Retro Challenge – Half-time Catch-up

We’re at the halfway mark of the Retro Challenge, and there’s a slight lull in activity, so this seems like a good chance to catch up on what’s been done so far, and what’s still to come.

Firstly, a quick review of the challenge I set myself; write my name in LED lights.  These must, however, be controlled by a Z80 computer, which I’ve got to design and build myself, and written in assembly language which I need to learn.

Well, the start of the challenge saw me dive headlong in to KiCad, learning some of the intricacies of printed circuit board layout.  I’d used KiCad for a couple of little projects before, but certainly wouldn’t have described myself as competent.  I’m still not a master of it, but I’m a lot more familiar with it than I was.

I split my breadboard based Z80 down in to several modules, each of which will plug in to a Veroboard backplane.  6 of these have been designed and sent off for manufacture which will give me a basic Z80 computer that I can use via a terminal emulator.  The boards are;

  • CPU
  • Eprom (for BASIC eprom)
  • Eprom (for my Z80 code)
  • RAM
  • Clock
  • Serial I/O

2014-07-04 18.58.00 (more…)