As a followup to my post on interrupts, I decided to have a go at modifying Grant Searle’s I/O routines for his 7-chip z80 Computer. After quite a bit of work, I had the routines in his handler changed to conform with his code (at least I think), and function as intended (at least as far as I was able to test).
The next task was to try it with his modified version of the Nascom Rom. And, after splicing the code, I compiled and tested…..and tested…..and tested…..
Well, the short of it is that it kind of works. The video above says it all. The serial routines seem to work fine up until BASIC starts up. And at that point, my serial routines work fine, but there is some disconnect with Grant’s code that either doesn’t like my own code, or is simply amiss.
The video really does say it all. If anyone has any ideas, or has ported Grants work over to using either the DART or SIO, I’d love to see your code. Help a brother out… But seriously, watch the video. It’s hilarious….