PDP-11 disk image question

Paul Koning paulkoning at comcast.net
Mon Feb 18 08:16:54 CST 2019

> On Feb 17, 2019, at 2:32 PM, Paul Koning via cctalk <cctalk at classiccmp.org> wrote:
>> On Feb 16, 2019, at 1:04 PM, Bill Gunshannon via cctalk <cctalk at classiccmp.org> wrote:
>> ...
>> First, my hardware.  I  have a PDP-11/93 with a CMD SCSI Module and
>> a BA350 with 6 2GB hard drives.  The Module is set up to present RA81
>> disks and the first 3 disks have 4 partitions each which should work
>> out to 12 RA81 disks. (But that last part is unimportant right now!)
> A real RA81 has 891072 blocks, i.e., it's 445 MB.  If your partitions are indeed 1/4th of a 2 GB disk they may be just over 512 MB.  If so, your RA81 image is not valid for those partitions.
> Try shrinking the partitions to be the actual RA81 size, or slightly larger.

Alternatively, in SIMH define your disk to match the size of the actual device, and transfer your system to that disk.  It should be just a matter of copying everything (which in V9.0 or later is easily done with the BACKUP command) and you then probably have to use the HOOK utility to write the boot block.


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