[Simh] Slow startup/shutdown...of the VMS simulator

[Davis Johnson]

Villy Madsen wrote:

>Does anyone have a suggesting for an existing device that I could "misuse" -
>just to get a one bit channel between the SCP and VMS ??
>
>Thanks
>
>Villy
>
>  
>
I don't know the VAX hardly at all, but some machines have a power 
failure warning interrupt of some sort. Usually (in the real hardware) 
it doesn't give you enough time to do an OS shutdown. OS/32 (Interdata 
7/32, 8/32, Perkin-Elmer/Concurrent 3200) would save the processor 
internal state to main memory. When power was restored the microcode 
would kick a power restoration handler in the OS that would restore 
processor state and continue execution.

Assuming an equivalent facility in the VAX and VMS you could possibly 
have a VMS session that would survive a host OS reboot. You would need 
to save the memory image to disk, and restore it on restart.

Curses on you for sugesting somthing else that would be interesting to do.