Digital Equipment Corporation PDP-7 Serial number #2

Digital Equipment Corporation PDP-7 - S# 2
Stanford University

Image courtesy of Professor Harlan Lefevre, University of Oregon, click for larger image

Stanford University Core Store
Image ©2011 Professor Harlan Lefevre

Recent information from Professor Harlan Lefevre at the University of Oregon has shed a little light on the ultimate demise of the very first production PDP–7 computer shipped to Stanford University.

Delivered in April 1965 that machine would appear to have been de-commissioned and dismantled in 1977 with many of the parts and least one of the memory stacks (pictured) being shipped to the University of Oregon as spares for their machine (S# 113). The memory stack pictured is from the Stamford machine, it is 4096 18-bit words or just over 73Kb of storage and weighs 3.6Kg (8lb) and was priced around $12,000.

Stanford University machine was a PDP-7 (S# 2) and had options - 7, 34, 75D, 149, 172, 177, 197, 370, 444B, 550A, 555 and 649.

The PDP-7 Service list (1972) shows that machine #2 was shipped to the Stanford University in April 1965 and consisted of the following options -

Option	S#	Ship	DEC #	Notes
7	000002	?	999999	?
34	000004		000000	Oscilloscope display control only
75D	000002		000000	Perforated paper tape punch and control
149	000004		000000	Core memory module 8K, extends in 8K blocks
172	000002		000000	Automatic priority interrupt
177	000003		000000	Extended Arithmetic Element
197	000001		000000	Memory increment control
370	000139	1265	000139	High speed Photomultiplier light pen
444B	000002		000000	Perforated paper tape reader and control
550A	16	0200		DECtape control (up to 4x 555's)
555	000034		000000	DECtape dual magnetic tape transport
649	000002		999999	Teletype control

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

120 PDP-7 and PDP-7A systems were forecast to be built in total, but at this time we do not have any information about the possible remaining 21 systems or who they were delivered to. The 1972 18-bit service list, available here (6.5Mb pdf), details the 99 known PDP-7 and PDP-7A systems in the list at that time. 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-7A's, so the missing 21 could be of either type, however we are reasonably confident that the 99 systems shipped were the only ones 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 let us know here.

Documents associated with PDP-7 S# 2 - None at this time