On Mon, Aug 22, 2022 at 11:55 PM Lars Brinkhoff <lars@nocrew.org> wrote:
Warner Losh wrote:
> So 60011 is OFS_MAGIC and 60012 is NFS_MAGIC. Both of these are
> variants on UFS, but really old. And given they are at different
> offsets, you'll likely need to reverse engineer the offsets used for
> the platform's dinode.

So anyway, it seems my best bet would be getting an old "restore" and
hack it till it runs.

Part of the problem is that there are hundreds of these images, so it
would be a lot of work to examine them individually in emulated systems.
A good first start to examine the content would be to just list the file
names.

For V7 tapes, you can run the V7 binaries using apout with very little effort.
This is a user-level emulation of a pdp-11 with the system calls for v5, v6, v7 and
some of the BSDs. It's in the tuhs archives under Distributions/Research/Dennis_v1/unix72/tools/apout.
I used it to extract files from V7 automatically that I used in the 2.11 back-patching-to-the-original-tapes
script I wrote.
 
> Without more specific data it's hard to know if there's an extant
> binary that can be run in emulation to read these tapes.

The tapes are from MIT's "Tapes of Tech Square" collection.  Likely
candidates include PDP-11 V7, 4.x BSD on VAX, and Sun workstations.  I
suppose the latter would use the big endian format.

Very cool. I suspect if you want one tool for them all, you'll need to take restore
and teach it to cope with multiple endians and word sizes... It's likely not a huge
effort, but the restor code from V7 makes use of a lot of type-punning...
 
There are also many variations of the tar and cpio formats, but I'm on
firmer ground there.

Warner