DEC PDP-8/a Restoration Log

4/30/20

I brought the 3x CPU boards, 2x core memory boards, and the programmer's console home so I could use one of my personal PDP-8/a systems to test and debug these parts

I have found 3x defective ICs so far, and should have replacements next week

  • Front board, E10 SN7408, pin 8 has a weak pulldown
  • Register board, E15 SN74174 latch doesn't latch
  • Register board, E26 SN7475, latch does not latch

The 2x 40-pin ribbon cables that connects the programmer's console to the M8316 board had wire-wrap wires added.

It looks like they were trying to fix bad cables.

I also found that the programmer's console cables in my personal 8/a were bad