Warner Losh writes:
That tape image is has 3 files in it:
The first consists of a bunch of 1024-byte records followed by a
single 512-byte record. It may be a boot loader.
The second is a file system dump. I haven't attempted to examine
its contents yet.
The third is a tar of /usr, with absolute pathnames for all files
in it.
The tar archive truncates abruptly in the middle of a Franz Lisp
manual source file, which it is trying to extract somewhere under
/usr/tape1/.
Some of the directories in the tar archive have modification times
in 1982, but all of the files in the tar archive are 1981 or earlier.
If you ignore /usr/tape1/* and look only at the earlier files in the
tar archive, it appears it might be a legitimate copy of 4.1BSD as
of Aug 31, 1981. In particular, there is a large cluster of files
with modification times of 7/9/1981, and fewer than 25 files newer
than that. The newest file (excluding the /usr/tape1 material)
is 8/31/1981.