(Note: Yes, I know a 3B2 is not related at all to a 3B1! But I figure if you're interested in one, you're probably interested in the other.)<p>As late as 2002, at AT&T Easylink Services we were still using 3B2s to process email and email-to-fax on a private X.25 network; the beginnings of a 3B2 emulation-on-Sun-hardware project was in the works; I don't know if it ever went anywhere.<p>Some interesting documentation I wrote here: <a href="https://3e.org/private/gms/" rel="nofollow">https://3e.org/private/gms/</a>
For those who didn't know what this was and (wrongly) thought it was some sort of IBM-compatible: <a href="https://en.wikipedia.org/wiki/AT%26T_UNIX_PC" rel="nofollow">https://en.wikipedia.org/wiki/AT%26T_UNIX_PC</a>
Being Australian, I don't know much about the company other then it's a popular telecom provider in North America so it's interesting to see that they had their hands in workstations at some point.
The 3B1 was one of the few uses of the 68010, which was basically a 68000 with a few bug fixes and, importantly, support for virtual memory. Combined with a separate MMU, this allowed you to run Unix.
Another neat aspect of this machine was the hype around it at the time. AT&T took out ads in most magazines and pundits thought it would overtake the IBM PC because it ran UNIX and had some great software, including the first version of Microsoft Word (which was originally written for UNIX, specifically Microsoft's Xenix).
Back in the early 90's, I had a friend with one of these. It was a neat machine. I remember an unusual windowing system on it ("MGR", I think?) We were starting to get into PC unix clones - first Coherent, then Linux (SLS distro?) - around the same time.
As an intern during college I remember installing the OS on a 3B1 at one of my first summer jobs. So many floppy diskettes. Don't remember much more about it other than it seemed pretty primitive compared to the Sun workstations that were prevalent around the office.