[TUHS] AT&T 3B1 - Emulation available

Brad Spencer brad at anduin.eldar.org
Fri Feb 19 04:07:55 AEST 2021


arnold at skeeve.com writes:

> Ed Carp <erc at pobox.com> wrote:
>
>> Wasn't the 3B1 the same thing as the 7300?
>
> There were differences in the amounts of memory and size of disk. The 3B1
> had room for a larger disk and thus its case was shaped differently.
> In terms of other hardware and the software, they were the same.
>
> Arnold


Hmm..  think I used one of those 7300, aka Unix PC systems when I was an
undergrad a long time ago.  It looked like images I find on the Net in
any case, but it was a long time ago.  Whatever it was that we had, I
remember that the floppy drive was 5.25 inch and used 512 byte sectors.
I had a Radio Shack Color Computer 3 at the time and the disk controller
on that would read a 512 double density byte sector disk just fine.  I
had gotten pretty good at reading foreign disks on the CC3 and I put a
copy of /bin/sh onto the floppy on the Unix PC and then used the CC3 to
adjust the ownership and mode to make the copy of the sh binary setuid
root.  Since the Unix PC would allow anyone to mount the floppy (at
least on the one we had) and since they didn't restrict setuid for the
mounted floppy I ended up with a root shell.  Fun times...  used it for
some class work instead of the PDP11/44 running BSD that we also had at
the university.




-- 
Brad Spencer - brad at anduin.eldar.org - KC8VKS - http://anduin.eldar.org


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