> Depends on the bus interface. For the 68000 it's dead easy to withhold /DTACK for an
> arbitrary number of cycles while the hardware being accessed does stuff
Sounds like the equivalent on the PC to the "+IO CH RDY" line on the ISA bus. A peripherial can pull this low to suspend one of the phases of a bus access cycle, introducing wait states. That's not quite the same as interrupting the CPU on an arbitrary cycle, though - the execution unit can keep on running during these wait states, and the bus interface unit can only be suspended in one of its phases.