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Challenge - What mini (probably) did these logic boards come from?

billdeg

Technician
Joined
Nov 18, 2003
Messages
3,872
Location
Landenberg, PA USA
thm_DR240_RA240-2_front.jpg

Can you guess what computer these logic boards came from?

The only thing I can say for sure is
1) They're not from a Digital Equip Corp computer that I have ever seen (not the right size)
2) The Philco PD993659 chips have a silscreen date of 1968, 17th and 18th weeks.
3) These boards are exactly 14 cm tall (not including the handles)

More pictures:
http://vintagecomputer.net/browse_thread.cfm?id=499
 
Last edited:

billdeg

Technician
Joined
Nov 18, 2003
Messages
3,872
Location
Landenberg, PA USA
Does anyone have a DataGeneral logic chip to compare with? Both the mystery board and the FLIP CHIP (which is slightly shorter and thinner) have 18 pins on each side. What else would have 18 pins from 1968-69?
 

Chuck(G)

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Jan 11, 2007
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Location
Pacific Northwest, USA
I believe that the PD993659 is a DTL hex inverter, equivalent to an MC836L. Pinout similar to a 7404. The traces would seem to verify that.

My suspicion is that given the very limited amount of logic on each board, that they're not part of a computer at all. Perhaps some industrial control gear.
 
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