Both of the 2bsd tapes you found are from the
days when Berkeley just sent patches to the 7th Edition out.
The 2.8BSD tape was the first one to have a kernel that was
bootable from the tape. The 2BSD tapes originally had 2 files
on them. The first one was a binary copy of tar that ran on
V7. The second was a tarball of all the rest. As you
discovered, they shipped with a label like:
Second Berkeley Software Tape
May 10, 1979 TAR 800BPI
%dd if=/dev/mt0 bs=1b skip=1 of=tar
%chmod 755 tar
% tar x
10000 blocks
but the 2bsd.tar.gz file has just the second file.
The spensor_2bsd.tar.gz has a tar binary in it:
tar tvf spencer_2bsd.tar.gz | head
-rw-r--r-- 0 0 0 24688 Feb 17 1980 tar
-rw-r--r-- 0 0 10 3687 Feb 17 1980 tar.1
-rw-r--r-- 0 0 10 456 Feb 17 1980
tar.ms
if you are looking for that pre-built. If you are looking
to create a tape with tar on it to extract other tar tapes,
you'd need to use a variation on the
maketape.pl
with a block size of 1 so the above dd will work on the
target system...