks like it was purchased by a collector. Bob Rosenbloom and I are wondering if anyone know who might have purchased it and if they are expecting to restore it to operational status? These are an interesting computer being that it is a 20 bit word. It was also designed specifically to do FFT's with specialized instructions like bit reversing and hardware multiply and divide. It also has an built in A/D that can have different bandwidth, depending on sample size. The original design was for NMR chemical analysis. But was especially useful for acquiring repeating sampled evens that had low signal to noise because of its hardware built in analog acquisition capable of multiple samples to accumulate multiple pass without requiring action by the processor. We were hoping to see if the person that acquired the computer was interested in restoring it to operational status. Bob and I have accumulated a significant amount of both hardware and software for this computer. I am also quite good at trouble shooting this design as I original brought my NIC-80 back to life without schematics (we now have a schematic set, thanks to a fellow in Australia that had a set of manuals ). The person that bought it would have been relatively close in Wisconsin, as it was a pick up local item. Thanks Dwight From paulkoning at comcast.net Thu May 12 12:13:32 2022 From: paulkoning at comcast.net (Paul Koning) Date: Thu, 12 May 2022 13:13:32 -0400 Subject: DEC H7822 power supply In-Reply-To: <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> Message-ID: > On May 12, 2022, at 11:37 AM, Peter Coghlan via cctalk wrote: > > Toby Thain via cctalk wrote: >> On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: >>> Given the normal usage that has evolved for the terms DC and AC rather than >>> their dictionary definitions, I would suggest that the current that gets >>> passed by a rectifier has both a DC component and an AC component. When >>> >> >> It does not, due to unidirectionality. >> > > Consider the current through the rectifier as the sum of a "DC" current plus > an "AC" current. The "DC" current has a steady positive value and the "AC" > current varies above and below zero with a magnitude less than or equal to > that of the "DC" current. > > When the two are summed, the result is a varying current which does not go > below zero. This is what I mean by it having a DC component and an AC > component. Sure, that's the standard way to look at a signal. It becomes very obvious when you do a Fourier transform; you see a term at f=0 (the DC offset) and terms at f equal to multiples of the mains frequency. paul From paulkoning at comcast.net Thu May 12 12:15:28 2022 From: paulkoning at comcast.net (Paul Koning) Date: Thu, 12 May 2022 13:15:28 -0400 Subject: Recent purchase of NIC-80 computer. In-Reply-To: References: Message-ID: <97E2485D-B903-4C06-94F7-81AC9B9F5FA4@comcast.net> > On May 12, 2022, at 1:03 PM, dwight via cctalk wrote: > > Hi All > There was a Nicolet computer purchased recently on ebay: > https://www.ebay.com/bfl/viewbids/363826255294?item=363826255294&rt=nc&_trksid=p2047675.l2565 > Looking at the buyers history, it looks like it was purchased by a collector. > Bob Rosenbloom and I are wondering if anyone know who might have purchased it and if they are expecting to restore it to operational status? > These are an interesting computer being that it is a 20 bit word. It was also designed specifically to do FFT's with specialized instructions like bit reversing and hardware multiply and divide. That may simply be a quite ordinary DSP processor. Hardware multiply and in particular single cycle mul + add are typical DSP operations because you need them for FIR filters, one of the most common applications of a DSP. And of course bit reverse for FFT, which has the nice property of being very easy in hardware. paul From toby at telegraphics.com.au Thu May 12 12:40:47 2022 From: toby at telegraphics.com.au (Toby Thain) Date: Thu, 12 May 2022 13:40:47 -0400 Subject: DEC H7822 power supply In-Reply-To: <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> Message-ID: <43d81ff9-d0a3-0be1-0939-0546352df69c@telegraphics.com.au> On 2022-05-12 11:37 a.m., Peter Coghlan via cctalk wrote: > Toby Thain via cctalk wrote: >> On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: >>> >>> Given the normal usage that has evolved for the terms DC and AC >>> rather than >>> their dictionary definitions, I would suggest that the current that gets >>> passed by a rectifier has both a DC component and an AC component.? When >>> >> >> It does not, due to unidirectionality. >> > > Consider the current through the rectifier as the sum of a "DC" current > plus > an "AC" current.? The "DC" current has a steady positive value and the "AC" > current varies above and below zero with a magnitude less than or equal to > that of the "DC" current. > > When the two are summed, the result is a varying current which does not go > below zero.? This is what I mean by it having a DC component and an AC > component. Sure, if you change the reference point, a DC signal under one reference ("zero") potential becomes AC under a different potential. The definitions are relative to a reference, in order to define the current direction. > > This sort of analysis often used in electronic engineering to break down > more complex entities into simpler ones which can be analysed separately > with greater ease.? Didn't somebody have a theorem or an axiom or something > that says this is a valid way to do it? I forget who.? It was a long time > ago.? Kirchoff maybe? No, it wasn't him, maybe he was the one that said > the sum of currents into and out of nodes is zero and stuff like that... > It is a particularly suitable strategy for the case in hand because a > transformer will not pass "DC" from primary to secondary so the effect of > this component can be ignored (except that it could cause the transformer > core to saturate which must be allowed for.? This is only relevant to the > designer of the power supply but if I don't mention it, someone will > surely tell me that I should have.) > > (I am starting to regret making the effort to accurately describe this > unusual and confusing (to me anyway) circuit for the benefit of others who > might find themselves struggling with this power supply as I was and might > find some hints on how it operates to be helpful.) > > Regards, > Peter Coghlan. From wh.sudbrink at verizon.net Thu May 12 13:01:50 2022 From: wh.sudbrink at verizon.net (William Sudbrink) Date: Thu, 12 May 2022 14:01:50 -0400 Subject: HP 54200D oscope practically worthless? References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> Message-ID: <106801d8662a$5bdb54f0$1391fed0$@verizon.net> I picked up one of these in a batch of electronics. Is it worth repairing/investigating? I don't see much on the web and they seem to go for practically nothing on epay. Is there something inherently wrong with them? Thanks, Bill S. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From romietoo9ibi at xx.vu Thu May 12 13:25:05 2022 From: romietoo9ibi at xx.vu (Alexander Huemer) Date: Thu, 12 May 2022 18:25:05 +0000 Subject: HP 54200D oscope practically worthless? In-Reply-To: <106801d8662a$5bdb54f0$1391fed0$@verizon.net> References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> Message-ID: <20220512182505.huotkiabeiyburj5@ghost.xx.vu> On Thu, May 12, 2022 at 02:01:50PM -0400, William Sudbrink via cctalk wrote: > I picked up one of these in a batch of electronics. Is it worth > repairing/investigating? > I don't see much on the web and they seem to go for practically nothing on > epay. > Is there something inherently wrong with them? The scope does what it is supposed to, you get a time-domain visualization of voltage. Though, they are awkward to use due to the lack of rotary encoders. Scaling horizontally or vertically requires you to go into a menu, navigate to the right option, do the actual scaling and go back. It's better than no scope at all, but not exactly the model you'd hunt. -Alex From drb at msu.edu Thu May 12 13:31:14 2022 From: drb at msu.edu (Dennis Boone) Date: Thu, 12 May 2022 14:31:14 -0400 Subject: HP 54200D oscope practically worthless? In-Reply-To: (Your message of Thu, 12 May 2022 18:25:05 -0000.) <20220512182505.huotkiabeiyburj5@ghost.xx.vu> References: <20220512182505.huotkiabeiyburj5@ghost.xx.vu> <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> Message-ID: <20220512183114.2AD3C403DE9@yagi.h-net.msu.edu> > The scope does what it is supposed to, you get a time-domain > visualization of voltage. Though, they are awkward to use due to the > lack of rotary encoders. Scaling horizontally or vertically requires > you to go into a menu, navigate to the right option, do the actual > scaling and go back. It's better than no scope at all, but not > exactly the model you'd hunt. It has HP-IB, and the manuals mention the HP desktop computers of that era, so you could probably build a more facile interface on a modern machine. De From wh.sudbrink at verizon.net Thu May 12 13:57:52 2022 From: wh.sudbrink at verizon.net (William Sudbrink) Date: Thu, 12 May 2022 14:57:52 -0400 Subject: HP 54200D oscope practically worthless? In-Reply-To: <20220512182505.huotkiabeiyburj5@ghost.xx.vu> References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> <20220512182505.huotkiabeiyburj5@ghost.xx.vu> Message-ID: <106d01d86632$2f2bb0a0$8d8311e0$@verizon.net> Alexander Huemer wrote: > The scope does what it is supposed to, you get a > time-domain visualization of voltage. Though, they > are awkward to use due to the lack of rotary encoders. > Scaling horizontally or vertically requires you to go into > a menu, navigate to the right option, do the actual > scaling and go back. > It's better than no scope at all Yea, I have several other scopes, so I guess I won't spend any time on it... > but not exactly the model you'd hunt. Anybody in the Washington, DC area want to pick it up for a beer? -Alex -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus From stueberahoo at yahoo.de Thu May 12 14:37:02 2022 From: stueberahoo at yahoo.de (Anke =?utf-8?Q?St=C3=BCber?=) Date: Thu, 12 May 2022 21:37:02 +0200 Subject: Lecture: The Danish Data History Association is on the move, 2022-05-14, 19:00 References: <20220512193701.GB6607.ref@cortexcerebri.geruempel.org> Message-ID: <20220512193701.GB6607@cortexcerebri.geruempel.org> Hi all, you're invited to the Update computer club[0] public lecture series "Updateringar"[1]! When: 2022-05-14, 19:00 CEST Where: https://bbb.cryptoparty.se/b/upd-0mo-m2u-aq8 The Danish Data History Association is on the move ? We, the Danish Data History Association (Dansk Datahistorisk Forening), were founded more than 20 years ago and have primarily lived (quietly) underground in a cellar in the outskirts of Copenhagen. In 2020 the municipality of Ballerup, who were our hosts, decided to use the approx. 1000 m? for other purposes than us. Two years later ? in February 2022 ? we had a "grand" opening of our new experimental data museum with a 600 m? exhibition. What happened? And what's the plan moving forward? Michael ?rn? (DDHF) The lecture is free and open to everyone. Don't want to miss upcoming events? Subscribe to our low-traffic announcement list here[2]! Hope to see you there, Anke [0] https://www.dfupdate.se/en/ [1] https://wiki.dfupdate.se/projekt:updateringar [2] https://lists.dfupdate.se/postorius/lists/announce.lists.dfupdate.se From elson at pico-systems.com Thu May 12 15:36:22 2022 From: elson at pico-systems.com (Jon Elson) Date: Thu, 12 May 2022 15:36:22 -0500 Subject: HP 54200D oscope practically worthless? In-Reply-To: <106801d8662a$5bdb54f0$1391fed0$@verizon.net> References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> Message-ID: <2dd77f9d-f4f0-d5da-7d63-27fd87ad4791@pico-systems.com> On 5/12/22 13:01, William Sudbrink via cctalk wrote: > I picked up one of these in a batch of electronics. Is it worth > repairing/investigating? > I don't see much on the web and they seem to go for practically nothing on > epay. > Is there something inherently wrong with them? I have a 54200A that I got out of a dumpster.? The user interface is QUITE awful compared to modern digital scopes.? Setting the trigger level requires going through several menus, for instance. But, it is a decent scope except for the human-machine interface. Jon From dancohoe at oxford.net Thu May 12 15:45:18 2022 From: dancohoe at oxford.net (dancohoe at oxford.net) Date: Thu, 12 May 2022 16:45:18 -0400 Subject: Nicolet Computer interest Message-ID: Hi Dwight, In 2010 I purchased a Nicolet LAS 12/70 Data and Signal Processor System box on ebay. I hoped it was a Nicolet computer but then could find nothing online about it. It's on the shelf here and I've never looked inside to see what's there. It's ridiculously heavy. I don't know if there's anything useful from it for you guys, but I can take a look at what is on the inside and report back. Regards, Dan From cctalk at beyondthepale.ie Thu May 12 14:14:13 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 20:14:13 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> Message-ID: <01SD4KYJFUNE8X0VQA@beyondthepale.ie> Wayne S wrote: >> On May 12, 2022, at 09:56, Peter Coghlan via cctalk wrote: >> >> ?Toby Thain via cctalk wrote: >>>> On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: >>>> Given the normal usage that has evolved for the terms DC and AC rather than >>>> their dictionary definitions, I would suggest that the current that gets >>>> passed by a rectifier has both a DC component and an AC component. When >>>> >>> >>> It does not, due to unidirectionality. >>> >> >> Consider the current through the rectifier as the sum of a "DC" current plus >> an "AC" current. The "DC" current has a steady positive value and the "AC" >> current varies above and below zero with a magnitude less than or equal to >> that of the "DC" current. > > I?m really trying to understand what you?re getting at here. > In practical terms, The assumption that there is a sum of a DC and AC > component is incorrect. Why? What evidence do you have that the assumption is incorrect? If I am trying to calculate the height a sea harbour wall needs to be, can I not consider the height of the tide and the height of the waves separately and add them together, just to make it easier to work it out even though I know that it would be physically impossible to distinguish the water that makes up the tide from the water that makes up the waves? (It's not even that bad in the case of electric current because instruments exist which can measure the DC component of a current and the AC component of a current separately or together.) > > There is no DC component in an AC wave. A wave is either AC meaning > reversing polarity or it is DC meaning there is no reversal of polarity. > Can we agree that there is such a thing as an "AC current" and there is such a thing as a "DC current" and the two of them can be added together? How about we take a 3V doorbell transformer and make a circuit consisting of the secondary of the transformer, a 6V battery and a 9V light bulb all connected in series? How would the current in this circuit be described? A varying current? An AC current? A DC current? How about we use a 6V doorbell transformer and a 3V battery instead? Would that change how the current is described? I would say that in both cases, the current flowing has an AC component and it also has a DC component. > > And a rectifier does not sum anything. > I'm not saying the rectifier sums anything. What I am saying is that the current that goes through the rectifier can be considered as the sum of two component currents. It's just a way of looking at it, like considering the tide and the waves separately in the harbour wall calculation. > > Are you maybe using ?Rectifier? as the whole circuit? A Rectifier > can be a single component, like a diode used to pass one half of an > alternating current or it can be a few components like 4 diodes connected > as a bridge to pass both halfs. > Strictly speaking, a circuit involves a closed path for a current to flow in. However, "circuit" also gets used to describe a substantial group of components that needs to be connected to something else to form a fully closed path. I don't think a rectifier would be enough to be considered a whole circuit. > > This may help to visualize. > Do an experiment. If you have an Oscope take a small battery maybe 9 volt and > wire the negative lead to the neg scope input. Touch the positive lead to the > scope positive and watch the deflection. You should see a quick trace rise > and the trace should remain above the zero point. > That is what pure DC looks like. No ripple at all. Power Supplies try to make > that from your wall power input. > Next, untouch the positive and watch the trace fall. At no point does it fall > below the zero line. > NoW touch and untouch the positive as fast as you can and watch the trace. > That is pulsating DC although with irregular frequency. That would be the > output from the rectifier component. > Reverse the leads and do it again. > This will show the equivalent of a negative polarity. > > If you have a variac, set it to 9 volts or so, plug in a light or something to > provide a load and using your oscilloscope probes touch across the light and > you should see a sine wave with regular frequency. Notice the negative going > half. That is AC. > > > It?s important to use a variac for safety ( or an isolation transformer very > carefully) as wall voltages can hurt you. > A variac does not provide isolation. If it is not wired correctly, it is possible to end up scooping 9V from the live end of the mains supply instead of from the neutral end. If there is a bad connection or a break in the winding near or at the neutral end, it is possible to end up with the whole mains supply at the output. I don't want to connect the earth lead of my scope probe to the neutral output of a variac either. If I were doing this, I would prefer to use a transformer designed to provide an isolated fixed low voltage output. > > This is a very good way to visually explain AC and DC. > It can be used to visualise AC and DC voltages but it is not quite as good for currents. How do I get myself into these quagmires? I just wanted to describe the obscure (to me) circuit I found in a DEC H7821 power supply in case anyone else needs to know how it seems to work. I would be delighted if someone else who is familiar with this power supply or power supplies like it could take a look at my findings and say whether I figured it out correctly or not. If anybody else is working on a fault in this power supply or a similar power supply, I would be happy to answer any questions they have about how I think it works or how to disassemble it or what failed in mine or anything else about it that I figured out along the way. Other than that, I suspect many of the other mailing list members are starting to find the going a bit heavy by now. Regards, Peter Coghlan. > >> When the two are summed, the result is a varying current which does not go >> below zero. This is what I mean by it having a DC component and an AC >> component. >> >> This sort of analysis often used in electronic engineering to break down >> more complex entities into simpler ones which can be analysed separately >> with greater ease. Didn't somebody have a theorem or an axiom or something >> that says this is a valid way to do it? I forget who. It was a long time >> ago. Kirchoff maybe? No, it wasn't him, maybe he was the one that said >> the sum of currents into and out of nodes is zero and stuff like that... >> It is a particularly suitable strategy for the case in hand because a >> transformer will not pass "DC" from primary to secondary so the effect of >> this component can be ignored (except that it could cause the transformer >> core to saturate which must be allowed for. This is only relevant to the >> designer of the power supply but if I don't mention it, someone will >> surely tell me that I should have.) >> >> (I am starting to regret making the effort to accurately describe this >> unusual and confusing (to me anyway) circuit for the benefit of others who >> might find themselves struggling with this power supply as I was and might >> find some hints on how it operates to be helpful.) >> >> Regards, >> Peter Coghlan. From wrcooke at wrcooke.net Thu May 12 16:24:03 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Thu, 12 May 2022 16:24:03 -0500 (CDT) Subject: DEC H7822 power supply In-Reply-To: <01SD4KYJFUNE8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> <01SD4KYJFUNE8X0VQA@beyondthepale.ie> Message-ID: <544988424.4917460.1652390643067@email.ionos.com> > On 05/12/2022 2:14 PM Peter Coghlan via cctalk wrote: > > > Wayne S wrote: > >> On May 12, 2022, at 09:56, Peter Coghlan via cctalk wrote: > >> > >> Toby Thain via cctalk wrote: > >>>> On 2022-05-11 7:02 p.m., Peter Coghlan via cctalk wrote: > >>>> Given the normal usage that has evolved for the terms DC and AC rather than > >>>> their dictionary definitions, I would suggest that the current that gets > >>>> passed by a rectifier has both a DC component and an AC component. When > >>>> > >>> > >>> It does not, due to unidirectionality. > >>> > >> > >> Consider the current through the rectifier as the sum of a "DC" current plus > >> an "AC" current. The "DC" current has a steady positive value and the "AC" > >> current varies above and below zero with a magnitude less than or equal to > >> that of the "DC" current. > > > > I?m really trying to understand what you?re getting at here. > > In practical terms, The assumption that there is a sum of a DC and AC > > component is incorrect. > Why? What evidence do you have that the assumption is incorrect? > > If I am trying to calculate the height a sea harbour wall needs to be, can I > not consider the height of the tide and the height of the waves separately > and add them together, just to make it easier to work it out even though I > know that it would be physically impossible to distinguish the water that > makes up the tide from the water that makes up the waves? > > (It's not even that bad in the case of electric current because instruments > exist which can measure the DC component of a current and the AC component > of a current separately or together.) > > Peter, You are quite correct. It is called superposition. https://en.wikipedia.org/wiki/Superposition_principle It applies to all linear systems and is one of the principles that make many difficult problems practicable. My background is primarily physics. Superposition is extremely important there in many realms, including signal processing, electric circuits, and differential equations, among many others. I'll say no more. I didn't want to get into this quagmire, either. Will From dkelvey at hotmail.com Thu May 12 16:25:05 2022 From: dkelvey at hotmail.com (dwight) Date: Thu, 12 May 2022 21:25:05 +0000 Subject: Recent purchase of NIC-80 computer. In-Reply-To: <97E2485D-B903-4C06-94F7-81AC9B9F5FA4@comcast.net> References: <97E2485D-B903-4C06-94F7-81AC9B9F5FA4@comcast.net> Message-ID: Hi Paul It may be a little slow for DSP. Its main thing was that the acquisition didn't require and processor time. It was designed before uPs. ( not counting what was used in the F16's ). It is fun because it has a full front panel to toggle in a bootstrap. Then one can load with the serial. Mine also has a floppy drive ( something is broken right now ). I also have a Diablo 30 for it but haven't had time to play with it. The floppy was working at one time. I had to rewrite the low level code for the floppy from code I had for the diablo. Bob has no mass storage yet. It is on his list of projects. Dwight ________________________________ From: Paul Koning Sent: Thursday, May 12, 2022 10:15 AM To: dwight ; cctalk at classiccmp.org Subject: Re: Recent purchase of NIC-80 computer. > On May 12, 2022, at 1:03 PM, dwight via cctalk wrote: > > Hi All > There was a Nicolet computer purchased recently on ebay: > https://www.ebay.com/bfl/viewbids/363826255294?item=363826255294&rt=nc&_trksid=p2047675.l2565 > Looking at the buyers history, it looks like it was purchased by a collector. > Bob Rosenbloom and I are wondering if anyone know who might have purchased it and if they are expecting to restore it to operational status? > These are an interesting computer being that it is a 20 bit word. It was also designed specifically to do FFT's with specialized instructions like bit reversing and hardware multiply and divide. That may simply be a quite ordinary DSP processor. Hardware multiply and in particular single cycle mul + add are typical DSP operations because you need them for FIR filters, one of the most common applications of a DSP. And of course bit reverse for FFT, which has the nice property of being very easy in hardware. paul From dkelvey at hotmail.com Thu May 12 16:27:19 2022 From: dkelvey at hotmail.com (dwight) Date: Thu, 12 May 2022 21:27:19 +0000 Subject: Nicolet Computer interest In-Reply-To: References: Message-ID: It may have a processor inside. if it is the one I think it is, it uses 2900 ALUs. If you can send a picture I may be able to tell. Dwight ________________________________ From: cctalk on behalf of dancohoe--- via cctalk Sent: Thursday, May 12, 2022 1:45 PM To: 'dwight via cctalk' Subject: Nicolet Computer interest Hi Dwight, In 2010 I purchased a Nicolet LAS 12/70 Data and Signal Processor System box on ebay. I hoped it was a Nicolet computer but then could find nothing online about it. It's on the shelf here and I've never looked inside to see what's there. It's ridiculously heavy. I don't know if there's anything useful from it for you guys, but I can take a look at what is on the inside and report back. Regards, Dan From cctalk at beyondthepale.ie Thu May 12 17:32:39 2022 From: cctalk at beyondthepale.ie (Peter Coghlan) Date: Thu, 12 May 2022 23:32:39 +0100 (WET-DST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> <01SD4KYJFUNE8X0VQA@beyondthepale.ie> Message-ID: <01SD4QZJ70IY8X0VQA@beyondthepale.ie> >> >> If I am trying to calculate the height a sea harbour wall needs to be, can I >> not consider the height of the tide and the height of the waves separately >> and add them together, just to make it easier to work it out even though I >> know that it would be physically impossible to distinguish the water that >> makes up the tide from the water that makes up the waves? >> > Using this analogy if you measured 10 waves at 10 feet high you would need > a wall 100 feet high, correct? Or 20 waves at 7 feet it would need to be > 140 feet. > Not valid at all. > The idea is to measure the maximum height of the waves on a windy day by examining how far up they make splash marks on a vertical pole stuck in the seabed for the purpose. Then consult a tide table to see how high the tide was at the time the wave measurement was made. Subtracting the latter figure from the former figure gives the height of the waves above the tide. (This is the AC component. The tide is the DC component.) Adding the height of the highest expected tide to the figure calculated for the maximum height of the waves would give a figure for the minimum height needed for the harbour wall. > >> (It's not even that bad in the case of electric current because instruments >> exist which can measure the DC component of a current and the AC component >> of a current separately or together.) > I have no idea what you are talking about. What instruments are you referring > to? I?d like to read about them. > A suitable moving coil ammeter will register the average value of a current flowing through it and will indicate which direction it is flowing in. This is the DC component of the current. A suitable moving iron ammeter will (crudely) register the RMS value of the AC current flowing through it. I'm not certain but as far as I recall, it will also register the actual value of DC current. There are probably lots of fancy computerised oscilloscope like instruments that can be used to measure all sorts of oddball current waveforms given suitable current probes. >> >> How about we take a 3V doorbell transformer and make a circuit consisting >> of the secondary of the transformer, a 6V battery and a 9V light bulb all >> connected in series? How would the current in this circuit be described? >> A varying current? An AC current? A DC current? >> > > The current would be described by ohm?s law. Incidentally, if the primary > of a xformer was actually connected it would probably blow up the battery. > Maybe I should have stated that I was assuming that power is applied to the primary for the test? Perhaps I should have also stated that I am assuming that the light bulb is selected such that the current it draws at it's rated voltage will not exceed the capability of either the transformer or the battery? I don't expect anything to blow up assuming we are understanding each other correctly which may not be a valid assumption. > > You would describe it as Open. If not, its just a 6 volt DC circuit. > I don't understand. > >> How about we use a 6V doorbell transformer and a 3V battery instead? Would >> that change how the current is described? > No it wouldn?t. > >> I would say that in both cases, the current flowing has an AC component and >> it also has a DC component. > As stated and not rectified it?s not a valid circuit. > In ps circuits there is a fuse on the secondary side of the circuit usually > after the rectifier-filter circuit to prevent any rectifier shorts from > damaging other components. The transformer secondary, battery and light bulb are all connected in series ie in a circle, end to end. The battery is not going to be bothered by the AC current flowing through it and the presence of the light bulb will limit the current to a safe value. If the battery and the transformer secondary and the light bulb were connected in parallel ie the two terminals of the battery were connected directly to the two terminals of the transformer secondary and the two terminals of the light bulb, that would be a different matter. Either the transformer or the battery or both could be damaged in this case. This is not what I was suggesting. > > Well, the previous example seemed to imply that the output from a rectifier > was pure dc. > Pretty much everything I have said is to try to illustrate that what flows through the rectifier has a DC component and an AC component. > > Its not, it?s pulsed DC > Pulsed DC sounds like something that has a DC component and an AC component. > > so i thought you might be referring > to the rectifier and associated filter and possibly regulator components as > the whole rectifier? > Sometimes in talking about electronics the specific function of a portion > of connected components is cited. IE filter circuit, Detector circuit, > rectifier circuit. It?s just shorthand speak. > Sorry, I didn't follow. I'm going to bow out at this point because I don't there is anything further I can add to this and I am clearly failing to make myself understood. Regards, Peter Coghlan. From spacewar at gmail.com Thu May 12 19:55:12 2022 From: spacewar at gmail.com (Eric Smith) Date: Thu, 12 May 2022 18:55:12 -0600 Subject: HP 54200D oscope practically worthless? In-Reply-To: <20220512182505.huotkiabeiyburj5@ghost.xx.vu> References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> <20220512182505.huotkiabeiyburj5@ghost.xx.vu> Message-ID: On Thu, May 12, 2022 at 12:25 PM Alexander Huemer via cctalk < cctalk at classiccmp.org> wrote: > On Thu, May 12, 2022 at 02:01:50PM -0400, William Sudbrink via cctalk > wrote: > > I picked up one of these in a batch of electronics. Is it worth > > repairing/investigating? > > The scope does what it is supposed to, you get a time-domain > visualization of voltage. > Though, they are awkward to use due to the lack of rotary encoders. > Scaling horizontally or vertically requires you to go into a menu, > navigate to the right option, do the actual scaling and go back. > It's better than no scope at all, but not exactly the model you'd hunt. > These appear to be derived from the 1630/1631 logic analyzers, some models of which have 'scope capability, which works as you've described. They must have decided to offer models with only the scope and without the logic analzyer (except for a digital triggering option), which seems like a bad idea. Probably why I'd never heard of these before. At the time they were current (early 1980s), the 1630/1631 family were fairly reasonable logic analyzers, but the 1650/16500, 1660, 1670/16700, etc. are far better. I wouldn't recommend that anyone _buy_ a 1630/1631 family logic analyzer at this late date, but if someone is giving one away... From glen.slick at gmail.com Thu May 12 20:42:52 2022 From: glen.slick at gmail.com (Glen Slick) Date: Thu, 12 May 2022 18:42:52 -0700 Subject: HP 54200D oscope practically worthless? In-Reply-To: References: <106801d8662a$5bdb54f0$1391fed0$.ref@verizon.net> <106801d8662a$5bdb54f0$1391fed0$@verizon.net> <20220512182505.huotkiabeiyburj5@ghost.xx.vu> Message-ID: On Thu, May 12, 2022 at 5:55 PM Eric Smith via cctalk wrote: > > These appear to be derived from the 1630/1631 logic analyzers, some models > of which have 'scope capability, which works as you've described. They must > have decided to offer models with only the scope and without the logic > analzyer (except for a digital triggering option), which seems like a bad > idea. Probably why I'd never heard of these before. > Without taking a close look at the specifications for any differences, the scope capability of the 54200 might be basically the same as the 1631. The 54201 scope adds a repetitive sampling capability that doesn't appear to be present on the 54200 and 1631, which increases the bandwidth up to 300MHz instead of 50MHz in the real-time sampling mode. From glen.slick at gmail.com Thu May 12 21:03:44 2022 From: glen.slick at gmail.com (Glen Slick) Date: Thu, 12 May 2022 19:03:44 -0700 Subject: Dumping an Intel P8742AH Message-ID: Anyone here have experience dumping the contents of an Intel P8742AH OTP EPROM device? I have one that I haven't been able to dump with either a BP Microsystems BP-1610, or a Data-I/O UniSite device programmer. Both have device entries for that specific device. Both report device connection errors when attempting to read the device. The device pins all look clean. I tried putting a machine pin socket between the device and the programmer ZIF socket in case there was a flakey connection, but that didn't make any difference. I was told the device was working properly in the target system before it was removed to dump its contents. Looking at the UPI-41AH/42AH datasheet 210393-007 the P8742AH does have a security bit which can be programmed. As far as I can tell though, if the security bit is set the device should still respond to the standard device verification algorithm, but just return the wrong data, and the device manufacturer signature should still be able to be read. Or does an Intel P8742AH not respond at all to the standard device verification algorithm if the security bit is set? I don't have the target system myself to reinstall the device and verify that it actually works. From cc at informatik.uni-stuttgart.de Fri May 13 02:20:18 2022 From: cc at informatik.uni-stuttgart.de (Christian Corti) Date: Fri, 13 May 2022 09:20:18 +0200 (CEST) Subject: DEC H7822 power supply In-Reply-To: References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <4e87131-de8-a66-fb7-f138748da036@informatik.uni-stuttgart.de> Message-ID: On Thu, 12 May 2022, Toby Thain wrote: >> I also hate the English/American expression "inverter" for voltage >> converters, because really nothing is being inverted in any way. > Generating AC from DC _does_ always involve generation of "inverted" voltages > relative to the input DC (AC has positive and negative cycles), so the term > isn't really strange? It is very strange and wrong, because alternating != inverting. Making -9V out of +9V would be inverting, making "AC" from "DC" is chopping (along with the chopper circuit, chopper transformer...). Inverting is making something, well, inside out, upside down and the like. That's not appropriate for AC to DC. But this is a cultural thing. Like other terms, e.g. "shipping" although most of the time there is no ship involved. Christian From cc at informatik.uni-stuttgart.de Fri May 13 02:25:43 2022 From: cc at informatik.uni-stuttgart.de (Christian Corti) Date: Fri, 13 May 2022 09:25:43 +0200 (CEST) Subject: DEC H7822 power supply In-Reply-To: <29aed0bf-0282-2d15-05ff-5f83889f81f1@telegraphics.com.au> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <29aed0bf-0282-2d15-05ff-5f83889f81f1@telegraphics.com.au> Message-ID: <77cc1acd-3636-98ed-39a-7273d4c3992f@informatik.uni-stuttgart.de> On Thu, 12 May 2022, Toby Thain wrote: > It does not, due to unidirectionality. But in general, diodes can be (and are) used as controlled AC switches. One good example are the head select diodes in disk drives. You apply a direct voltage and thus "open" the diode. You then have a overlayed alternating voltage coming from the head coils passing through the diodes. This is then AC coupled to the preamplifier. Christian From cc at informatik.uni-stuttgart.de Fri May 13 02:36:08 2022 From: cc at informatik.uni-stuttgart.de (Christian Corti) Date: Fri, 13 May 2022 09:36:08 +0200 (CEST) Subject: DEC H7822 power supply In-Reply-To: <01SD4KYJFUNE8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> <01SD4KYJFUNE8X0VQA@beyondthepale.ie> Message-ID: <7cefebb2-87d9-b521-4b28-f6ec1254bc8@informatik.uni-stuttgart.de> On Thu, 12 May 2022, Peter Coghlan wrote: > Can we agree that there is such a thing as an "AC current" and there > is such a thing as a "DC current" and the two of them can be added > together? Ouch... an alternating current current and direct current current ;-) And you usually add the voltages, not the currents. > A variac does not provide isolation. If it is not wired correctly, it is Good "variacs" provide galvanic isolation from the mains, i.e. they are not autotransformers. > I just wanted to describe the obscure (to me) circuit I found in a DEC H7821 > power supply in case anyone else needs to know how it seems to work. That indeed is really interesting. The only reason that I can imagine why they used the ripple voltage to generate the transceiver voltage is that they "forgot" to implement an extra secondary winding on the transformer (or they reused the transformer from another design). Christian From paulkoning at comcast.net Fri May 13 09:04:37 2022 From: paulkoning at comcast.net (Paul Koning) Date: Fri, 13 May 2022 10:04:37 -0400 Subject: DEC H7822 power supply In-Reply-To: <7cefebb2-87d9-b521-4b28-f6ec1254bc8@informatik.uni-stuttgart.de> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD4BGA7PNQ8X0VQA@beyondthepale.ie> <01SD4KYJFUNE8X0VQA@beyondthepale.ie> <7cefebb2-87d9-b521-4b28-f6ec1254bc8@informatik.uni-stuttgart.de> Message-ID: <83BC2ECD-54AE-4F10-99C0-4D59A9627B40@comcast.net> > On May 13, 2022, at 3:36 AM, Christian Corti via cctalk wrote: > > On Thu, 12 May 2022, Peter Coghlan wrote: > ... >> A variac does not provide isolation. If it is not wired correctly, it is > > Good "variacs" provide galvanic isolation from the mains, i.e. they are not autotransformers. There may be variable transformers that aren't autotransformers, but I've never seen one. The commonly seen Variac devices (either that brand, or analogous devices from other makers) are autotransformers. It should be obvious by inspection which kind you have, and take precautions as needed. paul From macro at orcam.me.uk Sat May 14 08:19:13 2022 From: macro at orcam.me.uk (Maciej W. Rozycki) Date: Sat, 14 May 2022 14:19:13 +0100 (BST) Subject: DEC H7822 power supply In-Reply-To: <01SD48HC0O4Q8X0VQA@beyondthepale.ie> References: <01RGTSDYQHTW8X6K5E@beyondthepale.ie> <01S8BJOYKEQ48WW0VA@beyondthepale.ie> <01SCICHQ3UWC8WYB2W@beyondthepale.ie> <01SCQATK0O3S8X0JVG@beyondthepale.ie> <01SCROBHOYWW8X0JVG@beyondthepale.ie> <01SCS086KXDA8X0JVG@beyondthepale.ie> <01SCV00Y19UI8X0JVG@beyondthepale.ie> <01SD1OILO3OK8X0VQA@beyondthepale.ie> <01SD2GFSEVP28X0VQA@beyondthepale.ie> <01SD3BDFJWHI8X0VQA@beyondthepale.ie> <01SD48HC0O4Q8X0VQA@beyondthepale.ie> Message-ID: On Thu, 12 May 2022, Peter Coghlan via cctalk wrote: > > Wayne: I just got an Dec AlphaStation 200. Look like its running NT though. > > > > It's probably ok but check the power supply for leaky capacitors! Definitely, watch out for possible damage! Prompted I had a peek in mine (an Astec SA180-3505) and it does have lots of the dangerous Chemi-con LXF parts! While mine looks clean and tidy yet (LXF series seem sturdier than older SXF ones), I need to get this sorted sooner rather than later. Thankfully last time I booted it a couple weeks ago it worked just fine. (Strictly speaking I have either an AlphaServer 300 or an AlphaStation 250 system, which are hard to tell apart and the only difference mentioned in DEC documentation between the two mainboards is the maximum amount of DRAM supported, 512MiB vs 256MiB. However both are essentially the same, up to the dedicated sound connector (unused with the AlphaServer), so it's not clear to me if it was a manufacturing option such as a wire bridge put somewhere into the PCB or just a matter of software support. Both kinds of systems use the same firmware, which does not report the system model! And in any case my mainboard has a 54-23787-01 designation, which I'm told is an AlphaStation 250 (an AlphaServer 300 would be 54-23787-02), and also an early version, dated week 51 of 1994, S/N 60, and with lots of hardware patching present, however without the sound option and with an AlphaServer 300 badge and a 1997 date code on the case. Which in any case is exactly the same as with the AlphaStation 200, so the PSU is likely the same as well, so again, do check yours!) > Have a look around for batteries that might leak while it was/is in > storage too! There's a 2032 Lithium coin cell in these systems only, so while it might have been depleted it won't do any harm. Maciej From robert.jarratt at ntlworld.com Sat May 14 12:11:32 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Sat, 14 May 2022 18:11:32 +0100 Subject: Replacement for a DEC 7474 Chip Message-ID: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> Hello, I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a 7474 D flip flop. The problem is I don't know which modern series would be the best one to replace it with. I am sure I have seen a list somewhere of modern equivalents for some DEC chip numbers, but I can't remember where. If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the schematic (p157 of the PDF). Picture of the failed chip here: https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg Can anyone tell me what the best modern equivalent is likely to be? Thanks Rob From jrr at flippers.com Sat May 14 12:41:34 2022 From: jrr at flippers.com (John Robertson) Date: Sat, 14 May 2022 10:41:34 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> Message-ID: On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: > Hello, > > I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a > 7474 D flip flop. The problem is I don't know which modern series > would be the best one to replace it with. I am sure I have seen a list > somewhere of modern equivalents for some DEC chip numbers, but I can't > remember where. > > If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the > schematic (p157 of the PDF). > > Picture of the failed chip here: > https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg > > Can anyone tell me what the best modern equivalent is likely to be? > > Thanks > > Rob > You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. You can use 74S74 or 74F74 as they have the same output current, the "S" is Schottky, and the other is "F"aster. I find that https:///unicornelectronics.com is a reliable source of TTL. John :-#)# -- John's Jukes Ltd. 7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games) flippers.com "Old pinballers never die, they just flip out" From paulkoning at comcast.net Sat May 14 12:48:21 2022 From: paulkoning at comcast.net (Paul Koning) Date: Sat, 14 May 2022 13:48:21 -0400 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> Message-ID: <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> > On May 14, 2022, at 1:41 PM, John Robertson via cctalk wrote: > > On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: >> Hello, >> >> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a >> 7474 D flip flop. The problem is I don't know which modern series >> would be the best one to replace it with. I am sure I have seen a list >> somewhere of modern equivalents for some DEC chip numbers, but I can't >> remember where. >> >> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the >> schematic (p157 of the PDF). >> >> Picture of the failed chip here: >> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg >> >> Can anyone tell me what the best modern equivalent is likely to be? >> >> Thanks >> >> Rob >> > You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. I know LS has less fanout, but is it not able to drive plain 74xx at all? That doesn't sound right. If the circuit in question runs near the fanout spec of plain 74 the yes, 74LS won't work. Spec sheets and the actual schematic will give a definitive answer. paul From g4ajq1 at gmail.com Sat May 14 12:50:14 2022 From: g4ajq1 at gmail.com (Nigel Johnson Ham) Date: Sat, 14 May 2022 13:50:14 -0400 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> Message-ID: <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> AFAIR LS can only drive one unit TTL load. I may have some 7474, even of that vintage, if you cannot find any anywhere else. cheers, Nigel Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 On 2022-05-14 13:48, Paul Koning via cctalk wrote: > >> On May 14, 2022, at 1:41 PM, John Robertson via cctalk wrote: >> >> On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: >>> Hello, >>> >>> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a >>> 7474 D flip flop. The problem is I don't know which modern series >>> would be the best one to replace it with. I am sure I have seen a list >>> somewhere of modern equivalents for some DEC chip numbers, but I can't >>> remember where. >>> >>> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the >>> schematic (p157 of the PDF). >>> >>> Picture of the failed chip here: >>> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg >>> >>> Can anyone tell me what the best modern equivalent is likely to be? >>> >>> Thanks >>> >>> Rob >>> >> You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. > I know LS has less fanout, but is it not able to drive plain 74xx at all? That doesn't sound right. If the circuit in question runs near the fanout spec of plain 74 the yes, 74LS won't work. > > Spec sheets and the actual schematic will give a definitive answer. > > paul > > From bfranchuk at jetnet.ab.ca Sat May 14 17:08:55 2022 From: bfranchuk at jetnet.ab.ca (ben) Date: Sat, 14 May 2022 16:08:55 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> Message-ID: <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: > AFAIR LS can only drive one unit TTL load. >> ????paul LS is 4 TTL, 4 ma low. Was there a trick of forcing the output of D flip flip to clear it? I was wondering if this is what kills all the 7474's? Ben. From dkelvey at hotmail.com Sat May 14 17:35:58 2022 From: dkelvey at hotmail.com (dwight) Date: Sat, 14 May 2022 22:35:58 +0000 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> Message-ID: What ever you do, don't use a Fairchild part. When I worked for Intel in the 80's, we finally band using Fairchild for any latching device. They failed on pullup current, even when the parts were sent back and they claimed they were good. We just gave up on them, we couldn't hold production while they figured it out. We had a similar problem with PowerOne, a manufacture of power supplies. Since it was a custom supply, we had to send someone to their plant to fix their final test. Dwight ________________________________ From: cctalk on behalf of Nigel Johnson Ham via cctalk Sent: Saturday, May 14, 2022 10:50 AM To: Paul Koning via cctalk Subject: Re: Replacement for a DEC 7474 Chip AFAIR LS can only drive one unit TTL load. I may have some 7474, even of that vintage, if you cannot find any anywhere else. cheers, Nigel Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 On 2022-05-14 13:48, Paul Koning via cctalk wrote: > >> On May 14, 2022, at 1:41 PM, John Robertson via cctalk wrote: >> >> On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: >>> Hello, >>> >>> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a >>> 7474 D flip flop. The problem is I don't know which modern series >>> would be the best one to replace it with. I am sure I have seen a list >>> somewhere of modern equivalents for some DEC chip numbers, but I can't >>> remember where. >>> >>> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the >>> schematic (p157 of the PDF). >>> >>> Picture of the failed chip here: >>> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg >>> >>> Can anyone tell me what the best modern equivalent is likely to be? >>> >>> Thanks >>> >>> Rob >>> >> You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. > I know LS has less fanout, but is it not able to drive plain 74xx at all? That doesn't sound right. If the circuit in question runs near the fanout spec of plain 74 the yes, 74LS won't work. > > Spec sheets and the actual schematic will give a definitive answer. > > paul > > From cclist at sydex.com Sat May 14 23:53:26 2022 From: cclist at sydex.com (Chuck Guzis) Date: Sat, 14 May 2022 21:53:26 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> Message-ID: <29b8da99-0c59-250e-5d22-f8654e9dd5fb@sydex.com> On 5/14/22 15:35, dwight via cctalk wrote: >>> You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. >> I know LS has less fanout, but is it not able to drive plain 74xx at all? That doesn't sound right. If the circuit in question runs near the fanout spec of plain 74 the yes, 74LS won't work. >> >> Spec sheets and the actual schematic will give a definitive answer. >> I've got a whole parts drawer full of 74S74s, which I believe exceed the output current capabilities of the original 7474. There's also the 74ABT74, if you want a beefer BiMOS version. Heck, I can probably come up with a couple of crufty old 74H74s... --Chuck From bfranchuk at jetnet.ab.ca Sun May 15 01:04:21 2022 From: bfranchuk at jetnet.ab.ca (ben) Date: Sun, 15 May 2022 00:04:21 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <29b8da99-0c59-250e-5d22-f8654e9dd5fb@sydex.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <29b8da99-0c59-250e-5d22-f8654e9dd5fb@sydex.com> Message-ID: <678e5423-6016-b663-689e-5c1ee16310d9@jetnet.ab.ca> On 2022-05-14 10:53 p.m., Chuck Guzis via cctalk wrote: > On 5/14/22 15:35, dwight via cctalk wrote: > >>>> You are stuck with using an original 7474 family assuming this is driving other early TTL. 74LS74, and others simply don't have the drive capability to work. >>> I know LS has less fanout, but is it not able to drive plain 74xx at all? That doesn't sound right. If the circuit in question runs near the fanout spec of plain 74 the yes, 74LS won't work. >>> >>> Spec sheets and the actual schematic will give a definitive answer. >>> > > I've got a whole parts drawer full of 74S74s, which I believe exceed the > output current capabilities of the original 7474. There's also the > 74ABT74, if you want a beefer BiMOS version. Heck, I can probably come > up with a couple of crufty old 74H74s... > > --Chuck > Faster is not better, bigger is bett... ops wrong topic. 74H while slower, and 74S tend to have reliable delay times looking at gates with min to max delays < 3 ns. This helped devices to track the same speed across a system. A 74ABT00 is 1 to 4 ns depending on the temp,phase of the moon,and what ever. How much margin do I need to add? Ok I guess for connecting a 386? Ben. From cz at alembic.crystel.com Sun May 15 02:42:06 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Sun, 15 May 2022 09:42:06 +0200 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: <67F78269-DDF9-40AA-9F7A-09267C945151@alembic.crystel.com> I'll have to check when I get back from Norway but I believe I replaced thirty or so flip flops with 74ls74 chips with no problems. This was on my pdp8l and granted Dec used a lot of 4 and 8 input nand gates to drive loads On May 15, 2022 12:08:55 AM GMT+02:00, ben via cctalk wrote: >On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: >> AFAIR LS can only drive one unit TTL load. >>> ????paul >LS is 4 TTL, 4 ma low. >Was there a trick of forcing the output of D flip flip >to clear it? I was wondering if this is what kills all >the 7474's? >Ben. > > > -- Sent from my Android device with K-9 Mail. Please excuse my brevity. From robert.jarratt at ntlworld.com Sun May 15 03:04:18 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Sun, 15 May 2022 09:04:18 +0100 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> Message-ID: <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> Oh dear, while I was ordering an original 7474 I ordered some other parts that were connected to the same bad chip in case other chips are damaged, and I ordered a Fairchild 74LS08! I will ask them to change it for a Motorola part they also have. > -----Original Message----- > From: cctalk On Behalf Of dwight via cctalk > Sent: 14 May 2022 23:36 > To: Paul Koning via cctalk > Subject: Re: Replacement for a DEC 7474 Chip > > What ever you do, don't use a Fairchild part. When I worked for Intel in the > 80's, we finally band using Fairchild for any latching device. They failed on > pullup current, even when the parts were sent back and they claimed they > were good. We just gave up on them, we couldn't hold production while > they figured it out. > We had a similar problem with PowerOne, a manufacture of power supplies. > Since it was a custom supply, we had to send someone to their plant to fix > their final test. > Dwight > > > ________________________________ > From: cctalk on behalf of Nigel Johnson > Ham via cctalk > Sent: Saturday, May 14, 2022 10:50 AM > To: Paul Koning via cctalk > Subject: Re: Replacement for a DEC 7474 Chip > > AFAIR LS can only drive one unit TTL load. > > I may have some 7474, even of that vintage, if you cannot find any anywhere > else. > > cheers, > > Nigel > > > Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, > the origin of the open-source concept! > Skype: TILBURY2591 > > > On 2022-05-14 13:48, Paul Koning via cctalk wrote: > > > >> On May 14, 2022, at 1:41 PM, John Robertson via > cctalk wrote: > >> > >> On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: > >>> Hello, > >>> > >>> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a > >>> 7474 D flip flop. The problem is I don't know which > >>> modern series would be the best one to replace it with. I am sure I > >>> have seen a list somewhere of modern equivalents for some DEC chip > >>> numbers, but I can't remember where. > >>> > >>> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 > >>> of the schematic (p157 of the PDF). > >>> > >>> Picture of the failed chip here: > >>> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.j > >>> pg > >>> > >>> Can anyone tell me what the best modern equivalent is likely to be? > >>> > >>> Thanks > >>> > >>> Rob > >>> > >> You are stuck with using an original 7474 family assuming this is driving > other early TTL. 74LS74, and others simply don't have the drive capability to > work. > > I know LS has less fanout, but is it not able to drive plain 74xx at all? That > doesn't sound right. If the circuit in question runs near the fanout spec of > plain 74 the yes, 74LS won't work. > > > > Spec sheets and the actual schematic will give a definitive answer. > > > > paul > > > > From spacewar at gmail.com Sun May 15 03:11:18 2022 From: spacewar at gmail.com (Eric Smith) Date: Sun, 15 May 2022 02:11:18 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> Message-ID: Those should be fine. Only the more complex parts had issues, not the simple gates. On Sun, May 15, 2022, 02:04 Rob Jarratt via cctalk wrote: > Oh dear, while I was ordering an original 7474 I ordered some other parts > that were connected to the same bad chip in case other chips are damaged, > and I ordered a Fairchild 74LS08! I will ask them to change it for a > Motorola part they also have. > > > -----Original Message----- > > From: cctalk On Behalf Of dwight via > cctalk > > Sent: 14 May 2022 23:36 > > To: Paul Koning via cctalk > > Subject: Re: Replacement for a DEC 7474 Chip > > > > What ever you do, don't use a Fairchild part. When I worked for Intel in > the > > 80's, we finally band using Fairchild for any latching device. They > failed > on > > pullup current, even when the parts were sent back and they claimed they > > were good. We just gave up on them, we couldn't hold production while > > they figured it out. > > We had a similar problem with PowerOne, a manufacture of power supplies. > > Since it was a custom supply, we had to send someone to their plant to > fix > > their final test. > > Dwight > > > > > > ________________________________ > > From: cctalk on behalf of Nigel Johnson > > Ham via cctalk > > Sent: Saturday, May 14, 2022 10:50 AM > > To: Paul Koning via cctalk > > Subject: Re: Replacement for a DEC 7474 Chip > > > > AFAIR LS can only drive one unit TTL load. > > > > I may have some 7474, even of that vintage, if you cannot find any > anywhere > > else. > > > > cheers, > > > > Nigel > > > > > > Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, > > the origin of the open-source concept! > > Skype: TILBURY2591 > > > > > > On 2022-05-14 13:48, Paul Koning via cctalk wrote: > > > > > >> On May 14, 2022, at 1:41 PM, John Robertson via > > cctalk wrote: > > >> > > >> On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: > > >>> Hello, > > >>> > > >>> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a > > >>> 7474 D flip flop. The problem is I don't know which > > >>> modern series would be the best one to replace it with. I am sure I > > >>> have seen a list somewhere of modern equivalents for some DEC chip > > >>> numbers, but I can't remember where. > > >>> > > >>> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 > > >>> of the schematic (p157 of the PDF). > > >>> > > >>> Picture of the failed chip here: > > >>> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.j > > >>> pg > > >>> > > >>> Can anyone tell me what the best modern equivalent is likely to be? > > >>> > > >>> Thanks > > >>> > > >>> Rob > > >>> > > >> You are stuck with using an original 7474 family assuming this is > driving > > other early TTL. 74LS74, and others simply don't have the drive > capability > to > > work. > > > I know LS has less fanout, but is it not able to drive plain 74xx at > all? That > > doesn't sound right. If the circuit in question runs near the fanout > spec > of > > plain 74 the yes, 74LS won't work. > > > > > > Spec sheets and the actual schematic will give a definitive answer. > > > > > > paul > > > > > > > > From spacewar at gmail.com Sun May 15 03:16:57 2022 From: spacewar at gmail.com (Eric Smith) Date: Sun, 15 May 2022 02:16:57 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: On Sat, May 14, 2022, 16:09 ben via cctalk wrote: > On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: > > AFAIR LS can only drive one unit TTL load. > >> paul > LS is 4 TTL, 4 ma low. > Was there a trick of forcing the output of D flip flip > to clear it? I was wondering if this is what kills all > the 7474's? > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except maybe by accident if you shorted the output enough to draw Vcc down (or ground up) enough to disrupt the FF, and then you have other problems. Despite the logic diagram showing feedback from the outputs, all 74x74 have buffered outputs. The recent TI data sheets show an equivalent schematic only for the 74LS74. I can't at the moment find one for the 7474. It seems likely to me that early pre-TTL logic families like RTL might have had FFs with unbuffered outputs, but I haven't checked. From cclist at sydex.com Sun May 15 09:57:13 2022 From: cclist at sydex.com (Chuck Guzis) Date: Sun, 15 May 2022 07:57:13 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <678e5423-6016-b663-689e-5c1ee16310d9@jetnet.ab.ca> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <29b8da99-0c59-250e-5d22-f8654e9dd5fb@sydex.com> <678e5423-6016-b663-689e-5c1ee16310d9@jetnet.ab.ca> Message-ID: On 5/14/22 23:04, ben via cctalk wrote: > Faster is not better, bigger is bett... ops wrong topic. > > 74H while slower, and 74S tend to have reliable delay times looking at > gates with min to max delays < 3 ns. This helped devices to track > the same speed across a system. > A 74ABT00 is 1 to 4 ns depending on the temp,phase of the moon,and what > ever. How much margin do I need to add? Ok I guess for connecting a 386? Sure, but if the concern was output sink current, the S or AS family can certainly provide it. It all depends on the position of the IC in the circuitry. Depending on application, you might conceivably get away with a 74HC74; that is some parameters may not matter. I might still have a couple of DM7474's kicking around, but they're so old, I wouldn't depend on them. I even have a few Fairchild 74F74s... --Chuck From cclist at sydex.com Sun May 15 10:11:42 2022 From: cclist at sydex.com (Chuck Guzis) Date: Sun, 15 May 2022 08:11:42 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: On 5/15/22 01:16, Eric Smith via cctalk wrote: > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > maybe by accident if you shorted the output enough to draw Vcc down (or > ground up) enough to disrupt the FF, and then you have other problems. Checking my old Moto databook, the old FFs appear to be capable of having the outputs jammed. At first glance, both the 7472 and 7473 FFs had unbuffered outputs. Most early latches, likewise. Of course, the very early TTL was density-constrained, so FFs like the MC512/MC563 are of course without buffered outputs. --Chuck From dave.g4ugm at gmail.com Sun May 15 10:47:42 2022 From: dave.g4ugm at gmail.com (dave.g4ugm at gmail.com) Date: Sun, 15 May 2022 16:47:42 +0100 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: <04d801d86873$1dbd69b0$59383d10$@gmail.com> Folks, I probably have some, and now I have found my ICL House Codes sheet I may even be able to identify them. However I won't be in the same country as my stock for a couple of weeks..... ... and they are in the UK so getting them stateside may take some time. Dave G4UGM > -----Original Message----- > From: cctalk On Behalf Of Chuck Guzis via > cctalk > Sent: 15 May 2022 16:12 > To: cctalk at classiccmp.org > Subject: Re: Replacement for a DEC 7474 Chip > > On 5/15/22 01:16, Eric Smith via cctalk wrote: > > > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, > > except maybe by accident if you shorted the output enough to draw Vcc > > down (or ground up) enough to disrupt the FF, and then you have other > problems. > > Checking my old Moto databook, the old FFs appear to be capable of > having the outputs jammed. At first glance, both the 7472 and 7473 FFs > had unbuffered outputs. Most early latches, likewise. > > Of course, the very early TTL was density-constrained, so FFs like the > MC512/MC563 are of course without buffered outputs. > > --Chuck From cisin at xenosoft.com Sun May 15 10:57:10 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Sun, 15 May 2022 08:57:10 -0700 (PDT) Subject: Replacement for a DEC 7474 Chip In-Reply-To: <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> Message-ID: > What ever you do, don't use a Fairchild part. When I worked for Intel in > the 80's, we finally band using Fairchild for any latching device. They > failed on pullup current, even when the parts were sent back and they > claimed they were good. We just gave up on them, we couldn't hold > production while they figured it out. > We had a similar problem with PowerOne, a manufacture of power supplies. I've heard the same thing about Intel, Shugart, Verbatim, Wabash, Tandy, Apple, Commodore, VW, Ford, Chevy, . . . Just about EVERY company has released a bad product, and had their reputation damaged. A better warning is: "Between xxx and yyy, we had a lot of bad parts from zzz." SOME have cleaned up their act, and have made good products subsequently. From syseng at gfsys.co.uk Sun May 15 13:51:55 2022 From: syseng at gfsys.co.uk (Chris Quayle) Date: Sun, 15 May 2022 19:51:55 +0100 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: Message-ID: <62814BCB.7030609@gfsys.co.uk> On 05/15/22 18:00, cctech-request at classiccmp.org wrote: > Send cctech mailing list submissions to > cctech at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctech > or, via email, send a message with subject or body 'help' to > cctech-request at classiccmp.org > > You can reach the person managing the list at > cctech-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctech digest..." > > > Today's Topics: > > 1. Replacement for a DEC 7474 Chip (Rob Jarratt) > 2. Re: Replacement for a DEC 7474 Chip (John Robertson) > 3. Re: Replacement for a DEC 7474 Chip (Paul Koning) > 4. Re: Replacement for a DEC 7474 Chip (Nigel Johnson Ham) > 5. Re: Replacement for a DEC 7474 Chip (ben) > 6. Re: Replacement for a DEC 7474 Chip (Chuck Guzis) > 7. Re: Replacement for a DEC 7474 Chip (ben) > 8. Re: Replacement for a DEC 7474 Chip (dwight) > 9. Re: Replacement for a DEC 7474 Chip (Chris Zach) > 10. RE: Replacement for a DEC 7474 Chip (Rob Jarratt) > 11. Re: Replacement for a DEC 7474 Chip (Eric Smith) > 12. Re: Replacement for a DEC 7474 Chip (Eric Smith) > 13. Re: Replacement for a DEC 7474 Chip (Chuck Guzis) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 14 May 2022 18:11:32 +0100 > From: "Rob Jarratt" > To: "General Discussion: On-Topic and Off-Topic Posts" > > Subject: Replacement for a DEC 7474 Chip > Message-ID:<007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> > Content-Type: text/plain; charset="us-ascii" > > Hello, > > > > I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a > 7474 D flip flop. The problem is I don't know which modern series > would be the best one to replace it with. I am sure I have seen a list > somewhere of modern equivalents for some DEC chip numbers, but I can't > remember where. > > > > If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the > schematic (p157 of the PDF). > > > > Picture of the failed chip here: > https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg > > > > Can anyone tell me what the best modern equivalent is likely to be? > > > > Thanks > > > > Rob > > > > ------------------------------ > > Message: 2 > Date: Sat, 14 May 2022 10:41:34 -0700 > From: John Robertson > To: Rob Jarratt via cctalk > Subject: Re: Replacement for a DEC 7474 Chip > Message-ID: > Content-Type: text/plain; charset=UTF-8; format=flowed > > On 2022/05/14 10:11 a.m., Rob Jarratt via cctalk wrote: >> Hello, >> >> I have found a bad DEC 7474 chip on my M7133 board. Clearly it is a >> 7474 D flip flop. The problem is I don't know which modern series >> would be the best one to replace it with. I am sure I have seen a list >> somewhere of modern equivalents for some DEC chip numbers, but I can't >> remember where. >> >> If it helps at all, on the PDP 11/24 printset it is E78 on page K6 of the >> schematic (p157 of the PDF). >> >> Picture of the failed chip here: >> https://rjarratt.files.wordpress.com/2022/05/damaged-dec-7474-4_li.jpg >> >> Can anyone tell me what the best modern equivalent is likely to be? >> >> Thanks >> >> Rob >> > You are stuck with using an original 7474 family assuming this is > driving other early TTL. 74LS74, and others simply don't have the drive > capability to work. You can use 74S74 or 74F74 as they have the same > output current, the "S" is Schottky, and the other is "F"aster. > > I find that https:///unicornelectronics.com is a reliable source of TTL. > > John :-#)# > Original 74 series TTL can still be found, Ebay often, new old stock and other surplus vendors. Would need to take care replacing with later ttl series, as the gate delay, switching times and fanout probably won't match. Always use the original series if you can... Chris From bhilpert at shaw.ca Sun May 15 14:02:56 2022 From: bhilpert at shaw.ca (Brent Hilpert) Date: Sun, 15 May 2022 12:02:56 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: On 2022-May-15, at 1:16 AM, Eric Smith via cctalk wrote: > On Sat, May 14, 2022, 16:09 ben via cctalk wrote: >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: >>> AFAIR LS can only drive one unit TTL load. >>>> paul >> LS is 4 TTL, 4 ma low. >> Was there a trick of forcing the output of D flip flip >> to clear it? I was wondering if this is what kills all >> the 7474's? > > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > maybe by accident if you shorted the output enough to draw Vcc down (or > ground up) enough to disrupt the FF, and then you have other problems. > > Despite the logic diagram showing feedback from the outputs, all 74x74 have > buffered outputs. Per TI schematics from 1969: 74 standard, H and L series flip-flops are unbuffered. Or at least many of them are/were, in their then-original form. Including 7475, 7490, etc. The output transistors connect both to the pins and wrap back to form the FF or other purposes. Collector-triggering was discussed a some years ago on the list in regards to a pdp8 front panel where DEC used collector-triggering on 74175's (IMO, bad design practice). From (my) empirical tests at the time, it turned out some 74S (Schottky) parts could be collector-triggered. However, between standard, LS, and S types, behaviour could vary with manufacturer and production date. > The recent TI data sheets show an equivalent schematic > only for the 74LS74. I can't at the moment find one for the 7474. > It seems likely to me that early pre-TTL logic families like RTL might have > had FFs with unbuffered outputs, but I haven't checked. From paulkoning at comcast.net Sun May 15 13:55:56 2022 From: paulkoning at comcast.net (Paul Koning) Date: Sun, 15 May 2022 14:55:56 -0400 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <62814BCB.7030609@gfsys.co.uk> References: <62814BCB.7030609@gfsys.co.uk> Message-ID: <98B5E857-2395-42DB-AFF0-A7B5660FDCED@comcast.net> > On May 15, 2022, at 2:51 PM, Chris Quayle via cctech wrote: > > ... > Original 74 series TTL can still be found, Ebay often, new old stock > and other surplus vendors. > > Would need to take care replacing with later ttl series, as the gate > delay, switching times and fanout probably won't match. Always use the > original series if you can... That's sensible advice. When you can't, faster devices with adequate fanout should work. The exception would be in circuits with hairy timing, where the design relies on the actual stage delays of the components. Most people don't build that way, for good reason. Seymour Cray is the best known exception; for example, the CDC 6600 design is very thoroughly dependent on the circuit and wire delays, and either slower OR faster will break things. And actually, it isn't clear to me why the thing ever works; the design files clearly demonstrate clashing signals that somehow apparently don't show up in reality. paul From echristopherson at gmail.com Sun May 15 15:56:40 2022 From: echristopherson at gmail.com (Eric Christopherson) Date: Sun, 15 May 2022 15:56:40 -0500 Subject: Cctalk subscription disabled In-Reply-To: <047f01d8657b$067f79f0$137e6dd0$@gmail.com> References: <005301d86531$167f3d30$437db790$@classiccmp.org> <047f01d8657b$067f79f0$137e6dd0$@gmail.com> Message-ID: On Wed, May 11, 2022, 4:06 PM Dave Wade G4UGM via cctalk < cctalk at classiccmp.org> wrote: > Jay, > Thanks for that, I hope its fixed, > Dave > G4UGM > > > -----Original Message----- > > From: cctalk On Behalf Of jwest--- via > > cctalk > > Sent: 11 May 2022 13:18 > > To: 'Tom Hunter' ; 'Adrian Stoness' > > ; cctalk-owner at classiccmp.org > > Cc: 'General Discussion: On-Topic and Off-Topic Posts' > > > > Subject: RE: Cctalk subscription disabled > > > > Yes, Adrian is correct ? known for some time but my time/focus has been > > elsewhere. Addressed yesterday, should make gmail less fussy. > Jay, You may also want to look at the timing the list software uses for deciding when to notify people they've had excessive bounces; I got this on April *24*, fully two weeks after I stopped getting messages; a similar thing happened on March 21, but that one was only one week late: Your membership in the mailing list cctalk has been disabled due to excessive bounces The last bounce received from you was dated 10-Apr-2022. You will not get any more messages from this list until you re-enable your membership. You will receive 1 more reminders like this before your membership in the list is deleted. > > > > > > > J > > > > > > > > From: cctalk On Behalf Of Tom Hunter > > Sent: Wednesday, May 11, 2022 7:06 AM > > To: Adrian Stoness ; cctalk-owner at classiccmp.org > > Cc: General Discussion: On-Topic and Off-Topic Posts > > > > Subject: Re: Cctalk subscription disabled > > > > > > > > I wonder if this problem is related to DMARC anti-spam. > > > > Maybe the following would help the list admin: > > > > > > > > https://wiki.list.org/DEV/DMARC > > > > https://dmarc.org/wiki/FAQ > > > > > > > > Thanks > > > > Tom > > > > > > > > On Wed, May 11, 2022 at 2:26 PM Adrian Stoness > > wrote: > > > > gmail is causing it > > > > > > > > On Wed, May 11, 2022 at 1:15 AM Tom Hunter via cctalk > > > wrote: > > > > I didn't receive any cctalk messages for a few days, so I checked my Spam > > folder (empty) and then the archive which had several new messages I > > haven't seen. I then checked my cctalk membership configuration. > > Surprisingly "Mail delivery" was disabled. > > > > Some time ago I received a few emails from the list server about > "excessive > > bounces" saying that I should simply reply to the email otherwise my > > subscription would be disabled. I replied and didn't think too much > about it. > > This time I got no "excessive bounces" email but my subscription got > > disabled. > > > > I got an otherwise reliable @gmail.com email > address. > > Does anyone else here have problems with this? Is there some way of > > preventing this from happening? > > > > Thanks > > Tom -- Eric Christopherson From drb at msu.edu Sun May 15 17:26:26 2022 From: drb at msu.edu (Dennis Boone) Date: Sun, 15 May 2022 18:26:26 -0400 Subject: Cctalk subscription disabled In-Reply-To: (Your message of Sun, 15 May 2022 15:56:40 -0500.) References: <005301d86531$167f3d30$437db790$@classiccmp.org> <047f01d8657b$067f79f0$137e6dd0$@gmail.com> Message-ID: <20220515222626.4DDC13FE82C@yagi.h-net.msu.edu> > You may also want to look at the timing the list software uses for > deciding when to notify people they've had excessive bounces; I got > this on April *24*, fully two weeks after I stopped getting messages; > a similar thing happened on March 21, but that one was only one week > late: Modern anti-spam measures, especially google's, have gotten fairly non-deterministic, at least to outward inspection. It is especially difficult to reason about delivery timing. For example, the list server may well have had the notice in queue trying to get google to accept it for a number of days. Google is known to hold things for several days, progressively showing them to a few more people, until it decides whether they're spam or not. A single-address notice wouldn't seem to be a candidate for that behavior, but _I_ wouldn't bet any money against google comparing such a single-address message against other singles that were statistically (or machine-learning-y) similar. Yes, two weeks seems long, but if a number of list posts were queued up on the list server not getting delivered to you for some days, and google deferred some of them, and google deferred the notice, and google held the notice after accepting it, that could actually pretty easily add up to more than two weeks. Mailman sends the notice at the point it makes the decision. There are some knobs for how many bounces over what time period result in action. De From spacewar at gmail.com Sun May 15 17:53:33 2022 From: spacewar at gmail.com (Eric Smith) Date: Sun, 15 May 2022 16:53:33 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: I specifically said 74x74. Early TTL flipflops were very crude by comparison. On Sun, May 15, 2022, 13:03 Brent Hilpert via cctalk wrote: > On 2022-May-15, at 1:16 AM, Eric Smith via cctalk wrote: > > On Sat, May 14, 2022, 16:09 ben via cctalk > wrote: > >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: > >>> AFAIR LS can only drive one unit TTL load. > >>>> paul > >> LS is 4 TTL, 4 ma low. > >> Was there a trick of forcing the output of D flip flip > >> to clear it? I was wondering if this is what kills all > >> the 7474's? > > > > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > > maybe by accident if you shorted the output enough to draw Vcc down (or > > ground up) enough to disrupt the FF, and then you have other problems. > > > > Despite the logic diagram showing feedback from the outputs, all 74x74 > have > > buffered outputs. > > Per TI schematics from 1969: 74 standard, H and L series flip-flops are > unbuffered. Or at least many of them are/were, in their then-original form. > Including 7475, 7490, etc. The output transistors connect both to the pins > and wrap back to form the FF or other purposes. > > Collector-triggering was discussed a some years ago on the list in regards > to a pdp8 front panel where DEC used collector-triggering on 74175's (IMO, > bad design practice). From (my) empirical tests at the time, it turned out > some 74S (Schottky) parts could be collector-triggered. However, between > standard, LS, and S types, behaviour could vary with manufacturer and > production date. > > > > The recent TI data sheets show an equivalent schematic > > only for the 74LS74. I can't at the moment find one for the 7474. > > > It seems likely to me that early pre-TTL logic families like RTL might > have > > had FFs with unbuffered outputs, but I haven't checked. > > From bitwiz at 12bitsbest.com Sun May 15 19:30:15 2022 From: bitwiz at 12bitsbest.com (Mike Katz) Date: Sun, 15 May 2022 19:30:15 -0500 Subject: PDP-8 Memory In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <00ab01d86832$609969f0$21cc3dd0$@ntlworld.com> Message-ID: <9457f678-b934-a10a-8033-2fdb0bae5d72@12bitsbest.com> I have recently acquired a PDP-8/A to go with my PDP-8/E. Unfortunately it came with the industrial front panel and not the programmers panel. Does any one have an extra PDP-8/A programmers panel they can spare? Also, does any one have any PDP-8/A memory they can spare (or any Omnibus memory). Thanks, ?????? Mike From ball.of.john at gmail.com Sun May 15 23:02:52 2022 From: ball.of.john at gmail.com (John Ball) Date: Sun, 15 May 2022 21:02:52 -0700 Subject: Identifying an 1802 system In-Reply-To: Message-ID: <6549175092B2414D90D66F5CE10F82C2@Sparks> I just received a machine that someone found at a Vancouver second hand store that I basically told them to buy on the single fact I don't own any COSMAC machines and I've now had a chance to take it apart and photograph the boards. It seems to be some sort of a kit system that the previous owner put into a custom enclosure along with a power supply, a cassette interface and the keyboard off of some other machine or terminal I can't identify but the interfacing absolutely screams it was something they had available from scrap. It's 1802 based, has a single 2716 EPROM and a pair of Intersil D2114 1024 x 4 SRAM chips. The keyboard interfaces through a CDP1851 PIO. The other board on the almost empty backplane was a video board and this is what made me think it's not just a fancy ELF clone. You have six more 2114's and an MC6847 video display generator. The output of that seems to go to an RF modulator-on-a-chip and then out to an F-type coax. The cassette interface is soldered directly to the backplane but its edge connector pinout is awfully similar to the Commodre C2N interface. The boards are all nicely made photo etch with drilled and plated vias which leads me to believe this was a purchased kit system and the chips all date to between 1979 and 1982 but the one thing I am missing is a brand or trademark so I don't even know what I'm looking at. The only thing I got to go on is the name "Color Machine" which I have not yet found anything about. I have not yet had a chance to dump the EPROM and I'm still testing to make sure nothing will blow up in a smoke test, plus I need to dig out a monitor with RF. I have posted board photos over in https://forum.vcfed.org/index.php?threads/unknown-1802-based-system.1237931/ post-1256906 in the hopes someone recognizes it but does this look familiar to anyone here? -John From wrcooke at wrcooke.net Mon May 16 08:22:56 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Mon, 16 May 2022 08:22:56 -0500 (CDT) Subject: Identifying an 1802 system In-Reply-To: <6549175092B2414D90D66F5CE10F82C2@Sparks> References: <6549175092B2414D90D66F5CE10F82C2@Sparks> Message-ID: <439859903.5376351.1652707376559@email.ionos.com> > On 05/15/2022 11:02 PM John Ball via cctech wrote: > > > I just received a machine that someone found at a Vancouver second hand > store that I basically told them to buy on the single fact I don't own any > COSMAC machines and I've now had a chance to take it apart and photograph > the boards. It seems to be some sort of a kit system that the previous owner > put into a custom enclosure along with a power supply, a cassette interface I suggest asking over at cosmacelf.com. There is a lot of Cosmac info and expertise there, not just about Elfs (elves?). One thing that comes to mind is a series of boards and kits that were developed by a Canadian user group that sounds much like you describe. Development of those were tracked in their newsletter, Ipso Facto: http://cosmacelf.com/publications/newsletters/ipso-facto/ Some of the people who developed those systems are members of the forum at cosmacelf.com. Will From wrcooke at wrcooke.net Mon May 16 08:22:56 2022 From: wrcooke at wrcooke.net (wrcooke at wrcooke.net) Date: Mon, 16 May 2022 08:22:56 -0500 (CDT) Subject: Identifying an 1802 system In-Reply-To: <6549175092B2414D90D66F5CE10F82C2@Sparks> References: <6549175092B2414D90D66F5CE10F82C2@Sparks> Message-ID: <439859903.5376351.1652707376559@email.ionos.com> > On 05/15/2022 11:02 PM John Ball via cctech wrote: > > > I just received a machine that someone found at a Vancouver second hand > store that I basically told them to buy on the single fact I don't own any > COSMAC machines and I've now had a chance to take it apart and photograph > the boards. It seems to be some sort of a kit system that the previous owner > put into a custom enclosure along with a power supply, a cassette interface I suggest asking over at cosmacelf.com. There is a lot of Cosmac info and expertise there, not just about Elfs (elves?). One thing that comes to mind is a series of boards and kits that were developed by a Canadian user group that sounds much like you describe. Development of those were tracked in their newsletter, Ipso Facto: http://cosmacelf.com/publications/newsletters/ipso-facto/ Some of the people who developed those systems are members of the forum at cosmacelf.com. Will From rick at rickmurphy.net Mon May 16 11:27:30 2022 From: rick at rickmurphy.net (Rick Murphy) Date: Mon, 16 May 2022 12:27:30 -0400 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: <448f1c4e-a48e-1588-aaa1-135cbbf5f0d0@rickmurphy.net> On 5/15/2022 4:16 AM, Eric Smith via cctalk wrote: > On Sat, May 14, 2022, 16:09 ben via cctalk wrote: > >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: >>> AFAIR LS can only drive one unit TTL load. >>>> paul >> LS is 4 TTL, 4 ma low. >> Was there a trick of forcing the output of D flip flip >> to clear it? I was wondering if this is what kills all >> the 7474's? >> > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > maybe by accident if you shorted the output enough to draw Vcc down (or > ground up) enough to disrupt the FF, and then you have other problems. > > Despite the logic diagram showing feedback from the outputs, all 74x74 have > buffered outputs. The recent TI data sheets show an equivalent schematic > only for the 74LS74. I can't at the moment find one for the 7474. > > It seems likely to me that early pre-TTL logic families like RTL might have > had FFs with unbuffered outputs, but I haven't checked. I have several 7474s, including one marked DEC 7474. Sadly, I fear that shipping from the US is likely to be prohibitive. ??? -Rick From bhilpert at shaw.ca Mon May 16 12:28:19 2022 From: bhilpert at shaw.ca (Brent Hilpert) Date: Mon, 16 May 2022 10:28:19 -0700 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: On 2022-May-15, at 3:53 PM, Eric Smith wrote: > On Sun, May 15, 2022, 13:03 Brent Hilpert via cctalk wrote: > On 2022-May-15, at 1:16 AM, Eric Smith via cctalk wrote: > > On Sat, May 14, 2022, 16:09 ben via cctalk wrote: > >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: > >>> AFAIR LS can only drive one unit TTL load. > >>>> paul > >> LS is 4 TTL, 4 ma low. > >> Was there a trick of forcing the output of D flip flip > >> to clear it? I was wondering if this is what kills all > >> the 7474's? > > > > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, except > > maybe by accident if you shorted the output enough to draw Vcc down (or > > ground up) enough to disrupt the FF, and then you have other problems. > > > > Despite the logic diagram showing feedback from the outputs, all 74x74 have > > buffered outputs. > > Per TI schematics from 1969: 74 standard, H and L series flip-flops are unbuffered. Or at least many of them are/were, in their then-original form. Including 7475, 7490, etc. The output transistors connect both to the pins and wrap back to form the FF or other purposes. > > Collector-triggering was discussed a some years ago on the list in regards to a pdp8 front panel where DEC used collector-triggering on 74175's (IMO, bad design practice). From (my) empirical tests at the time, it turned out some 74S (Schottky) parts could be collector-triggered. However, between standard, LS, and S types, behaviour could vary with manufacturer and production date. > > > > The recent TI data sheets show an equivalent schematic > > only for the 74LS74. I can't at the moment find one for the 7474. > > > It seems likely to me that early pre-TTL logic families like RTL might have > > had FFs with unbuffered outputs, but I haven't checked. > I specifically said 74x74. Early TTL flipflops were very crude by comparison. S = { "", "L", "H", "S", "LS", "F", "AS", "ALS", "AC", "ABT", etc. } x ? S "", "L", "H", "S" ? S "L", "H", "S" != "" 7474: x == "" pre-TTL != early TTL From spacewar at gmail.com Mon May 16 14:50:04 2022 From: spacewar at gmail.com (Eric Smith) Date: Mon, 16 May 2022 13:50:04 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: On 2022-May-15, at 3:53 PM, Eric Smith wrote: > I specifically said 74x74. Early TTL flipflops were very crude by comparison. On Mon, May 16, 2022 at 11:28 AM Brent Hilpert via cctalk < cctalk at classiccmp.org> wrote: > pre-TTL != early TTL > No, but 7470, 7472, 7473, and 74948 were _very_ early and were also very crude, as were their later L and H variants. 7474 was slightly later, and less crude. It should also be noted that the 7400 series was NOT the first commerical TTL integrated circuits. The earlier TTL flip-flops were even more crude, but I imagine the engineers that used them were nevertheless delighted at the advance over RTL and DTL. From robert.jarratt at ntlworld.com Mon May 16 15:59:40 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Mon, 16 May 2022 21:59:40 +0100 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <448f1c4e-a48e-1588-aaa1-135cbbf5f0d0@rickmurphy.net> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> <448f1c4e-a48e-1588-aaa1-135cbbf5f0d0@rickmurphy.net> Message-ID: <010e01d86967$dc92dd30$95b89790$@ntlworld.com> > -----Original Message----- > From: cctalk On Behalf Of Rick Murphy via > cctalk > Sent: 16 May 2022 17:28 > To: cctalk at classiccmp.org > Subject: Re: Replacement for a DEC 7474 Chip > > On 5/15/2022 4:16 AM, Eric Smith via cctalk wrote: > > On Sat, May 14, 2022, 16:09 ben via cctalk wrote: > > > >> On 2022-05-14 11:50 a.m., Nigel Johnson Ham via cctalk wrote: > >>> AFAIR LS can only drive one unit TTL load. > >>>> paul > >> LS is 4 TTL, 4 ma low. > >> Was there a trick of forcing the output of D flip flip to clear it? I > >> was wondering if this is what kills all the 7474's? > >> > > I don't think that worked on any TTL (or CMOS) 74x74 flip flops, > > except maybe by accident if you shorted the output enough to draw Vcc > > down (or ground up) enough to disrupt the FF, and then you have other > problems. > > > > Despite the logic diagram showing feedback from the outputs, all 74x74 > > have buffered outputs. The recent TI data sheets show an equivalent > > schematic only for the 74LS74. I can't at the moment find one for the 7474. > > > > It seems likely to me that early pre-TTL logic families like RTL might > > have had FFs with unbuffered outputs, but I haven't checked. > > I have several 7474s, including one marked DEC 7474. Sadly, I fear that > shipping from the US is likely to be prohibitive. I have ordered some 7474s. However I am getting a bit lost in the discussion now. From a simple fan out point of view, would an S be sufficient to replace it? > > -Rick From paulkoning at comcast.net Mon May 16 16:08:13 2022 From: paulkoning at comcast.net (Paul Koning) Date: Mon, 16 May 2022 17:08:13 -0400 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <010e01d86967$dc92dd30$95b89790$@ntlworld.com> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> <448f1c4e-a48e-1588-aaa1-135cbbf5f0d0@rickmurphy.net> <010e01d86967$dc92dd30$95b89790$@ntlworld.com> Message-ID: <5330B598-E22F-4AF3-9D91-9E53BEF15584@comcast.net> > On May 16, 2022, at 4:59 PM, Rob Jarratt via cctalk wrote: > >> I have several 7474s, including one marked DEC 7474. Sadly, I fear that >> shipping from the US is likely to be prohibitive. > > I have ordered some 7474s. However I am getting a bit lost in the discussion now. From a simple fan out point of view, would an S be sufficient to replace it? I can think of two ways to answer that: (1) ask and see if you get an answer, hopefullly a correct one, (2) find the data sheet for the 74x74 you're looking at, and the devices it is driving, and do the calculation. Sum up the max input currents of the driven devices, compare with the min output current of the 74x74. If the output current is >= the load current, you have the needed fanout. paul From cube1 at charter.net Mon May 16 16:52:32 2022 From: cube1 at charter.net (Jay Jaeger) Date: Mon, 16 May 2022 16:52:32 -0500 Subject: An IBM 1410 puzzlement... Message-ID: <6807dc15-ab21-1b60-2fd5-7724c593c668@charter.net> I have a puzzlement with my IBM 1410 FPGA implementation. ALD page 42.10.10.1, ILD figure 89 The symptom is this: The CPU runs and can execute instructions. So, stuff is generally working. Starting the address set process, the console appropriately prints the "B" prompt (to set the instruction address into the IAR, B means "BRANCH") or the "#" prompt to set other addresses. Normal stops print the "S" as expected, errors print the "E" as expected and single cycle or I/E mode print the "C" as expected. However, starting a display operation (to display memory), which ought to print a "D", prints an invalid parity "F" character - Bit 2 is picked when it should not be. I have verified that "-S Special Char B" is active (active low) I first saw this on real FPGA hardware, and then confirmed it / did some troubleshooting under simulation. Here is what I found: Looking at the ALD, a "D" is printed when +S ADDRESS SET ROUTINE is active +S DISPLAY ROUTINE is active The Console Matrix at position 30 or 35 All of those conditions are satisfied. Address Set is appropriately active because a display operation starts off by entering an address (even though I don't have console input implemented yet, that is not involved at this point). And, indeed "-S SPECIAL CHAR D" is active (active low), as expected. Looking at the ALD, a "B" is printed when + +S ADDRESS SET ROUTINE is active + The console's address set select rotary switch is NORMAL (it is) (It will print '#' for other positions of this switch) The Console Matrix at position 30 or 35 And, indeed, all of these conditions are satisfied as well, and indeed "-S SPECIAL CHAR B" is active (active low) as well. The FE instructional materials confirm that ADDRESS SET ROUTINE should be active when starting a display operation, consistent with the ALD and the ILD - because both then proceed to allow the operator to input an address. So, this feels like a bug - an implementation error that was later corrected. The ALD I have is pretty early - 6-15-1961, with just one ECO, and that ECO ("B") isn't on any of the gates on that ALD (this is not unusual), so this is probably essentially the original ALD. The fix would be pretty easy: to include "+S DISPLAY ROUTINE" onto the wired or / "DOT" at coordinate 1B (to inhibit "B") and also to add a wired or / "DOT" with "+S DISPLAY ROUTINE" at the output of gate 2I. In both cases, the signal "+S DISPLAY ROUTINE" would then inhibit the "B" or "#" (depending upon how the relevant switch is set.) But I'm just really surprised at the whole thing. Not really asking anyone to do anything, necessarily, but if anyone wants to confirm I'm not nuts (or demonstrate to me that I am nuts), feel free. [I am also experiencing it printing a "." when the mode switch is in CE, which isn't right either - but haven't looked at that. It should be printing a "#", regardless of the setting of the Address Entry switch - I won't be surprised if the same kind of thing is going on there, as this also involves the "address set routine" and matrix position 35 - and a "." is a "#" plus bits B and A - so the evidence is pretty strong there] The documents: 1415 Console CE: http://bitsavers.org/pdf/ibm/1410/CE_Instruction_Reference_Maintenance/1415_Console/ ILD (see Figure 89, page 95 of the PDF below) [ILDs read pretty much like modern logic diagrams] http://bitsavers.org/pdf/ibm/1410/drawings/R23-2936-0_1410_InstructionalLogicDiagrams.pdf The ALD 42.10.10.1 (page 60 of the PDF below) [ALDs are tricker, because of "DOT-ted" connections, and the logic family (RTL NAND *mostly*). http://bitsavers.org/pdf/ibm/1410/drawings/1410_SYSTEM_VOL_X.pdf JRJ From robert.jarratt at ntlworld.com Mon May 16 16:52:34 2022 From: robert.jarratt at ntlworld.com (Rob Jarratt) Date: Mon, 16 May 2022 22:52:34 +0100 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <5330B598-E22F-4AF3-9D91-9E53BEF15584@comcast.net> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> <448f1c4e-a48e-1588-aaa1-135cbbf5f0d0@rickmurphy.net> <010e01d86967$dc92dd30$95b89790$@ntlworld.com> <5330B598-E22F-4AF3-9D91-9E53BEF15584@comcast.net> Message-ID: <011d01d8696f$401b31c0$c0519540$@ntlworld.com> You are right, I thought I remembered someone else saying on this thread that he couldn't find a datasheet for the 7474 so I didn't look, but actually I found one quite easily! From: Paul Koning Sent: 16 May 2022 22:08 To: rob at jarratt.me.uk; Robert Jarratt ; cctalk at classiccmp.org Cc: Rick Murphy Subject: Re: Replacement for a DEC 7474 Chip On May 16, 2022, at 4:59 PM, Rob Jarratt via cctalk > wrote: I have several 7474s, including one marked DEC 7474. Sadly, I fear that shipping from the US is likely to be prohibitive. I have ordered some 7474s. However I am getting a bit lost in the discussion now. From a simple fan out point of view, would an S be sufficient to replace it? I can think of two ways to answer that: (1) ask and see if you get an answer, hopefullly a correct one, (2) find the data sheet for the 74x74 you're looking at, and the devices it is driving, and do the calculation. Sum up the max input currents of the driven devices, compare with the min output current of the 74x74. If the output current is >= the load current, you have the needed fanout. paul From bfranchuk at jetnet.ab.ca Tue May 17 01:35:05 2022 From: bfranchuk at jetnet.ab.ca (ben) Date: Tue, 17 May 2022 00:35:05 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> Message-ID: <73546bba-2a59-1b5f-8f8f-3a17a71dcd71@jetnet.ab.ca> On 2022-05-16 1:50 p.m., Eric Smith via cctalk wrote: > On 2022-May-15, at 3:53 PM, Eric Smith wrote: >> I specifically said 74x74. Early TTL flipflops were very crude by > comparison. > > On Mon, May 16, 2022 at 11:28 AM Brent Hilpert via cctalk < > cctalk at classiccmp.org> wrote: > >> pre-TTL != early TTL >> > > No, but 7470, 7472, 7473, and 74948 were _very_ early and were also very > crude, as were their later L and H variants. 7474 was slightly later, and > less crude. > > It should also be noted that the 7400 series was NOT the first commerical > TTL integrated circuits. The earlier TTL flip-flops were even more crude, > but I imagine the engineers that used them were nevertheless delighted at > the advance over RTL and DTL. Did DEC not use a few Non TTL chips to reduce I/O loading on the bufferd lines? Ben. From spacewar at gmail.com Tue May 17 10:47:55 2022 From: spacewar at gmail.com (Eric Smith) Date: Tue, 17 May 2022 09:47:55 -0600 Subject: Replacement for a DEC 7474 Chip In-Reply-To: <73546bba-2a59-1b5f-8f8f-3a17a71dcd71@jetnet.ab.ca> References: <007b01d867b5$a8c90f00$fa5b2d00$@ntlworld.com> <27A923A9-BEF5-478A-A8F7-5A10E3867E94@comcast.net> <8a91f8a7-5d85-fdb8-5ee8-f3d8f40cfad9@gmail.com> <371dd71e-537a-e9da-d6ae-6f9b8c8135b8@jetnet.ab.ca> <73546bba-2a59-1b5f-8f8f-3a17a71dcd71@jetnet.ab.ca> Message-ID: On Tue, May 17, 2022 at 12:35 AM ben via cctalk wrote: > Did DEC not use a few Non TTL chips to reduce I/O loading on the bufferd > lines? > DEC used non-TTL buffer chips for bus interface (Omnibus, Unibus, Qbus, and external buses like Massbus). Most of the other SSI/MSI logic chips are TTL or TTL-compatible. TTL buffers were usually used where higher fanout was needed on a module, or on non-bus backplane connections. From lee.gleason at comcast.net Tue May 17 12:27:57 2022 From: lee.gleason at comcast.net (Lee Gleason) Date: Tue, 17 May 2022 12:27:57 -0500 Subject: DX/IAS software Message-ID: <7ce46daa-a033-b63e-19df-f6ae6b5ab90b@comcast.net> ? I have a tape from the late 70s that contains? DX/IAS, a package from DEC that allowed terminal emulation and file transfer to/from WPS on DECmates to IAS systems. Not too many IAS systems out there these days, but? the tape includes sources, so it should be easily adaptable to RSX systems, as well as giving some insight in general to the DX communications protocol. Anyone have a tape drive still running that could take a stab at reading this tape? It's not marked as to density, but it looks like one of those small 800 BPI tapes DEC used to deliver small packages on around that time. -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net From paulkoning at comcast.net Tue May 17 12:41:49 2022 From: paulkoning at comcast.net (Paul Koning) Date: Tue, 17 May 2022 13:41:49 -0400 Subject: DX/IAS software In-Reply-To: <7ce46daa-a033-b63e-19df-f6ae6b5ab90b@comcast.net> References: <7ce46daa-a033-b63e-19df-f6ae6b5ab90b@comcast.net> Message-ID: <478D9978-35EA-4C62-BFB9-8BB1C374623A@comcast.net> > On May 17, 2022, at 1:27 PM, Lee Gleason via cctalk wrote: > > I have a tape from the late 70s that contains DX/IAS, a package from DEC that allowed terminal emulation and file transfer to/from WPS on DECmates to IAS systems. Not too many IAS systems out there these days, but the tape includes sources, so it should be easily adaptable to RSX systems, ... I think there are IAS kits on Bitsavers. Porting to RSX: most straightforward would be to RSX-11/D since that's basically what IAS is. To /M or /M-plus may not be a whole lot harder, I don't have experience with that. paul From lee.gleason at comcast.net Tue May 17 16:31:55 2022 From: lee.gleason at comcast.net (Lee Gleason) Date: Tue, 17 May 2022 16:31:55 -0500 Subject: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? In-Reply-To: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> References: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> Message-ID: On 4/15/2022 2:48 PM, Lee Gleason wrote: > ? I've been tinkering with a PDT-11/150 lately. It's a little > inconvenient to work on, since it doesn't have a simple way to > transfer files back and forth (KRTMIN doesn't work when transferring > files to the box, just from the box, for some reason I haven't been > able to puzzle out, and pasting text into a KED screen or a PIP > command usually overflows my terminal emulator). > > ? It occurred to me that the first application terminal line on the > 150 is at 176500,300, the same as the default for a TU58's DL11. It's > a very DL11 like interface, register wise. I'm wondering, if I could > hook up a TU58 emulator and use it to move data back and forth to the > 150. > > ? Has anyone had occasion to try this? Any advice on how to get it to > go would? be appreciated, since I know very little about RT11. > > -- > Lee K. Gleason N5ZMR > Control-G Consultants > lee.gleason at comcast.net ? OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to? store lots of RT11 software or data? (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. See https://rsx11.blogspot.com/2022/05/pdt-11150-and-tu58.html for the long boring story about? figuring this out. == Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net From curiousmarc3 at gmail.com Tue May 17 22:26:27 2022 From: curiousmarc3 at gmail.com (Curious Marc) Date: Tue, 17 May 2022 20:26:27 -0700 Subject: Unsubscribed from the list due to too many bounces Message-ID: <6C958EA2-D6CF-4245-9392-F9015702E451@gmail.com> I have been auto-rejected from the list again, due to too many bounces, whatever this means. But I swear I have been a good boy and did not bounce too much! This is a plain vanilla gmail account by the way. Does anyone have any idea why this keeps happening? Anything I can do about it? Marc From tdk.knight at gmail.com Tue May 17 22:35:28 2022 From: tdk.knight at gmail.com (Adrian Stoness) Date: Tue, 17 May 2022 22:35:28 -0500 Subject: Unsubscribed from the list due to too many bounces In-Reply-To: <6C958EA2-D6CF-4245-9392-F9015702E451@gmail.com> References: <6C958EA2-D6CF-4245-9392-F9015702E451@gmail.com> Message-ID: its an issue with gmail according to jaywest dont think u can do anything about it its in his ballpark theres a thread discussing the issue so ur not alone thread "Cctalk subscription disabled" On Tue, May 17, 2022 at 10:26 PM Curious Marc via cctalk < cctalk at classiccmp.org> wrote: > I have been auto-rejected from the list again, due to too many bounces, > whatever this means. But I swear I have been a good boy and did not bounce > too much! This is a plain vanilla gmail account by the way. Does anyone > have any idea why this keeps happening? Anything I can do about it? > Marc From curiousmarc3 at gmail.com Tue May 17 22:38:12 2022 From: curiousmarc3 at gmail.com (Curious Marc) Date: Tue, 17 May 2022 20:38:12 -0700 Subject: Unsubscribed from the list due to too many bounces In-Reply-To: References: Message-ID: Thanks Adrian I feel better already :-) Marc > On May 17, 2022, at 8:35 PM, Adrian Stoness wrote: > > ? > its an issue with gmail according to jaywest dont think u can do anything about it > its in his ballpark > theres a thread discussing the issue so ur not alone > thread "Cctalk subscription disabled" > > > > > >> On Tue, May 17, 2022 at 10:26 PM Curious Marc via cctalk wrote: >> I have been auto-rejected from the list again, due to too many bounces, whatever this means. But I swear I have been a good boy and did not bounce too much! This is a plain vanilla gmail account by the way. Does anyone have any idea why this keeps happening? Anything I can do about it? >> Marc From cz at alembic.crystel.com Wed May 18 03:47:07 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Wed, 18 May 2022 10:47:07 +0200 Subject: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? In-Reply-To: References: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> Message-ID: <00FA8F2D-0481-4EE6-81CA-7E6E78911711@alembic.crystel.com> Very nice to know! I am repairing my tu58 bit by bit and will try it out on my 11/150. Good to know about the serial limit, I'll jumper for 2400 baud to test. Question. The only tape I have for testing is an xxdp. Are they in rt11 format that I can test with a simple directory command? Chris On May 17, 2022 11:31:55 PM GMT+02:00, Lee Gleason via cctalk wrote: >On 4/15/2022 2:48 PM, Lee Gleason wrote: >> ? I've been tinkering with a PDT-11/150 lately. It's a little inconvenient to work on, since it doesn't have a simple way to transfer files back and forth (KRTMIN doesn't work when transferring files to the box, just from the box, for some reason I haven't been able to puzzle out, and pasting text into a KED screen or a PIP command usually overflows my terminal emulator). >> >> ? It occurred to me that the first application terminal line on the 150 is at 176500,300, the same as the default for a TU58's DL11. It's a very DL11 like interface, register wise. I'm wondering, if I could hook up a TU58 emulator and use it to move data back and forth to the 150. >> >> ? Has anyone had occasion to try this? Any advice on how to get it to go would? be appreciated, since I know very little about RT11. >> >> -- >> Lee K. Gleason N5ZMR >> Control-G Consultants >> lee.gleason at comcast.net > >? OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to? store lots of RT11 software or data? (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. See https://rsx11.blogspot.com/2022/05/pdt-11150-and-tu58.html for the long boring story about? figuring this out. > >== >Lee K. Gleason N5ZMR >Control-G Consultants >lee.gleason at comcast.net -- Sent from my Android device with K-9 Mail. Please excuse my brevity. From lee.gleason at comcast.net Wed May 18 10:13:53 2022 From: lee.gleason at comcast.net (Lee Gleason) Date: Wed, 18 May 2022 10:13:53 -0500 Subject: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? In-Reply-To: <00FA8F2D-0481-4EE6-81CA-7E6E78911711@alembic.crystel.com> References: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> <00FA8F2D-0481-4EE6-81CA-7E6E78911711@alembic.crystel.com> Message-ID: ? Lessee...I know more about life on Mars than I do RT11, but I know from trying it myself, while building some XXDP volumes,? that a simple DIR command can't read an XXDP volume. Maybe there's an equivalent of FLX (RSX) or Exchange (VMS) on RT11? Either way, you can test your ability to read an XXDP TU58 on the PDT by doing a DUMP/TERMINAL DD0: - if it reads, it will dump the blocks out to your screen. It will be interesting to see if a real TU58 works as well on a PDT? as an emulator does. -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net On 5/18/2022 3:47 AM, Chris Zach wrote: > Very nice to know! I am repairing my tu58 bit by bit and will try it > out on my 11/150. Good to know about the serial limit, I'll jumper for > 2400 baud to test. > > Question. The only tape I have for testing is an xxdp. Are they in > rt11 format that I can test with a simple directory command? > > Chris > > On May 17, 2022 11:31:55 PM GMT+02:00, Lee Gleason via cctalk > wrote: > > On 4/15/2022 2:48 PM, Lee Gleason wrote: > > ? I've been tinkering with a PDT-11/150 lately. It's a little > inconvenient to work on, since it doesn't have a simple way to > transfer files back and forth (KRTMIN doesn't work when > transferring files to the box, just from the box, for some > reason I haven't been able to puzzle out, and pasting text > into a KED screen or a PIP command usually overflows my > terminal emulator). ? It occurred to me that the first > application terminal line on the 150 is at 176500,300, the > same as the default for a TU58's DL11. It's a very DL11 like > interface, register wise. I'm wondering, if I could hook up a > TU58 emulator and use it to move data back and forth to the > 150. ? Has anyone had occasion to try this? Any advice on how > to get it to go would? be appreciated, since I know very > little about RT11. > -- Lee K. Gleason N5ZMR Control-G Consultants > lee.gleason at comcast.net > > > ? OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to? store lots of RT11 software or data? (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. Seehttps://rsx11.blogspot.com/2022/05/pdt-11150-and-tu58.html for the long boring story about? figuring this out. > > == > Lee K. Gleason N5ZMR > Control-G Consultants > lee.gleason at comcast.net > > -- Sent from my Android device with K-9 Mail. Please excuse my brevity. From mjd.bishop at emeritus-solutions.com Wed May 18 14:47:18 2022 From: mjd.bishop at emeritus-solutions.com (Martin Bishop) Date: Wed, 18 May 2022 19:47:18 +0000 Subject: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? In-Reply-To: References: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> <00FA8F2D-0481-4EE6-81CA-7E6E78911711@alembic.crystel.com> Message-ID: XXDP is based on DOS-11 file structures. Some documentary sources FoMT. TU58 examples of XXDP binaries, and much more, can be found at https://www.ak6dn.com/PDP-11/TU58/ the .txt files contain file structure and directory listings. http://bitsavers.trailing-edge.com/pdf/dec/dectape/tu58/EK-0TU58-UG-001_TU58_DECtape_II_Users_Guide_Oct78.pdf is a fair description of TU58 technology https://github.com/rust11/xxdp/tree/main XXDP RevEng and restored sources http://www.bitsavers.org/pdf/dec/pdp11/dos-batch/ I believe documents the DOS-11 file system underlying XXDP; e.g. it explains how dates are encoded. Martin -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Lee Gleason via cctalk Sent: 18 May 2022 16:14 To: Chris Zach ; cctalk at classiccmp.org Subject: Re: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? ? Lessee...I know more about life on Mars than I do RT11, but I know from trying it myself, while building some XXDP volumes,? that a simple DIR command can't read an XXDP volume. Maybe there's an equivalent of FLX (RSX) or Exchange (VMS) on RT11? Either way, you can test your ability to read an XXDP TU58 on the PDT by doing a DUMP/TERMINAL DD0: - if it reads, it will dump the blocks out to your screen. It will be interesting to see if a real TU58 works as well on a PDT? as an emulator does. -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net On 5/18/2022 3:47 AM, Chris Zach wrote: > Very nice to know! I am repairing my tu58 bit by bit and will try it > out on my 11/150. Good to know about the serial limit, I'll jumper for > 2400 baud to test. > > Question. The only tape I have for testing is an xxdp. Are they in > rt11 format that I can test with a simple directory command? > > Chris > > On May 17, 2022 11:31:55 PM GMT+02:00, Lee Gleason via cctalk > wrote: > > On 4/15/2022 2:48 PM, Lee Gleason wrote: > > ? I've been tinkering with a PDT-11/150 lately. It's a little > inconvenient to work on, since it doesn't have a simple way to > transfer files back and forth (KRTMIN doesn't work when > transferring files to the box, just from the box, for some > reason I haven't been able to puzzle out, and pasting text > into a KED screen or a PIP command usually overflows my > terminal emulator). ? It occurred to me that the first > application terminal line on the 150 is at 176500,300, the > same as the default for a TU58's DL11. It's a very DL11 like > interface, register wise. I'm wondering, if I could hook up a > TU58 emulator and use it to move data back and forth to the > 150. ? Has anyone had occasion to try this? Any advice on how > to get it to go would? be appreciated, since I know very > little about RT11. > -- Lee K. Gleason N5ZMR Control-G Consultants > lee.gleason at comcast.net > > > ? OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to? store lots of RT11 software or data? (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. Seehttps://rsx11.blogspot.com/2022/05/pdt-11150-and-tu58.html for the long boring story about? figuring this out. > > == > Lee K. Gleason N5ZMR > Control-G Consultants > lee.gleason at comcast.net > > -- Sent from my Android device with K-9 Mail. Please excuse my brevity. From cruff at ruffspot.net Wed May 18 12:45:34 2022 From: cruff at ruffspot.net (Craig Ruff) Date: Wed, 18 May 2022 11:45:34 -0600 Subject: Alphastation 200 login (Wayne S) In-Reply-To: References: Message-ID: > On May 18, 2022, at 11:00, cctech-request at classiccmp.org wrote: > > Got my Alphastation to boot but i can?t logon because i don?t the administrator password? Any ideas on how to get past that? It depends on the OS installed. For Unix-style OS you need to figure out the single user boot mode, which may mean passing "-s" or "single" in the boot arguments from the ROM. For VMS, if I recall correctly, you set the boot R5 register to 1. Then obviously the reset of the administrator user password is also OS dependent. From billdegnan at gmail.com Wed May 18 13:04:56 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 18 May 2022 14:04:56 -0400 Subject: Alphastation 200 login (Wayne S) In-Reply-To: References: Message-ID: clues if your Alpha uses VMS https://www.vintagecomputer.net/browse_thread.cfm?id=610 Clues if DEC UNIX https://www.vintagecomputer.net/browse_thread.cfm?id=679 b On Wed, May 18, 2022 at 1:45 PM Craig Ruff via cctech wrote: > > > > On May 18, 2022, at 11:00, cctech-request at classiccmp.org wrote: > > > > Got my Alphastation to boot but i can?t logon because i don?t the administrator password? Any ideas on how to get past that? > > It depends on the OS installed. For Unix-style OS you need to figure out the single user boot mode, which may mean passing "-s" or "single" in the boot arguments from the ROM. For VMS, if I recall correctly, you set the boot R5 register to 1. Then obviously the reset of the administrator user password is also OS dependent. From glen.slick at gmail.com Wed May 18 13:10:04 2022 From: glen.slick at gmail.com (Glen Slick) Date: Wed, 18 May 2022 11:10:04 -0700 Subject: Alphastation 200 login (Wayne S) In-Reply-To: References: Message-ID: On Wed, May 18, 2022 at 10:45 AM Craig Ruff via cctech wrote: > > > On May 18, 2022, at 11:00, cctech-request at classiccmp.org wrote: > > > > Got my Alphastation to boot but i can?t logon because i don?t the administrator password? Any ideas on how to get past that? > > For VMS, if I recall correctly, you set the boot R5 register to 1. Then obviously the reset of the administrator user password is also OS dependent. Here's one example description of how to do that with OpenVMS. https://web.archive.org/web/20151122033453/http://labs.hoffmanlabs.com/node/204 From glen.slick at gmail.com Wed May 18 13:45:35 2022 From: glen.slick at gmail.com (Glen Slick) Date: Wed, 18 May 2022 11:45:35 -0700 Subject: Alphastation 200 login (Wayne S) In-Reply-To: References: Message-ID: On Wed, May 18, 2022 at 11:25 AM Wayne S via cctech wrote: > > I should have specifically said it?s Windows Nt. Issue is that it?s an Alpha so can?t use the usual software to change or remove the password unless there?s an Alpha version. Best suggestion so far is to use a version of Unix that runs on Alpha and rename the SAM file. Or maybe try attaching the boot drive to an x86 system and try using the usual Windows NT password reset tools? (e.g. chntpw Live CD) I have no idea if all of the file systems and data file formats are identical enough between x86 and Alpha versions of Windows NT. Would probably be a good idea to make a backup image of the boot drive before using any tools to modify its contents. From billdegnan at gmail.com Wed May 18 15:50:02 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Wed, 18 May 2022 16:50:02 -0400 Subject: Alphastation 200 login (Wayne S) In-Reply-To: References: Message-ID: I have the nt install cd for alpha someplace I am sure it's available as an iso online too. You can set.the pw when you build, of that's the route you're taking. On Wed, May 18, 2022, 4:34 PM Glen Slick via cctalk wrote: > On Wed, May 18, 2022 at 11:25 AM Wayne S via cctech > wrote: > > > > I should have specifically said it?s Windows Nt. Issue is that it?s an > Alpha so can?t use the usual software to change or remove the password > unless there?s an Alpha version. Best suggestion so far is to use a version > of Unix that runs on Alpha and rename the SAM file. > > Or maybe try attaching the boot drive to an x86 system and try using > the usual Windows NT password reset tools? (e.g. chntpw Live CD) I > have no idea if all of the file systems and data file formats are > identical enough between x86 and Alpha versions of Windows NT. > > Would probably be a good idea to make a backup image of the boot drive > before using any tools to modify its contents. > From cz at alembic.crystel.com Thu May 19 05:16:07 2022 From: cz at alembic.crystel.com (Chris Zach) Date: Thu, 19 May 2022 12:16:07 +0200 Subject: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? In-Reply-To: References: <5d193fd7-e9f3-ef07-f10f-bd84dd080dd5@comcast.net> <00FA8F2D-0481-4EE6-81CA-7E6E78911711@alembic.crystel.com> Message-ID: <1EDCE52D-9FCF-4CAF-9A5C-8781D01DCA62@alembic.crystel.com> Ok. Well if all the tu58 tapes have been imaged then this should not be a problem. I can just overwrite it as needed. I think I have a few more somewhere around here from 30 years ago..... On May 18, 2022 9:47:18 PM GMT+02:00, Martin Bishop via cctalk wrote: >XXDP is based on DOS-11 file structures. > >Some documentary sources FoMT. > >TU58 examples of XXDP binaries, and much more, can be found at >https://www.ak6dn.com/PDP-11/TU58/ the .txt files contain file structure and directory listings. > >http://bitsavers.trailing-edge.com/pdf/dec/dectape/tu58/EK-0TU58-UG-001_TU58_DECtape_II_Users_Guide_Oct78.pdf is a fair description of TU58 technology > >https://github.com/rust11/xxdp/tree/main XXDP RevEng and restored sources > >http://www.bitsavers.org/pdf/dec/pdp11/dos-batch/ I believe documents the DOS-11 file system underlying XXDP; e.g. it explains how dates are encoded. > >Martin > >-----Original Message----- >From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Lee Gleason via cctalk >Sent: 18 May 2022 16:14 >To: Chris Zach ; cctalk at classiccmp.org >Subject: Re: anyone ever connect a TU58 drive to a PDT-11/150 terminal port? > > ? Lessee...I know more about life on Mars than I do RT11, but I know from trying it myself, while building some XXDP volumes,? that a simple DIR command can't read an XXDP volume. Maybe there's an equivalent of FLX (RSX) or Exchange (VMS) on RT11? Either way, you can test your ability to read an XXDP TU58 on the PDT by doing a DUMP/TERMINAL DD0: - if it reads, it will dump the blocks out to your screen. It will be interesting to see if a real TU58 works as well on a PDT? as an emulator does. >-- >Lee K. Gleason N5ZMR >Control-G Consultants >lee.gleason at comcast.net > >On 5/18/2022 3:47 AM, Chris Zach wrote: >> Very nice to know! I am repairing my tu58 bit by bit and will try it >> out on my 11/150. Good to know about the serial limit, I'll jumper for >> 2400 baud to test. >> >> Question. The only tape I have for testing is an xxdp. Are they in >> rt11 format that I can test with a simple directory command? >> >> Chris >> >> On May 17, 2022 11:31:55 PM GMT+02:00, Lee Gleason via cctalk >> wrote: >> >> On 4/15/2022 2:48 PM, Lee Gleason wrote: >> >> ? I've been tinkering with a PDT-11/150 lately. It's a little >> inconvenient to work on, since it doesn't have a simple way to >> transfer files back and forth (KRTMIN doesn't work when >> transferring files to the box, just from the box, for some >> reason I haven't been able to puzzle out, and pasting text >> into a KED screen or a PIP command usually overflows my >> terminal emulator). ? It occurred to me that the first >> application terminal line on the 150 is at 176500,300, the >> same as the default for a TU58's DL11. It's a very DL11 like >> interface, register wise. I'm wondering, if I could hook up a >> TU58 emulator and use it to move data back and forth to the >> 150. ? Has anyone had occasion to try this? Any advice on how >> to get it to go would? be appreciated, since I know very >> little about RT11. >> -- Lee K. Gleason N5ZMR Control-G Consultants >> lee.gleason at comcast.net >> >> >> ? OK, replying to my own post here, on the off chance that there are any other PDT-11 hobbyists out there. I gave this a try and it works pretty well. The DD driver on the PDT-11/150 will talk to a TU58 emulator on Terminal 1 just fine (presumably, it would talk to a real TU58 as well). It only works at 2400 baud, but, it's still pretty useful for moving software on and off the box. With the "big" TU58 patch to the DD driver, it's also possible to? store lots of RT11 software or data? (65000 or so blocks worth) on a virtual TU58 and load from there, rather than switching floppies. Seehttps://rsx11.blogspot.com/2022/05/pdt-11150-and-tu58.html for the long boring story about? figuring this out. >> >> == >> Lee K. Gleason N5ZMR >> Control-G Consultants >> lee.gleason at comcast.net >> >> -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -- Sent from my Android device with K-9 Mail. Please excuse my brevity. From pbirkel at gmail.com Sun May 22 01:26:06 2022 From: pbirkel at gmail.com (pbirkel at gmail.com) Date: Sun, 22 May 2022 02:26:06 -0400 Subject: Diablo Series 30 removable disk drives & sector sensor Message-ID: <01c901d86da4$d201d830$76058890$@gmail.com> I've been researching uses of the IBM 2315 disk pack design in various systems. There appear to be two styles of sensors used for sector identification in IBM 2315 disk pack designs. The IBM 2310 disk drive used an optical sensor and notched-ring integrated into the spindle so that a U-shaped assembly of light+sensor is appropriately positioned when the pack is mounted (see: https://www.manualslib.com/products/Ibm-2310-10271354.html ). DEC also used this style in their RK05 drives (see: EK-RK5JF-MM-001_RKO5_RK05J_RK05F_Disk_Drive_Maintenance_Manual_Nov76.pdf, Figure 1-3 and Section 4.2.6 on page 4-16 (56-of-135) "an optical device that contains a light emitting diode and a photosensor". The other style utilizes a magnetic sensor and the hub (perimeter of the flat surface to which the pack is affixed when mounted) itself is notched. A flat sensor including a magnet is suitably positioned with respect to that face when the pack is mounted. HP used this style in their HP7906 drive, which combined a removable disk with a fixed disk (the fixed disk actually provided the sector-timing information for the removeable disk pack; the removeable disk itself only had a single index notch on the hub). I've become confused about the one used with Diablo Series 30 drives, typically employed by OEMs (e.g., Data General). I assume that it was one-or-the-other, but perhaps either might be used based on the requirement of a particular OEM? In D3140-171_Maintanance_Manual_For_Series-30_Disk_Drive_Jan72.pdf, on page 7-17 (92-of-103) Figure 7-9 SECTOR TRANSDUCER ASSEMBLY clearly illustrates the mechanism of a magnetic transducer, although nowhere can I find Series 30 technical documentation that specifically discusses the nature of its sector transducer. All schematics that I have checked do not seem to include any provisions for powering a light source, which is consistent with the use of a magnetic transducer. However https://www.righto.com/2018/03/a-1970s-disk-drive-that-wouldnt-seek.html from Ken Shirriff shows a Diablo drive where Ken clearly (https://lh3.googleusercontent.com/-_meZQXUR5NQ/Wr-34VTNwUI/AAAAAAABQe4/fhC1 75xg0Mcm6eeytILHMyUGZ1TFAUzkwCHMYBhgL/w9999/disk-opened.jpg) illustrates a disk pack that is hard-sectored based on slots-in-ring which AFAIK implies an optical sensor. He references 81503-02_Series_30_Disk_Drive_Maintenance_Nov75.pdf which is non-specific regarding the sector transducer, but on page 5-6 (41-of-63) it refers to there being "two interconnecting wires at the transducer" and Figure 5-7 SECTOR TRANSDUCER ADJUSTMENT appears to me to be consistent with the earlier maintenance manual Figure 7-9 SECTOR TRANSDUCER ASSEMBLY - a magnetic transducer. So is the opened disk pack not actually one for a Diablo Series 30 drive? Or did the Diablo Series 30 include an OEM-specific (?) variant that used an optical sensor? Or perhaps there's something else going on here with the various IBM 2315 disk pack designs regarding sector sensing that I fail to understand? ----- paul From dennis.grevenstein at gmail.com Sun May 22 10:17:16 2022 From: dennis.grevenstein at gmail.com (Dennis Grevenstein) Date: Sun, 22 May 2022 17:17:16 +0200 Subject: HP-UX patch PHSS_44401 Message-ID: Hi, Maybe asking here is worth a try: I?ve got an HP Itanium machine running HP-UX 11.23. There seems to be a bug in ld, which prevents building newer gcc versions: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64919 That?s my current status: # what /usr/bin/ld /usr/bin/ld: ld_msgs.cat: $Revision: 1.85 $ 92453-07 linker ld HP Itanium(R) B.12.54 IPF/IPF REL Tue, Dec 8, 2009 01:08:02 PM PST HP aC++ for Integrity Servers B3910B A.06.20 [May 13 2008] C++ Standard Library (RogueWave Version 2.02.01) HP aC++ for Integrity Servers B3910B A.06.20 [May 13 2008] Language Support Library # uname -a HP-UX itanium B.11.23 U ia64 HP-UX The problem was supposedly fixed in 2015 with patch PHSS_44401. Does anybody here have this patch and could help me out? thanks, Dennis From ajkatx at gmail.com Tue May 24 13:12:08 2022 From: ajkatx at gmail.com (Andrew Kay) Date: Tue, 24 May 2022 13:12:08 -0500 Subject: How did VMSHARE user interface work? Message-ID: I have been browsing through some of the VMSHARE archives at http://vm.marist.edu/~vmshare/, and I'm curious to know how a user would have interacted with this system. I tried finding a "help" file or similar within the archive itself but couldn't find anything obvious. I think I saw a couple of names there that I'd seen here so figure this is as good a place as any to ask if anyone can enlighten me. >From what I can tell users would connect to a VM host, would they each have their own account or was it some shared account? Once you were connected, was there some special interface to the system - or did you just use CMS tools (like XEDIT)? It looks like discussions were managed by appending a message to a file (a file per topic), was this something that would be done "manually" or was there some sort of a script that would take your message and append it to the file? How would you know there were new messages in a particular file you were interested in? Would you have to open each file (or, perhaps look at its modified date) or was there a different interface used to actually read messages? Thanks in advance :) Andrew From dave.g4ugm at gmail.com Wed May 25 04:40:05 2022 From: dave.g4ugm at gmail.com (dave.g4ugm at gmail.com) Date: Wed, 25 May 2022 10:40:05 +0100 Subject: How did VMSHARE user interface work? In-Reply-To: References: Message-ID: <095601d8701b$6afaaa30$40effe90$@gmail.com> > -----Original Message----- > From: cctalk On Behalf Of Andrew Kay via > cctalk > Sent: 24 May 2022 19:12 > To: General Discussion: On-Topic and Off-Topic Posts > > Subject: How did VMSHARE user interface work? > > I have been browsing through some of the VMSHARE archives at > http://vm.marist.edu/~vmshare/, and I'm curious to know how a user would > have interacted with this system. I tried finding a "help" file or similar within > the archive itself but couldn't find anything obvious. I think I saw a couple of > names there that I'd seen here so figure this is as good a place as any to ask if > anyone can enlighten me. There is still a VM list and some one on their might remember... Do you know I can't remember the details either! There were multiple ways to interact. I think at the start we didn't have terminal connectivity and got daily digests. > > From what I can tell users would connect to a VM host, would they each have > their own account or was it some shared account? > > Once you were connected, was there some special interface to the system - > or did you just use CMS tools (like XEDIT)? It was a specialist padded cell environment. The user names were local to VM Share. If you look in http://vm.marist.edu/~vmshare/browse.cgi?fn=CONTACT&ft=MEMO you will see that it was offered by Adesse as "CONTACT" but I can't find anything docs for that either.. > > It looks like discussions were managed by appending a message to a file (a > file per topic), was this something that would be done "manually" or was > there some sort of a script that would take your message and append it to > the file? > It was all handled in the package > How would you know there were new messages in a particular file you were > interested in? Would you have to open each file (or, perhaps look at its > modified date) or was there a different interface used to actually read > messages? > There were commands to list new updates since you last logged in. > Thanks in advance :) > > > Andrew Dave From ajkatx at gmail.com Wed May 25 07:59:00 2022 From: ajkatx at gmail.com (Andrew Kay) Date: Wed, 25 May 2022 07:59:00 -0500 Subject: How did VMSHARE user interface work? In-Reply-To: <095601d8701b$6afaaa30$40effe90$@gmail.com> References: <095601d8701b$6afaaa30$40effe90$@gmail.com> Message-ID: Thank you Dave, your name was one that I had recognized in the archives! Understanding that it was more of a separate program and interface helps me get a better picture, the CONTACT MEMO you mentioned includes a lot of useful hints as to the interface. Andrew On Wed, May 25, 2022 at 4:40 AM wrote: > > > -----Original Message----- > > From: cctalk On Behalf Of Andrew Kay via > > cctalk > > Sent: 24 May 2022 19:12 > > To: General Discussion: On-Topic and Off-Topic Posts > > > > Subject: How did VMSHARE user interface work? > > > > I have been browsing through some of the VMSHARE archives at > > http://vm.marist.edu/~vmshare/, and I'm curious to know how a user would > > have interacted with this system. I tried finding a "help" file or similar within > > the archive itself but couldn't find anything obvious. I think I saw a couple of > > names there that I'd seen here so figure this is as good a place as any to ask if > > anyone can enlighten me. > > There is still a VM list and some one on their might remember... > Do you know I can't remember the details either! > There were multiple ways to interact. I think at the start we didn't have terminal connectivity and got daily digests. > > > > > From what I can tell users would connect to a VM host, would they each have > > their own account or was it some shared account? > > > > Once you were connected, was there some special interface to the system - > > or did you just use CMS tools (like XEDIT)? > > It was a specialist padded cell environment. The user names were local to VM Share. > If you look in > > http://vm.marist.edu/~vmshare/browse.cgi?fn=CONTACT&ft=MEMO > > you will see that it was offered by Adesse as "CONTACT" but I can't find anything docs for that either.. > > > > > It looks like discussions were managed by appending a message to a file (a > > file per topic), was this something that would be done "manually" or was > > there some sort of a script that would take your message and append it to > > the file? > > > > It was all handled in the package > > > How would you know there were new messages in a particular file you were > > interested in? Would you have to open each file (or, perhaps look at its > > modified date) or was there a different interface used to actually read > > messages? > > > > There were commands to list new updates since you last logged in. > > > Thanks in advance :) > > > > > > Andrew > > Dave > From bill.gunshannon at hotmail.com Wed May 25 08:07:05 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Wed, 25 May 2022 09:07:05 -0400 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: Another question for the masters here. I just tried to revive my Model III. More than half the keys don't work anymore. What is the conventional wisdom on cleaning these old TRS-80 keyboards? Is compressed air usually enough? Can I spray the switches with something like DeOxit safely? I expect when I go to revive my Model I's they are likely to be in the same state. bill From ard.p850ug1 at gmail.com Wed May 25 08:20:38 2022 From: ard.p850ug1 at gmail.com (Tony Duell) Date: Wed, 25 May 2022 14:20:38 +0100 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Wed, May 25, 2022 at 2:07 PM Bill Gunshannon via cctalk wrote: > > > Another question for the masters here. > > I just tried to revive my Model III. More than half the > keys don't work anymore. What is the conventional wisdom > on cleaning these old TRS-80 keyboards? Is compressed air > usually enough? Can I spray the switches with something > like DeOxit safely? I expect when I go to revive my > Model I's they are likely to be in the same state. > I think there were several keyboards used, the one I know (I have versions in the Model 3 and Model 4) was made by ALPS Anyway the switches in that have little conductive rubber pads on the end of the key plunger, These are pressed against a pair of metal contacts at the bottom of the switch to complete the circuit. Of course the rubber wears. Cleaning,trying to re-surface the rubber, etc, makes only a temporary repair, but it's better than nothing. I started by pulling the keycaps off. Then I desolded all the switches from the PCB (it sounds a worse job than it is!). Took the PCB off, then unclipped the switches from the metal frame. The switches do come apart by unclippng the 2 halves of the housing. I cleaned the metal contacts with propan-2-ol, lightly rubbed the rubber on fine wet-n-dry paper and rubbed a soft pencil -- the softest I could get, a 6B I think -- on the face of the pad. Put the switch back together and measured the resistance when it was pressed. Not that the input circuit on the CPU board of these machines is quite high resistance, so a switch that has a resistance of, say 1k ohms will work fine. In the end I got it down to having 3 or 4 that were a bit dubious, needing harder-than-normal pressure or not working every time. Those I put in the numeric keypad area of the keyboard, I could easily live without that... Incdentally old Model1 machines have the metal contact keyboards, same contacts as the DEC VT52, VT100, the HP85, etc, the TI99/4A etc. Those are a lote more reliable. -tony > bill > > From cisin at xenosoft.com Wed May 25 10:33:02 2022 From: cisin at xenosoft.com (Fred Cisin) Date: Wed, 25 May 2022 08:33:02 -0700 (PDT) Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: On Wed, 25 May 2022, Bill Gunshannon via cctalk wrote: > Another question for the masters here. > I just tried to revive my Model III. More than half the > keys don't work anymore. What is the conventional wisdom > on cleaning these old TRS-80 keyboards? Is compressed air > usually enough? Can I spray the switches with something > like DeOxit safely? I expect when I go to revive my > Model I's they are likely to be in the same state. A really stupid suggestion: (cleaning the key mechanisms makes more sense): More than a quarter of a century ago, I revived several of my TRS-80's. None of the keys worked on one keyboard, and many of the keys didn't work on another. But, I noticed that repeatedly pressing an intermittent key made it work reliably, and repeatedly pressing a "dead" key got it working! I had a Rochester Dynatyper and a KGS-80, which were the two most common versions of a box of solenoids to place on top of a typewriter to convert it into a printer. Those came out when there were no cheap printers. There also existed a box, made by an outfit in Walnut Creek, to put UNDER a Selectric that pulled down on the keys, but I neever had one of those, and that was ONLY for Selectric, whereas the Rochester Dynatyper and the KGS-80 worked on ANYTHING with a normal keyboard, even a Merganthaler! I remember once at the West Coast Computer Faire, somebody showed a prototype of one that used fishing line and pulleys to work the carriage return of a MANUAL (non-electric) typewriter - every successful carriage return got a round of applause. I used the Dynatyper and the KGS-80 to "type" a few hundred pages. The TRS-80 keyboards came back to life! -- Grumpy Ol' Fred From mjd.bishop at emeritus-solutions.com Wed May 25 17:03:53 2022 From: mjd.bishop at emeritus-solutions.com (Martin Bishop) Date: Wed, 25 May 2022 22:03:53 +0000 Subject: The TRS-80 Journey Continues In-Reply-To: References: Message-ID: I had dysfunctional switches on a heating system timer. The trade advice since replacements were unobtanium was open them up and clean the contacts with switch cleaner. The contacts were two "gold" plated pads bridged by pressing down conductive plastic with a textured finish : same design as the keyboards. The cotton buds lifted a lot of black "tarnish" (probably airborne contaminants) from the contacts. Went from a few working, a few intermittent and some totally dead, to all 16 working all the time. Have to see if they last another 12 years before failing. I infer that cleaning off the contaminants is 95% of the solution. I doubt the solvent used is especially critical. Martin -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Fred Cisin via cctalk Sent: 25 May 2022 16:33 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: The TRS-80 Journey Continues On Wed, 25 May 2022, Bill Gunshannon via cctalk wrote: > Another question for the masters here. > I just tried to revive my Model III. More than half the keys don't > work anymore. What is the conventional wisdom on cleaning these old > TRS-80 keyboards? Is compressed air usually enough? Can I spray the > switches with something like DeOxit safely? I expect when I go to > revive my Model I's they are likely to be in the same state. A really stupid suggestion: (cleaning the key mechanisms makes more sense): More than a quarter of a century ago, I revived several of my TRS-80's. None of the keys worked on one keyboard, and many of the keys didn't work on another. But, I noticed that repeatedly pressing an intermittent key made it work reliably, and repeatedly pressing a "dead" key got it working! I had a Rochester Dynatyper and a KGS-80, which were the two most common versions of a box of solenoids to place on top of a typewriter to convert it into a printer. Those came out when there were no cheap printers. There also existed a box, made by an outfit in Walnut Creek, to put UNDER a Selectric that pulled down on the keys, but I neever had one of those, and that was ONLY for Selectric, whereas the Rochester Dynatyper and the KGS-80 worked on ANYTHING with a normal keyboard, even a Merganthaler! I remember once at the West Coast Computer Faire, somebody showed a prototype of one that used fishing line and pulleys to work the carriage return of a MANUAL (non-electric) typewriter - every successful carriage return got a round of applause. I used the Dynatyper and the KGS-80 to "type" a few hundred pages. The TRS-80 keyboards came back to life! -- Grumpy Ol' Fred From ryan at ryandelaplante.ca Sat May 28 16:55:50 2022 From: ryan at ryandelaplante.ca (Ryan de Laplante) Date: Sat, 28 May 2022 17:55:50 -0400 Subject: WTB: DEC VT52, TU56 Message-ID: <2BF588A9-BA53-41C8-96CE-0AB84C91C111@ryandelaplante.ca> I?m looking to buy a VT52 to go with my PDP 11/45. I know these are hard to find and won?t be cheap to buy or ship. I have a VT05 and VT100, just need the VT52 now. I have a working ASR/33 in nice working condition that I can trade if interested. Also looking to buy a TU56 tape drive and controller for the PDP 11/45. - obsol33t From sieler at allegrosupport.com Sun May 29 22:42:30 2022 From: sieler at allegrosupport.com (Stan Sieler) Date: Sun, 29 May 2022 20:42:30 -0700 Subject: Canon AI Note IN-3000 and IN-5000 question Message-ID: Hi, Does anyone know when the Canon AI Note IN-5000 was released? The nearly identical Canon AI Note IN-3000 came out in 1989, and I wonder (without proof) if it (3000) might have a been a slightly later, cost-reduced version of the 5000. Google searching came up empty for the IN-5000, and all hits I got for the IN-3000 were copies of an old ebay-like page offering one some years ago. It's a Newton/Magic like calculator (and more) that recognized handwritten equations (and more). thanks, Stan From bill.gunshannon at hotmail.com Mon May 30 17:06:44 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Mon, 30 May 2022 18:06:44 -0400 Subject: PL/M & CP/M Message-ID: Recently in my wanderings on the web I saw a comment(I don't remember where) that said at least one of the PLM-80 compilers floating around was built from a dis-assembly of another one. Does this ring a bell with anyone? Would anyone know where I might find these sources? I have the Fortran version running but I would like to look into something capable of running on an 8bit system. bill From cclist at sydex.com Mon May 30 17:20:09 2022 From: cclist at sydex.com (Chuck Guzis) Date: Mon, 30 May 2022 15:20:09 -0700 Subject: PL/M & CP/M In-Reply-To: References: Message-ID: Are you talking about this? https://web.archive.org/web/20131110002247/http://www.nj7p.info/Common/Toys/Software/OS/work/IntelTools.zip (Courtesy of Mark Ogden) --Chuck On 5/30/22 15:06, Bill Gunshannon via cctalk wrote: > > Recently in my wanderings on the web I saw a comment(I don't > remember where) that said at least one of the PLM-80 compilers > floating around was built from a dis-assembly of another one. > Does this ring a bell with anyone?? Would anyone know where I > might find these sources?? I have the Fortran version running > but I would like to look into something capable of running on > an 8bit system. > > bill -- --Chuck Sent from my digital computer From bill.gunshannon at hotmail.com Mon May 30 17:29:23 2022 From: bill.gunshannon at hotmail.com (Bill Gunshannon) Date: Mon, 30 May 2022 18:29:23 -0400 Subject: PL/M & CP/M In-Reply-To: References: Message-ID: On 5/30/22 18:20, Chuck Guzis via cctalk wrote: > Are you talking about this? > > https://web.archive.org/web/20131110002247/http://www.nj7p.info/Common/Toys/Software/OS/work/IntelTools.zip > > (Courtesy of Mark Ogden) > Not what I thought I was looking for but may turn out very useful anyway. I might be able to build a system and then dis-assemble it to Z80 mnemonics. In any event, it will make fun reading. Thank you. bill From billdegnan at gmail.com Tue May 31 19:32:42 2022 From: billdegnan at gmail.com (Bill Degnan) Date: Tue, 31 May 2022 20:32:42 -0400 Subject: IBM PC Connecting to DECNET Message-ID: Here is a link to a set of screen shot of the autoexec.bat and config.sys for an IBM PC I came across today and the boot screen when these are attempted without the networking hardware attached.. https://www.vintagecomputer.net/IBM/5150/5150_DEC/ Specific to IBMPC to DECNET networking...anyone worked in this environment? Not me. I don't have the D drive that fails or the network, but I am curious what I would need to make this work. Maybe I can put something together. Anyone using a Digital Ethernet Personal Computer Bus Adapter today? The A drive had a jumper between 4-pin connectors 10 and 13 but it was not functional and I replaced the drive entirely. Not sure if I needed a 720K drive attached externally or something in order for the 5 1/4" drive jumpered this way to work. I have a pic of this there too. Weird. Thanks in advance. BIll From drb at msu.edu Tue May 31 23:48:58 2022 From: drb at msu.edu (Dennis Boone) Date: Wed, 01 Jun 2022 00:48:58 -0400 Subject: IBM PC Connecting to DECNET In-Reply-To: (Your message of Tue, 31 May 2022 20:32:42 -0400.) References: Message-ID: <20220601044858.96C7A40F235@yagi.h-net.msu.edu> > Specific to IBMPC to DECNET networking...anyone worked in this > environment? Not me. I don't have the D drive that fails or the > network, but I am curious what I would need to make this work. Maybe > I can put something together. Anyone using a Digital Ethernet > Personal Computer Bus Adapter today? If the stack that's installed is DECnet/DOS, then there are a few docs on bitsavers. I'd guess that the command "C:\CJR" leads to the stuff that loads the network stack and tries to set up the connections. The stack may have drivers for other ethernet card types. If it is some form of DECnet then it might be able to talk to, say, a DECnet Phase IV stack on an emulated vax, making it fairly easy to set up a test. If it's not DECnet/DOS, sniffing the files in the C:\DEC file tree might be informative. De From glen.slick at gmail.com Tue May 31 23:49:37 2022 From: glen.slick at gmail.com (Glen Slick) Date: Tue, 31 May 2022 21:49:37 -0700 Subject: IBM PC Connecting to DECNET In-Reply-To: References: Message-ID: On Tue, May 31, 2022 at 8:56 PM Bill Degnan via cctalk wrote: > > Specific to IBMPC to DECNET networking...anyone worked in this > environment? Not me. I don't have the D drive that fails or the > network, but I am curious what I would need to make this work. Maybe > I can put something together. Anyone using a Digital Ethernet > Personal Computer Bus Adapter today? > No one ever called it a "Digital Ethernet Personal Computer Bus Adapter", just a DEPCA. I never previously knew that there was any meaning behind the DEPCA name. I have a DEPCA in a 486 box that I got set up a while ago with some version of DECnet DOS, or Pathworks, from here, I forget which version without setting it up to take a look: http://www.bitsavers.org/bits/DEC/decnet/ Over 30 years ago I worked on PC DECwindows for DOS for a couple of years. There were Rational 286 and PharLap 386 DOS Extender versions. The DECnet DOS development was in a different group in a different building. The PC DECwindows for DOS server used DECnet DOS as a network transport.