Kearney & Trecker Core memory, may be PDP8

FWIW I'm pretty sure these boards are for a PDP-8/A chassis. See below... On 12/11/2014 07:13, Paul Anderson wrote: Not necessarily, but it's extremely hard to imagine how it could possibly be a Unibus board with four edge connectors on ABCD rather than CDEF, and the only QBus chassis those boards would fit would be an H909 with a DDV11 backplane. So, I'd agree it's highly unlikely to be any sort of -11. I believe this system was based on a PDP-8/A because: - the memory doesn't look /quite/ like my 11/34 core but does look like 12-bit PDP-8/A memory; - the seller has several other cards from what seem to be the same system, or at least the same type, some of which have I/O connectors just above where the EF fingers would be - as found on some PDP-8/A boards, but not AFAIK on any others; - the pattern of power/ground connections visible on the solder side of some exactly match the Omnibus layout but not Unibus or Qbus; - a friend has a similar CNC system, built in a PDP-8/A chassis, with a papertape reader exactly the same as the one in one of the seller's other auctions. There's a picture of it here, taken at DEC Legacy 2011: http://wickensonline.co.uk/declegacy/node/129 It's a long time since I looked inside that system, so I can't be sure how many of its boards were custom items, or if they match the listings. Unfortunately I can't go and look for a week or two :-(