Sunday, 12 July 2009

Serial IO Working...well sort of!

I've made up a bit of ground on my Serial I/O card today and managed to print a few messages from the Z80 to a computer running Hyperterm in both 3-wire (no handshaking) and 5-wire (RTS/CTS) handshaking - however I've can only get 3-wire working in the opposite direction. I think I need to bridge some signals at the PC end to use just RTS/CTS or possibly use different signals from the SIO instead of its own RTS.

On the memory glitches I've now got it working 100% fine for all but the first bank which goes through a lot of different gates to get the boot rom select to work, I think I may have too many gates in the path and it is not settling quickly enough so I may have to rethink that bit!


  1. any chance of some schematics to browse over?


  2. Yup, they're up - not sure I've got the handshaking 100% yet, just about to try it out.

    I've never managed to get 8-bit computers to play nicely with PC's as they use slightly different meanings for all the control signals.