UniProbe - an UNIBUS signal adapter

When repairing DEC PDP-11s there's always the need to see whats happening on the main system bus. On older 11s this is the UNIBUS.

After several try-and-error cycles, I think I now have the perfect signal adapter for UNIBUS ... calling it "UniProbe". In KiCAD 3D rendering it looks like this:

uniprobe3d total

UniProbe has these features:

  • can be built to plug into Standard UNIBUS or Modified UNIBUS slots.
  • can be built to be a PDP-11/34 M9302 or a simple M930 terminator.
  • LEDs for all 56 UNIBUS signals on the card edge.
  • Logic analyzer probe plugs and a patch board area for measuring the signals.

Read on!