Ian Collier wrote: > Correct me if I'm wrong but this doesn't look anything like the code you > were supposed to be attaching, and it just says "not understood" when > executed.
Yeah, I saved it from Outlook, viewed it as binary and it started like this... DB A4 B8 32 22 C4 A4 99 32 1E C4 A4 9A 32 55 C4 ... which doesn't look like valid Z80 code, even ignoring the CRLF at the end! On a related matter, I'm a bit confused by how the t-state timings in the Z80 core are calculated. Most are what I expect, but some don't match the official timings I'm used to. e.g. LD r,r' says 8 t-states, but the docs I have say it's 7. JR c,e takes 8 t-states if the condition is not met and 12 if it is, but the docs I have say it's 7 and 13 respectively. etc. Could someone explain the 4 t-state rounding? (machine cycles?) I could understand it being rounded up, but the conditional relative jump is slightly shorter. I've always done video effects with official timings, and manual tweaks if necessary! Coincidentally I spent a couple of hours this morning going through code putting the offical values in to see whether it made any difference with a couple of programs I've got that are suffering from minor timing problems. I'm not quite finished so I haven't tried it yet. I'm now wondering whether I should have bothered doing it as it might not be any use - they're probably like that for a good reason! Si
