Re: ZX81 ULA-in-a-CPLD
Posted: Sat Nov 10, 2018 9:20 pm
No /IORQ, no /NMI ...
Discussion forums for users of the Sinclair ZX80 / ZX81 and their clones
Only eight.Andy Rea wrote: ↑Sat Nov 10, 2018 9:23 pmwhat i wanna know is what the heck is the ~IORQ line doing after the nmi stops... what in the world would cause so many io instructions ?
how many lines has your logic analyser got ? i'm thinking about probing the entire data bus and ~m1 in addition to the other lines then you can decode the exact instruction prior to a failure