[Simh] CI750 tech docs and VAX firmware

[Paul Koning]

> On Mar 9, 2017, at 12:27 PM, Timothe Litt <litt at ieee.org> wrote:
> 
> ..
> With respect to an earlier question about CI emulation:  The best approach may be to emulate it as multicast ethernet.  Setup a couple of groups for each star coupler.  Each coupler supports up to 32 nodes.  For VMS, half o them hosts, half storage.  CI is a 50Mb/s (might be 70, but I remember 50 from the initial doc) CSMA/CD bus.

70 Mb/s is the number I always saw.

>  The cabling is redundant (A & B cables), so assign one MC group to each per star.  (Yes, there are DECnet drivers for on multiple OSs.  I think it was considered a multipoint medium with addresses related to (CI) node numbers rather than an ethernet (broadcast) - but it's been a while.)

I don't think DECnet ever supported CI.  It certainly doesn't show up in the DECnet architecture specs anywhere.

	paul