> Or perhaps the busy-wait could be done from an emulated instruction on
> real vax hardware.  Then SIMH could implement the instruction in a more
> efficent way, and you don't need any special checks.  (Just an idea,
> I'm not volunteering to write any code for this :-)

Might as well just document the sequence of instructions NetBSD uses for
the busy wait.  Assuming it's short and simple, SIMH can easily be
modified to detect it and DTRT.