[Simh] CI Code Released

[Matt Burke]

As Mark mentioned recently I've already done quite a bit of work on a CI
and DSSI simulation for the VAX. I originally started working on this
quite a few years ago and I did have it mostly working at one point.

I've taken my latest development version and tried to tidy it up a bit
and merge it into the latest Simh code. I haven't had chance to work on
this properly for quite a while now so I'm just going to release what
I've got as there seems to be quite a bit of interest. The result is in
a branch on Github:

https://github.com/9track/simh/tree/CI

Unfortunately this latest version does not quite work. It seems that
something got broken in one of the more recent updates. I might get some
time later this week to debug it. I don't think it will be anything major.

The other problem is that this was based on a much earlier release of
Simh and the sim_sock module has changed beyond recognition. To allow
people to be able to build this I've temporarily bundled the old
sim_sock into the repo as ci_sock with some changed to add multicast
sockets.

To get the CI port to work you will need console media containing the
microcode. The O/S will not attempt to initialise the port unless it
finds these files. The actual microcode is not used by the simulation.
For convenience I've uploaded some suitable console images here:

http://www.9rack.net/simh/750console.zip
http://www.9rack.net/simh/780console.zip
http://www.9rack.net/simh/8600console.zip

To setup the CI port use commands similar the the following:

; Enable the CI port
sim> set ci en

; Set the port number (range 0-15). This would be set by jumpers on the
real adapter
sim> set ci node=4

; Set the (unique) TCP port number for virtual circuits. Other
simulators will use this port to establish virtual circuits to this node
sim> set ci port=3818

; Attach the CI port to a UDP multicast group. This will be used so that
nodes can 'discover' each other prior to a virtual circuit being opened.
This should be the same address and port on all nodes belonging to the
same CI. The address should be in the range 239.0.0.x
sim> att ci 239.0.0.37:3812

Feel free to ask any questions and I'll try to help where I can.

The sources of information I used when developing this were:

Chapter 5 of EY-9222E-SA-0001 - VAXcluster Maintenance Student Workbook
Volume 1
EK-CI750-TD - CI750 Hardware Technical Description
VMS source listings
Ultrix source listings

There are more simulations in the pipeline (HSC70, VAX 8200, VAXstation
2000, VAXstation 3100...). Hopefully I'll get these released soon too.

Matt