Big Mess o’ Wires

I bought a used Augat wire wrap board off eBay. It’s a huge 2D array of hollow gold pins, 12″ x 7″. Chips are pushed into the component side of the board, fitting the legs of the chips into the hollow pins. I believe it’s intended to be a force fit, so no soldering. On the wiring side of the board, the pins project out about 3/4″ inch, and wire wrap tools are used to string wires between them.

The board has 26 pairs of columns spaced 0.3″ apart (the width of a normal DIP chip), each column 53 pins high. Typical 7400-series chips like the ones I’m using have about 20 pins, 10 on each side. If I packed them in tight, that would give me space for about 5 chips per column pair, or 130 chips total. However, some chips like the SRAM and EPROMs are double-width 0.6″. I also plan to use ZIF sockets for the EPROMs to make it easy to swap them in and out, which will eat up even more board space. Allowing for extra space between the chips and a handful of oversized components, I should still be able to fit at least 60-70 chips on the board, which should be more than enough to accomodate my design.

Since this board is used, it has lots of wire wrapping already in place that I’ll need to remove. It also has capacitors soldered between the power and ground pins across half the board. These are marked 0747WC446 in lettering so tiny, it makes me think it’s time to get reading glasses. I’m not sure what capacitance value they are. Maybe it’s best to pull them out? I’m not sure how to find out more about them.

The board also has 3 cable connectors along one side, and a couple of tabs for popping it in/out of a backplane. I’ll probably try to remove these, to get a cleaner look. Although the cable connectors might come in handy some day, if I decide to connect peripheral devices like a disk drive…