 | |
 A modified PDP-7 under restoration inOslo, Norway | |
| Manufacturer | Digital Equipment Corporation |
|---|---|
| Product family | Programmed Data Processor |
| Type | Minicomputer |
| Release date | 1965; 60 years ago (1965) |
| Introductory price | US$72,000 (equivalent to $718,403 in 2024) |
| Units sold | 120[1][2] |
| Units shipped | 120[2] |
| Operating system | DECsys,Unix (as "Unics") |
| Memory | 4K words(9.2 KB) (expandable up to64K words(144 KB).)[1] |
| Storage | Paper-tape and dual transportDECtape drives (type 555) |
| Display | Printer |
| Input | Keyboard |
| Platform | PDP 18-bit |
| Backward compatibility | PDP-1 |
| Predecessor | PDP-4 |
| Successor | PDP-9 |
ThePDP-7 is an18-bitminicomputer produced byDigital Equipment Corporation as part of thePDP series. Introduced in 1964,[3]: p.8 [4] shipped since 1965, it was the first[5] to use theirFlip-Chip technology. With a cost ofUS$72,000, it was cheap but powerful by the standards of the time. The PDP-7 is the third of Digital's 18-bit machines, with essentially the sameinstruction set architecture as thePDP-4 and thePDP-9.
The PDP-7 was the firstwire-wrapped PDP computer. The computer has a memory cycle time of1.75 µs and an add time of4 µs.Input/output (I/O) includes a keyboard, printer,punched tape and dual transportDECtape drives (type 555).[6] The standardcore memory capacity is4K words(9 KB) but expandable up to64K words(144 KB).[1]
The PDP-7 weighs about 1,100 pounds (500 kg).[7]
DECsys, the first operating system for DEC's 18-bit computer family (and DEC's first operating system for a computer smaller than its 36-bit timesharing systems), was introduced in 1965. It provides an interactive, single user, program development environment forFortran andassembly language programs.[8]
In 1969,Ken Thompson wrote the firstUNIX system, then named Unics as a pun onMultics despite only using two design elements from Multics,[9][10] in assembly language on a PDP-7,[11] as the operating system forSpace Travel, a game which requires graphics to depict the motion of the planets. A PDP-7 was also the development system used during the development ofMUMPS atMGH inBoston a few years earlier.
The PDP-7 was described as "highly successful."[12] A combined total of 120 of the PDP-7 and PDP-7A were sold.[3]: p.8 ADEC publication states that the first units shipped to customers in November 1964.
Eleven systems were shipped to the UK.[5]
At least four PDP-7s were confirmed to still exist as of 2011[5] and a fifth was discovered in 2017.[13]
A PDP-7A (serial number 115) was under restoration inOslo, Norway;[14] a second PDP-7A (serial number 113) previously located at theUniversity of Oregon in its Nuclear Physics laboratory was at theLiving Computer Museum in Seattle, Washington and is completely restored to running condition after being disassembled for transport;[15] Another PDP-7 (serial number 47) is known to be in the collection of Max Burnet near Sydney, Australia, a fourth PDP-7 (serial number 33) is in storage at theComputer History Museum in Mountain View, California and a fifth PDP-7 (serial number 129) belonging to Fred Yerian is also located at the Museum, and has been demonstrated running Unix version 0 and compiling aB program.[13]
Ultimately, 120 PDP-7s were produced and sold.
a good case can be made that UNIX is in essence a modern implementation of MIT's CTSS system
The things that I [Ken Thompson] liked [about Multics] enough to actually take were the hierarchical file system and the shell
