On Jan 14, 14:26, Ethan Dicks wrote: There are two relevant differences. The first is that on the 68000 (and 68008), reading the system byte in the status register isn't privileged, so MOVESR works in user mode as well as supervisor mode. In the 68010, that was corrected and an extra opcode was added to allow reading the user byte (condition codes) in user mode. The second difference is that the 68010 has the VBR (vector base register) so different interrupt/trap vectors can be used in different modes; the vector base is fixed in the 68000/68008. There's no difference in things like address range, modes, MMU interfacing, etc. Those changes came with the 68020. The other changes were improvement to the microcode, which made loops faster. -- Pete Peter Turnbull Network Manager University of York