PDP11 I/O page memory map

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri Mar 2 07:37:47 CST 2018

    > From: Jerry Weiss

    > Typically execution of the RESET instruction in a user program is
    > treated as a NOP

Yeah, that's not documented in most PDP-11 CPU manuals, either. It's one of
the things that makes the PDP-11 impossible to virtualize; only HALT and SPL
trap, IIRC. M[TF]P[ID] doesn't, I think, and neither does WAIT or RT[IT],

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