[Simh] Extracting SimH Tapes on Linux

[Edward Berry]

Out of curiosity, what is a "tape dump"?

"dump is a Unix program used to back up file systems. It operates on blocks, below filesystem abstractions such as files and directories. Dump can back up a file system to a tape or another disk. It is often used across a network by piping its output through bzip2 then SSH.
A dump utility first appeared in Version 6 AT&T UNIX.[1]" - wikipedia

Say simh running on unix dumps the image of one of its (simulated) disks to a (simulated) tape.
the tape image is then saved (via unix commands) for future restoration of the disk.
(this wouldn't make much sense, because you could just save the disk image)

Or some real (not simulated) system, say a vax, dumps the image of one of its disks to a real exabyte tape. A special program is used to "enblock" the dump so it can be read by simh. The dump file is then extracted to unix using "dd" if it is a raw dump or unix version of "backup" if the tape has a filesystem. Now instead of mounting that as a tape image (or disk image?) on simulated vax, you want to get at the files from unix?

Ed

On 11/29/2014 09:32 AM, Stephen Merrony wrote:
> Can someone remind me of the magical incantation to extract a tape dump in SimH format to its constituent files on Linux?
>
> I know I've done this in the past, but I'm damned if I can remember how...
>
> Thanks,
>
> --
> /Stephen Merrony
> http://www.stephenmerrony.co.uk//dg
>
>
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