What is it?

This is a pretty simple breakout board for the right-angle PCB-mount plugs and receptacles (AKA 24 pin "Centronics" or AMP CHAMP or Amphenol 57 series, though not these probably won't work if you're looking for a general purpose breakout for these connectors since the GPIB ground pins are wired together) which are used for the GPIB/HPIB/IEEE-488 interface you might find on the back of old test equipment.

Currently, this listing is for the PCB ONLY. GPIB connectors and 0.1in headers are not provided: bring your own, connectors are only shown as examples. These connectors seem standard enough that anything that looks similar should fit, but if you're paranoid you can compare the footprints: this PCB is open source.

The board has been designed with silkscreen on both sides so that you can use either a plug or a receptacle connector. Two spots for 0.1in pitch 2x12 connectors are provided for easy access to signals for projects or probing. I designed this in order to develop a microcontroller based USB-GPIB converter while also having access for my logic analyzer.

The GPIB shield pin and the connector mounting holes are connected, and connected to ground with a normally-closed solder jumper- I believe this is the optimal configuration, but isn't it nice to have the choice?