Thanks :) I do time the 6502 code using the MAME emulator, its debugger's trace feature, and a profiler I made. It's far from perfect (gets very confused by tricks like pha/pha/rts in the IIe ROM) but works under IIc emulation and allows me to precisely count cycles in my code: https://www.colino.net/wordpress/en/a2trace-debug-and-profil.../