VME to multibus adaptors. (VME = master, multibus = slave)

Sat May 27 05:16:59 AEST 1989

We have some image processing board which reside in a multibus cardframe,
and we would like to interface them to both a Sun and a DECstation 3100
(not both at the same time!).

Does anyone know of a source of VMEbus to multibus repeater cards which
could help us with this problem?  What appears to be required is a VME
card which plugs into the Sun or DECstation, a second card which plugs
into the multibus cardframe, and a bundle of cables which link the two
cards together.  I have a multibus to multibus repeater which we use to
allow our old Sun2s to talk to the system, and I know that VMEbus to
VMEbus repeaters exist (as used by Datacube, for example, to link their
MaxVideo systems to Suns).

What are the issues in protocol conversion between these two busses?
Presumably the multibus (in 20 bit address space on our system) in 16 bits
mode could appear as a portion of the VMEbus space in A24D16 or A32D16
modes.  Any data byte order problem is easily taken care of in software,
at least for our application.

An additional question - is there a mailing list equivalent to SunSpots
for users of the DECstation?  (Sadly DEC's discount schedule for
universities appears better than Sun's...)

Neil/.

	Neil%Teleos.com at AI.SRI.com
     ...!decwrl!argosy!teleos!Neil