On 2/16/19 7:55 AM, Bill Gunshannon via cctalk wrote:
So, I used SIMH to do an install of a complete OS on
an RA81 disk. I would like to move this to a real disk
and try it on a real PDP-11. Is there a way to do this
using dd on a BSD machine? I tried but it created a
non bootable system. Well, actually, it starts to boot
but then fails very early in the startup process. I used
"dd if=filename of=raw-device bs=1024". Could it be that
the block size needs to be something else?
I know that VTServer and PDPGUI can move disk images but
it would take a week at 9600 baud and I think very little
likelihood of it ever completing successfully.
bill
As long as the media is presented as "Error Free", you should be able to
to change the block size. Since a RA81 (MSCP) remaps error blocks
automatically and invisibly, it should work. Is the media type the same
on SIMH and Real PDP11? If all else fails try bs=512.
For drives that have OS visible media defects, you should make sure the
block size matches the same on the media and also use the option
"conv=noerror,sync". Otherwise dd will actually reorders the blocks(!),
good first then zero fill the ones it cannot read.
Jerry
