I put the stack of four boards into a metal box measuring: 2" tall, 4" wide, 3" long. I cut the top off the box and replaced it with an acylic panel so the LEDs would be visible. The plan was to put this box on the back of my hand and run wires to audio and video effect circuits located on my forearm.

The back of the box showing the VGA connector and holes for running wires to the effect boards.

The stack of circuit boards. Top to bottom: LED Display, Light Detectors, Sample-and-holds, VGA signal generator.

I wanted to build audio/video modules that could be swapped out like the cartridges in an old game console. I used DB25 connectors for this. Signal wires connect to each DB25 in a parallel bus.

The main control system connected to the audio/video module bus. As you can see the wires running from the hand to forearm are getting pretty hairy. The wires needed were:

I wasn't running the Z position signal to the audio/video effect boards because at this point I wasn't planning on using those for anything other than mixing the volume levels and adding those would go over the DB25 pin count.