VAX 4000-100 QBUS cables

Peter Coghlan cctalk at
Mon Nov 28 16:34:09 CST 2016

On Mon, Nov 28, 2016 at 19:53 +01:00, Pontus Pihlgren <pontus at> wrote:
> On Mon, Nov 28, 2016 at 08:39:03AM -0800, Glen Slick wrote:
> > On Mon, Nov 28, 2016 at 7:34 AM, Pontus Pihlgren <pontus at> wrote:
> > >
> > > And I forgot, that is just the cable. I suppose you need a matching
> > > board in the QBUS box. Any idea what part number that might be?
> > 
> > I have an M9405-PA. It has one male and one female 3-row 50-pin
> > D-shell connector. I believe that is the board in the expansion
> > chassis you would cable up to the VAX 4000. It is an s-box handle
> > board.
> > 
> > Looks like this one:
> >
> Ah, according to my inventory I should have one :D Now I must go look for 
> the cable.
> Thanks everybody!
> Pontus

If I may jump in at the end of this thread, I am also interested in playing
with the QBUS capability of my VAX 4000-100A which has the two 50-pin D
connectors as discussed.

I don't want to be able to use regular QBUS cards so I don't envisage the
need for an expansion chassis.  What I would like to do is to construct a
simple experimental QBUS device which could enable the VAX to talk to the
outside world in the way of a few output lines that could drive relays or
something similar.

Not having an expansion chassis means that I would not need to get the
cables designed to connect to it and if I had the pinout of the D connectors,
assuming it is not too hard to track down suitable connectirs, I could
hopefully make up cables to connect directly to the experimental device.

Can anyone suggest an existing, simple QBUS device that I could study the
documentation of to figure out what a basic QBUS device needs to have and
to give me some ideas on how to implement one?

I appreciate that if I end up with a device which does not look the same
as some existing QBUS device from a programming point of view, I will
need to come up with suitable device drivers for it too.

Please, no suggestions about drivers and receivers for the QBUS signals,
I will review the many postings on this topic in the list archives.

Peter Coghlan.

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