Yeah hand written register shuffling always wins! It’s the comparisons that usually hurt the C performance - circle4 has twice as many.

The trade off is that some quick benchmarks show that it’s slower than the circle8 variant I’ve got - 226k ticks vs 197k ticks for 100,100,100. If you extract into a standalone, compile with +test and run with z88dk-ticks it reports a tick count on exit which is handy for tuning.

I see the Dog is still struggling to find the right combination of name and location.

Guess what machine uses the alternate register set for interrupts without saving them….temporarily bodged by using the 8080 runtime until I setup im2.

Screenshot from bringing it up yesterday, for once I didn’t use the ZX font!

It is weird being in contact with him again after all these years. I’m genuinely shocked but not entirely surprised by all the fuckwittery that’s been exposed since she died.

Nw. Agreed that it’s a fun thing to work through.

Just checking to see if you‘ve not spotted these: github.com/z88dk/z88dk/... - they should be used automatically with compiled code.