I really should dig out the Z80 based computer I made back in the mid 80s and write it up. I wire-wrapped the first version, it worked first time up, so I etched my own double-sided circuit board, and that also worked first time up.

4MHz Z80 with 8K RAM and 8K EPROM. Power transistors for switching motors on and off, opto-isolated infrared sensors for input, and it drove my micro-mouse.

I really should find it ...