Z80 Project Mark 2: More Dodgy Mods
Last updated: 06 Oct 2009 - 15:18
So, I got some lights flashing over two weeks ago and then went quiet, "what's been going on?" you may well ask. Once I got the lights flashing, I wrote another demo that does a chase across the row of LEDs, this would show up if any of the tracks on the data bus were shorted as each led is lit individually and is driven by a single bus line. Once I'd done that I started work on the serial port code for the PIC's onboard serial port. The basic send and interrupt on receive code is working so it echoes each character it receives back at the moment. However to test the code in the PIC I needed a nice serial-terminal application so decided to write one with PyGTK, threading and python-serial. I've got that working fairly well now, once I've developed it a bit more I will probably release it somewhere.
However, I hit something of a problem while studying data sheets. It explains why no one has tried this whole running DMA while the Z80 is in reset idea before. Basically while the