[GreenKeys] More BRPE progress: a schematic

Jones, Douglas W douglas-w-jones at uiowa.edu
Fri Apr 18 15:16:46 EDT 2025


Googling around, I found some BRPE schematics that differed enough from each other that I decided I needed to do some reverse engineering on my BRPE before I tried to connect anything to it.

I've put a schematic up for my machine at:
-- https://homepage.cs.uiowa.edu/~jones/pdp8/UI-8/log2025.shtml#2025-04-17

I included a drawing of the face of the Amphenol Micro Ribbon connector at the back of the machine giving the pinout -- and I took the time to measure the pulses from the electromagnetic pickup to figure out the polarity of the pulses (positive before negative or negative before positive), supposing that someone cares about that.

                Doug Jones


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