Z180 Mark IV Single Board Computer

There is a thriving community of enthusiasts who design and build their own computers from scratch, not just buying ready-built parts, but laying out pcb's, writing the firmware etc.

Check out: https://www.retrobrewcomputers.org/doku.php

A few years back I thought I'd have a go at assembling my own system from some of the designs on that site. I chose the Z180 Mark IV, a turbocharged variant of the venerable Z80 8bit processor with a memory management unit, 512KBytes of RAM, a multi-slot backplane and modern(ish!) storage, keyboard and display support.

8 slot ECB backplane board

… see if you can spot the deliberate mistake with the 2 reversed slots

Building and programming the PropIO peripheral controller

Testing VGA and keyboard functionality of the peripheral controller

Running the Z180 Mark IV test rom

Output from UNA BIOS on the Mark IV, using a traditional serial terminal

Output from UNA BIOS on the Mark IV, using the peripheral controller board