The PDP-7, introduced in 1965, was DEC's third 18-bit computer system. Both faster and less expensive than the PDP-1, the PDP-7 maintained upward compatibility from the PDP-4 but introduced many new options, including extended memory, extended arithmetic capability, and a crude form of memory protection. The PDP-7 featured DEC's first mass storage operating system (DECsys, based on DECtapes). It was also the development system for the first versions of UNIX.
Photographs (courtesy of Digital Equipment Corporation):
| Option | Description | Capacity |
| CPU and memory | PDP-7 | 4KW - 32KW |
| CPU options | Type 177 EAE, extended arithmetic element | |
| Type 148 memory extension control | ||
| Console | Type 649 KSR-33 Teletype | |
| Paper tape | Type 444 paper tape reader | |
| Type 75 paper tape punch | ||
| Real time clock | integral | |
| Line printer | Type 647B line printer (sixbit ASCII) | |
| DECtape | Type 550/555 DECtape | 148KW |
| Drum | Type 24 serial drum | 131KW |
Updated 21-Apr-2003 by Bob Supnik (bob AT supnik DOT org - anti-spam encoded)