Use a colour code for your wires. The colour code that I chose was:
- Black for ground lines
- Red for Vcc lines
- Green for data lines to registers, to the ALU, to the RAM
- Yellow for address: PC to the ROMs, ROMs to the RAM
- Blue for clock signals. I also used blue for the analog
(NE556) side of things.
- White for the control lines
This helped me spot quite a few wiring mistakes. I think I only
shorted Vcc to ground once!