UniProbe - Introduction

Parent Category: Tools Category: UniProbe - an UNIBUS signal adapter Written by Administrator

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

No vapor-ware!

uniprobe leds wires 2

Such an adapter needs to fulfill these criteria:

  1. must be pluggable into UNIBUS backplanes, and must not break the UNIBUS signal or termination chain.
  2. should have some lights to visualize bus traffic and error conditions.
  3. must have some means to connect logic analyzer probes to UNIBUS signals.
  4. lights and probes must be accessible even if the adapter is completely hidden in the card cage.
  5. be mechanically robust and compact enough to make not more problems than it helps solving.

My typical setups always violated condition 5:


Now I can show it my mom:

uniprobe la