PDP-11 disk image question

Glen Slick glen.slick at gmail.com
Mon Feb 18 21:59:48 CST 2019

On Mon, Feb 18, 2019 at 5:18 PM Bill Gunshannon via cctalk
<cctalk at classiccmp.org> wrote:
> Well, all I really have are CQD module which does MSCP and TMSCP
> over SCSI.

Do you have any SCSI tape drives? I have successfully installed RSTS/E
10.1 from install tapes on real PDP-11 hardware using an Exabyte
EXB-8200 8mm tape drive attached to a CMD CQD-220/TM. The target hard
drive for the installation was also attached to the CMD CQD-220/TM.
That is always one route you could try.

My guess is that the other posts about disk sizes being different is
likely the issue. When I want to use a physical drive attached to
Q-Bus SCSI controller to be the target of a copying a simulated disk,
I usually try to verify that the MSCP block count for the physical
drive is actually what I expect it to be.

If I can attach the Q-Bus SCSI controller and drive to a MicroVAX
system I can boot VMS and mount /foreign the drive and show dev /full
the drive to get the block count. Or if the the Q-Bus SCSI controller
and drive are attached to an 11/53, /73, /83 (or /93 if I had one of
those) I can boot the 2.11BSD install tape and run the standalone
disklabel program to display the reported MSCP geometry of the drive.
The must be several other ways to display the MSCP reported geometry
of a drive, those are just two that I have used myself in the past.

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