16 Aug
2007
16 Aug
'07
3:51 p.m.
It appears I need to take the bus to DEC101:
I have a MicroVax II in the BA23 case. I'd like it to have a SCSI
card. This machine takes qbus cards, I believe.
I recently acquired a CMD CDU-720 card, which appears to be a nice
(and nicely documented) card that supports all kinds of devices, and
speaks MSCP to the Vax. But, it is Unibus.
Am I out of luck here? I gather there are bus converters. Are they
rare? Are they reliable? Should I save this card for the day I
happen upon bigger iron?
Thanks!
--
jht
16 Aug
16 Aug
4:29 p.m.
On 8/16/07, Jason T <silent700 at gmail.com> wrote:
I recently acquired a CMD CDU-720 card, which appears to be a nice
(and nicely documented) card that supports all kinds of devices, and
speaks MSCP to the Vax. But, it is Unibus.
Am I out of luck here? I gather there are bus converters. Are they
rare? Are they reliable? Should I save this card for the day I
happen upon bigger iron?
Most likely you would find a few people willing to trade something
such as a CMD CQD-220/TM for your CMD CDU-720 as from what I can tell
Unibus SCSI controllers are a lot more rare than q-bus SCSI
controllers, at least if availability on eBay is anything similar to
availability elsewhere.
4:31 p.m.
--- Jason T <silent700 at gmail.com> wrote:
It appears I need to take the bus to DEC101:
I have a MicroVax II in the BA23 case. I'd like
it
to have a SCSI
card.
You, me, and everyone else :)
This machine takes qbus cards, I believe.
Correct.
I recently acquired a CMD CDU-720 card, which
appears to be a nice
(and nicely documented) card that supports all kinds
of devices, and
speaks MSCP to the Vax. But, it is Unibus.
Nice score. Very nice score. Err, I mean, totally
useless. Best to give it to me...
Am I out of luck here? I gather there are bus
converters.
Yes, there are - going both ways too. The PDP-11/84,
for instance, is a short qbus card cage (for CPU and
memory) with a Qbus to Unibus adapter, and all Unibus
I/O. I don't know if such a device would work on a Vax
though, but it should. There are Unibus Vaxen.
Are they
rare?
Not as rare as a Unibus SCSI card.
Are they reliable?
Should be, as long as they are cabled up properly.
Adding a seperate Unibus crate to an existing Unibus
system was quite common, and Unibus will work over
several feet.
Should I save this card
for the day I
happen upon bigger iron?
Yes.
-Ian
6338
days inactive
6338
days old
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