Wire wrap sockets and wire have gotten expensive. I’ll have to order some later. So for this project I’ll have to stick with soldering. It’s slow work.
The first thing I did was wire all 60 signal pins and power to a female pin header. This will let me test each new part of the circuit on a breadboard before soldering it into place – an important step I’ve forgotten too many times in the past.
I’ve drawn up a schematic in Eagle with things I would like to test, based on what I have on-hand already: 64k of SRAM, Zilog Z8530 Serial Communications Controller, Compact Flash in IDE mode, and of course an ISA-like interface for my LED display board. If I have room left on the board, and can figure out the logic, I have some 30-pin SIMMs I’d love to throw in.
From the schematic, I like to draw a functional diagram in the style of the one Daniel Kottke drew for the original Macintosh. I use graph paper, with one square representing four holes on the board. I’ll mark out the box of each chip and name each signal. I find it much more useful than a traditional schematic when actually building something, and it lets me plan how everything will fit on the board. I arranged the RAM, ROM, and register several times on paper to optimize wiring based on proximity. I’m sure I could do that in Eagle too, but sometimes I just think better putting pencil to paper.