Digital Equipment Corporation PDP–7/A - S#112

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	Image ©2009 Edinburgh Computer History Society Click any image for a larger version
	S#112 during delivery Image ©2009 Edinburgh Computer History Society

Edinburgh University (UK)

The PDP–7 Service list (1972) shows that machine #112 was shipped to Edinburgh University in February 1966 and consisted of the following options –

Option	S#	Ship	DEC #	Notes
149	000073	0168	000000	4K core memory stack
175	000054	0168	030862	Information collector expansion.
177B	000046	0268	030862	Extended arithmetic element
340	000025		000000	Precision Incremental CRT Display
347C	000007		000000	340 Display Subroutine Interface
354	000008		015882	Unknown option
370	000112		000000	Photomultiplier Light Pen
550	000080	0168	030862	DECtape control, (up to 4x 555's)
KA71	000012		000000	I/O device package
KA77	000012		000000	Processor unit
KB03	000029	0168	030862	Device selector expansion
TU55	000368	0168	030862	Single DECtape transport
TU55	000398	0168	030862	Single DECtape transport
TU55	003416		080544	Single DECtape transport

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

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#112 - (see below)

A document was found at the Edinburgh Computer History Project which briefly describes the use that the Edinburgh University's PDP–7/A Computer was put to. The website however went offline for a while following technical problems, it is currently online but not in a very accessible form, we have copy of the relevant document.
"A PDP7 with a model 340 (?) vector graphics display and later a Honeywell 316 were linked to the 4130 through a "high–speed" data link (into the ATU of the 4130 for devotees). The PDP7 was used by John Oldfield and his group for early CAD system research."

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.