[Simh] Simulator lockup when booting RSX-11/M+ V4.6 BL87 baseline system disk with insufficient memory

[Christian Gauger-Cosgrove]

Hello:

I've noticed an odd issue. When booting the aforementioned baseline
RSX-11/M+ disk, with 256K of memory, RSX-11 doesn't have enough RAM to
work when it tries to run the startup script. This happens as the
system doesn't have enough memory to allocate a checkpoint space; so
RSX-11 gets stuck in an infinite loop repeating:
<TIME>  *** GEN    Checkpoint space allocation failure
Where <TIME> is the current time in HH:MM:SS format. The CPU is
working, as you can see the time field counting properly. However, the
simulator completely locks up otherwise; you can't Ctrl+E to the sim>
prompt, you can't Ctrl+C or Ctrl+Z the program within RSX-11 itself.
Trying to exit the SIMH simulator doesn't work. The only way to kill
it is via the task manager (on Windows).

I'm using the 14 day old Windows binary. Currently this is happening
on a Windows 7 Professional SP1 workstation at my university. I'll
have to check on my W7 Pro SP1 desktop at home, just to see if it is a
problem with this specific machine, or with the executable itself.


Regards,
Christian

-- 
Christian M. Gauger-Cosgrove
STCKON08DS0
Contact information available upon request.