[Simh] More VAX Simulators

[Matt Burke]

I've put my vax4xx (VAX Workstations) branch online which is a series of
VAX simulators that are based on a similar architecture. This originally
started as the MicroVAX/VAXstation 2000 simulator that I release back in
2011, but it has been developed substantially since then to include more
feature and another 11 models of VAX. The list now includes:

MicroVAX/VAXststion 2000
InfoServer 100
InfoServer 150 VXT
MicroVAX 3100 M10/M20
MicroVAX 3100 M10e/M20e
VAXstation 3100 M30
VAXstation 3100 M38
VAXstation 3100 M76
VAXstation 4000 M60
MicroVAX 3100 M80
VAXstation 4000 VLC
InfoServer 1000

Several new devices have been developed to support these simulations
which include:

(rd) HDC9224 MFM disk controller
(rz) NCR5380 SCSI controller
(rz) NCR53C94 SCSI controller
(xs) LANCE Ethernet controller
(vc) Monochrome video controller
(va) GPX video option (partly working)
(ve) SPX video option (work in progress)

This branch is still under development. The lists above are more or less
in order in terms of how fully developed they are. The MicroVAX 2000 is
pretty much complete whereas the VAXstation 4000 M60 lacks video, sound
etc. but is still usable.

The code is available from:

https://github.com/9track/simh/tree/vax4xx

Windows executables are available at:

http://www.9track.net/simh/vax4xx/

Please try them out and let me know if you have any questions.

Thanks,

Matt