Scott Lawrence has written an article detailing his Z80 homebuilt computer, the RC2014:
The RetroChallenge is upon us again!
This time around, I plan on working on my Z80 homebuilt computer, the RC2014. (Website for RC2014, Order a RC2014) For a few months now, I’ve had my RC-2014 computer built, and modified to be an RC2014/LL computer. What this means is, is that I have some modified modules using no additional external hardware.
The above picture shows my RC2014/LL system with its extra RAM module, and the C0 Serial expansion board to the left, with the SD card interface board (SSDD1) on it.
Project info at Scott Lawrence’ blog.