[Simh] several SIMH instances

[Kevin Handy]

Paul Hardy wrote:

> That is a good idea, but an answer to a different problem. I (and I 
> suspect
>
>most SIMH users) don't want to slow down the simulation, but be able to have 
>it share a host machine without hogging resources.
>
>I'd like SIMH to use as much resources as are freely available (e.g. boot 
>and run faster than any VAX that actually existed), but continue to run in 
>the background if largely idle, while I get on with 'real work' on the same 
>host machine (in my case a Windows laptop).
>  
>
The current 'debug/test' version of simh has this OS idle loop code
(it looks for specific code for each OS supported), but it doesn't
like Linux 2.6 due to the 250 HZ rate. Bypassing that test, it
creates a VMS emulation that idles on my 600Mhz machine at
< 1% of CPU usage when it's not doing anything. This is MUCH
nicer than idling at 100%.

The idle-loop code can be turned on/off as desired.

>The idle loop detection idea seems perfect for that and I'd like to see it 
>in the standard pre-built executables as soon as possible! Has there been 
>any recent progress towards this?
>  
>