PDP8A Power Distribution Board

Marco Rauhut marco at familie-rauhut.eu
Sun Oct 21 04:50:55 CDT 2018


Hello alltogether,

i am restoring a PDP8A at the moment. The machine got a problem in the 
Powersupply. I think one of the emergency ciruits trigger a shutdown of 
PSU. In tracing this isue i hab two questions.

My 8A`s manufacturing year is 1977. It`s model is 8A620. On Bitsavers i 
found a matching shematic for the BA8C Power distribution Board from 
1976 (File: EK-8A002-MM-002_PDP-8A_Miniprocessor_Users_Manual_Dec76.pdf 
page 597). The Board Number is 5412000-0-1.

My first question is if somone has the Board Layout with it's component 
locations?

My second question is about the DEC4011 Chips. As i inspected the Board 
i found the DEC4011 Chips. First i think they are the standard CMOS 4011 
quad two-input NAND`s. In the shematic it look more like a four 
Transistor array. Did anyone know somthing aput these Chips? Are there 
any equivalent parts? Have anyone a Datasheet of it?

Marco





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