David Brant wrote: > Just to put a spanner in the works. JP's are faster in external memory.
You're right! External memory is uncontended, so it's as fast as the ROM. SimCoupe does already implement that correctly, so it's just my memory at fault. I ran a test incrementing BC in a tight loop between the end of active frame interrupt and the following interrupt. The counts were: External RAM: 11965 Internal RAM, screen off: 9971 Internal RAM, screen on: 8915 Internal RAM, mode 1: 8028 It seems well worth using if it's present, even if it doesn't help so much with display code. It should give a worthwhile free boost to my various 6502-based emulators though. Si
