[Simh] External bus interface

[Paul Koning]

> On Jan 18, 2018, at 5:12 AM, Lars Brinkhoff <lars at nocrew.org> wrote:
> 
> Hello,
> 
> I wrote a GitHub issue about this, but maybe it's better to bring it up
> for discussion on the mailing list.  So I'll copy the text here:
> 
> Richard Cornwell's KA10 simulator is getting ready.  At MIT, there were
> PDP-11s connected to the PDP-10 memory and I/O busses.  The 11s acted as
> dedicated I/O processors.  Some of us are interested in recreating
> configurations similar to this.  For example, MIT-AI had a PDP-11
> connected to control a number of graphical terminals called Knight TVs.
> And another PDP-11 for CHAOS networking.
> 
> To hook up separate simulator processes this way, I suppose there should
> be some kind of bus interface for SIMH.  The interface would have to
> support memory transfers, interrupt signals, etc.
> 
> Would it be feasible to create such a bus interface?

I think this was done already for PDP-15 to PDP-11 hookup, but I don't know any of the details.  It seems like something that would be easier with threads rather than processes, but it should be doable either way.

	paul