heh. i also programmed a stepper motor in ~1985 (after building the driver board). but it was z80-based (and it never ran smoothly - when i left i think they

heh. i also programmed a stepper motor in ~1985 (after building the driver board). but it was z80-based (and it never ran smoothly - when i left i think they were going to try adding some noise to the timing, but that didn't sound likely to me - more likely i had a crossed wire in the hardware...). anyway, i am pretty sure i had an assembler (and this was working for a one-man company in the backwoods of n yorkshire). why were you hand assembling?