Random musing: VCB02 on VAX-11/750

Josh Dersch derschjo at gmail.com
Sat May 27 20:15:13 CDT 2017

So I had a random thought in the wee hours this morning and I leave it 
to you, the cctalk braintrust, to tell me exactly how stupid this idea is:

I have a VAX-11/750, an Able QNiverter (UNIBUS->Qbus adapter), a 22-bit 
Qbus backplane, and a VCB02 (QDSS) 4-bit graphics boardset.

Theory: With an appropriately modified NetBSD driver for the VCB02, such 
that it provides only 18-bit addresses to the VCB02's DMA engine, I can 
get X running on the VCB02 on the 11/750.

That is, the configuration is: 11/750->Unibus->QNiverter->Qbus->VCB02.

Obviously the console functionality of the VCB02 won't work since that 
requires support on the VAX side of things that won't be present, but I 
think everything else should work.  I've browsed the technical manual 
and I don't see anything that should get in the way, I'll just need to 
hack up the driver appropriately.

But this is something that randomly popped into my head (I was inspired 
by a research paper, "A VAX Based Data Acquisition Computer System at 
the Nuclear Structure Research Laboratory" wherein a Matrox QRGB Qbus 
graphics board was lashed to an 11/750 in a similar manner...

What say you all?

- Josh

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