Subject: Qbus questions
To: None <>
From: maximum entropy <>
List: port-vax
Date: 06/11/2002 03:58:25

I just added a MicroVAX II to my herd of VAXen.  This is my first Qbus
VAX, so I've spent some time browsing the net to see what I could
learn.  I've identified most of the components and have a pretty good
idea of what's going on in there now, but I still have some questions
I'd like to get cleared up.

The BA123 cabinet is missing the two large screws to hold it closed.
It pretty much stays put without them, but I'd like to replace the
screws for extra stability.  Anyone know what size these screws are
supposed to be?

One of the boards is a System Industries 9901-6072-X2.  It has 2
ribbon connectors leading to an external connector.  I'm guessing that
this is a disk interface of some sort.  Is it SCSI?  Does it require a
propritary disk housing of some sort, or can I rig up an adapter to
use standard external SCSI drives?  Is this an MSCP-compatible
interface?  Is it supported by NetBSD?  Ultrix?  VMS?  Can the system
boot from drives attached to this interface?  Anyone have any
documentation for this card?

There are two DHV11-A serial boards.  One of them is in slot 4 (Q/CD)
and the other is in slot 5 (Q/Q).  Is this configuration OK?  From
what I've found, as long as the board only uses the power connections
on slots C and D of the bus, it should be fine.  If it uses anything
else from those slots, then one of these boards must be in the wrong
location.  But I don't know how to tell what connections these boards
are using.

There's an RQDX2 in slot 7, followed by the SI board in slot 8.  From
what I've read, the RQDX2 doesn't provide bus grant continuity, so it
needs to be the last device on the bus.  Either what I read is wrong,
or someone moved boards around and messed up the configuration.  Which
is it?

If anyone has a spare RQDX3 that they would be willing to part with,
I'd love to hear from you.  I have a few VS2000's with RD54 drives
that I would move into the MVII if I could.  I suppose I would also
need a bus grant continuity card, since the RQDX2 that I would be
replacing is quad height, and the RQDX3 is dual height.  Would an
RQDX3 work with the M9058 RQDX Signal Distribution card I currently
have, or would I need an upgrade for that as well?

Thanks for your clues,

entropy -- it's not just a good idea, it's the second law.