Digital Equipment Corporation PDP-7/A - S#114

Applied Data Research (ADR), Princeton NJ

The PDP-7 Service list (1972) shows that machine #114 (DEC #999999) was a PDP-7/A shipped to Applied Data Research (ADR), Princeton, New Jersey in February 1966 and consisted of the following options -

Option	S#	Ship	DEC #	Notes
149	000075	0266	999999	4K core memory stack
149	000076	0266	000000	4K memory upgrade to 12K
177B	000034	0266	000000	Extended Arithmetic Element
550A	000049	0266	000000	DECtape dual magnetic tape transport control
CR01B	000005	0266	000000	Card Reader and Control
KA71A	000014	0266	000000	I/O device package
KA77A	000014	0266	000000	Processor unit
TU55	000114	0266	000000	Single DECtape transport
TU55	000116	0266	000000	Single DECtape transport
TU55	000236	0266	015585	Single DECtape transport

For descriptions of the above options see the full PDP-7 options list.

9/3/2016 - In a recent email Robert Supnik wrote about system #114 -
"Hi Mike.
I can give you the history of PDP-7/A serial #114 at Applied Data Research (ADR), Princeton, NJ, where I worked as a summer intern 1964-1968.
The PDP7 was bought as a program development environment or big brother to a DEC 338 (PDP8 + display subsystem), which was used for both real-time development and a government-funded research program. It had 16KW, EAE, card reader, DECtapes, a non-DEC printer from Potter, and a PDP7-PDP8 interprocessor link. It ran DECsys, DEC's primitive DECtape based OS. ADR enhanced DECsys to improve its IO and wrote cross-development tools and a PDP8 simulator for PDP8 development. Some of the sources still survive - the SimH[1] web site has the PDP8 simulator, for example. In 1969, ADR acquired a PDP-10 for development. After that, the PDP7 was no longer needed. In the early 70s, it was sent to the ADR branch office in Wakefield, MA, and eventually returned to DEC, where it was apparently scrapped.

I've talked to some of my former colleagues, and the PDP7 remained in use in Princeton into the early 70s, as it was the only way to assemble PDP8 programs using a macro assembler. It was probably shipped to Wakefield, MA in 1975 or thereabouts rather than the early 70s.

120 PDP-7 and PDP-7/A systems were forecast to be built in total, but the 1972 18-bit service list available (6.5Mb pdf download) only has details of the 99 known PDP-7 and PDP-7/A systems in the list at that time. We do not have any information about the possible remaining 21 systems, who they were delivered to or even if they actually existed.

The PDP-7 appeared to have sold well into Government research and University sectors with 11 systems shipped to the UK alone, almost 10% of the forecast production run! Serial numbers are concurrent for both PDP-7's and the PDP-7/A's, so the missing 21 could be of either type; however we are reasonably confident that the 99 systems shipped were the only ones that were ever built.

If you know of any information about any of the PDP-7 systems worldwide, options, location of existing systems, spare parts, ancillary bits, software, tapes or manuals, then please contact us.

Documents associated with PDP-7/A S#114 - None at this time

SimH - The Computer History Simulation Project is a loose Internet-based collective of people interested in restoring historically significant computer hardware and software systems by simulation. The goal of the project is to create highly portable system simulators and to publish them as freeware on the Internet, with freely available copies of significant or representative software - weblink [back] [top]