PDP-7
| PDP-7 | |
 A PDP-7 in Oslo, Norway | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Year Introduced: | 1965 |
| Form Factor: | minicomputer |
| Word Size: | 18 bits |
| Logic Type: | PNP Transistor FLIP CHIPs |
| Memory Speed: | 1.75 μsec |
| Physical Address Size: | 15 bits (32K words) |
| Virtual Address Size: | 13 bits (direct), 15 bits (extended) |
| Operating System: | DECSYS-7 |
| Predecessor(s): | PDP-4 |
| Successor(s): | PDP-9 |
| Price: | US$72K |
The PDP-7 is a minicomputer produced by DEC, introduced in 1965; with a low cost, it was cheap but powerful. There were two models, the second being the -7/A, but the difference is not yet clarified. Approximately 120 are thought to have been built.
The PDP-7 was the third of Digital's 18-bit machines, with essentially the same instruction set and architecture as the predecessor PDP-4 and successor PDP-9. It was the first wire-wrapped PDP. It was the first to use their Flip-Chip® technology, but also included the older System Modules.
In 1969, Ken Thompson wrote the first UNIX system in assembly language on a PDP-7, then named Unics as a somewhat treacherous pun on Multics, as the operating system for Space Travel, a game which required graphics to depict the motion of the planets. A PDP-7 was also the development system used during the development of MUMPS at MGH in Boston a few years earlier.
There are a few remaining PDP-7's still in operable condition. One under restoration in Oslo, Norway, has been thrown away.
Emulation
The PDP-7 can be emulated with SIMH. DECSys, Unix, Space Travel and some other software is available and can run on the emulator.
External links
- PDP-7 - Original PDP-7 documents
- Digital Equipment Corporation PDP-7 - Extensive site with a large amount of material
- "The famous PDP-7 comes to the rescue" (Bell Labs' Unix history)
- DIGITAL Computing Timeline - 1964 - PDP-7 entry
- PDP-7 Definition
