Yes, but a REAL resident debug monitor with features as included in the old '70's DDT that came with CP/M, or MSDOS' DEBUG.COM, will allow debugging I/O interfaces in real time, while most ICE's can't do that because they're too slow, and simulators don't generally have a way of synchronizing simulated I/O (if they support that at all) with the CPU simulation.

Nothing else works quite like a resident debug monitor, particularly in situations where you can't conveniently introduce an ICE, e.g. where the CPU lives in programmable logic.

RE