Digital Equipment Corporation PDP–7 - S#2

Image courtesy of Professor Harlan Lefevre, University of Oregon, click for larger image
Stanford University Core Store
©2011 Harlan Lefevre
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Stanford University

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.

The 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 –

OptionS#ShipDEC #Notes
7000002 999999?
34000004 000000Oscilloscope display control only
75D000002 000000Perforated paper tape punch and control
149000004 000000Core memory module 8K, extends in 8K blocks
172000002 000000Automatic priority interrupt
177000003 000000Extended Arithmetic Element
197000001 000000Memory increment control
3700001391265000139High speed Photomultiplier light pen
444B000002 000000Perforated paper tape reader and control
550A160200 DECtape control (up to 4x 555's)
555000034 000000DECtape dual magnetic tape transport
649000002 999999Teletype control

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

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 S#2 - None at this time

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