The recent reference to the Dennis’s comments on ATT chip production had me feeling nostalgic to the 3B line of computers.  In the late 80’s I was in charge of all the UNIX systems (among other things) at the state university system in New Jersey.   As a result we got a lot of this hardware gifted to us.    The 3B5 and 3B2s were pretty doggy compared with the stuff on the market then.   The best thing I could say about the 3B5 is that it stood up well to having many gallons of water dumped on it (that’s another story, Rutgers had the computer center under a seven story building and it still had a leaky roof).    The 3B20 was another thing.   It was a work of telephone company art.    You knew this when it came to power it down where you turned a knob inside the rack and held a button down until it clicked off.    This is pretty akin to how you’d do things on classic phone equipment (for instance, the same procedure is used to loopback the old 303 “broadband” 50K modems that the Arpanet/Milnet was built out of).    Of course, the 3B20 was built as phone equipment.    It just got sort of “recycled” as a GP computer.