[Simh] Representative Instruction Execution Timing

[Dennis Boone]

 > I am trying to figure out how to slow down the SIMH PDP-8 simulator such
 > that the instructions are executed with similar timing to that of a real
 > PDP-8.  I have found that that even with throttling set very low, the
 > PDP-8 simulator executes much, much faster than a real PDP-8.

There are some software tools, e.g. IntervalZero, that purport to add
real-time scheduling to Windows.  Assuming you could get SIMH to build
for one of them, you might be able to extend it a bit to release its
timeslice between emulated instructions and get re-scheduled at an
appropriate time.  That would seem to meet most of the constraints you
mentioned (keeping windows, not running the cpu at 100% all the time,
etcetera), assuming you weren't talking about a tool like this when you
said "cannot change to a real-time environment."

De