I don't know much about timing on the ZX81 and the Z80 processor. I do however have Rodnay Zaks Programming the Z80 where is states that LD r,n is 2 M cycles and 7 T states. Not that this makes much sense to me.nollkolltroll wrote: ↑Sat Apr 28, 2018 8:34 pm I seem to remember something about the Lambda using 208 cycles per line, whereas the ZX81 uses 207. This is strictly a vague feeling, not something to rely on...
So I'm guessing I need to find an instruction in the loop that draws the line, and replace a 2 M cycle instruction with a 3 M instruction, or replace a 4 M with a 5 M?