out-of-mainstream minis

[Johnny Billquist]

On 2015-07-04 01:54, mark at markesystems.com wrote:
> In the late 80’s, I bought from a surplus/junk shop a (by then somewhat obsolete) Unix computer, branded UniSys, I think.  It had 10 serial ports; one was the primary console, one was intended for a printer, and the other 8 were regular user TTYs.  The processor was a 68000 (not 010, 020, or anything else), I don’t remember how much memory, and it had an integral full-height hard drive as well (60 mB, maybe?).
>
> When I say Unix, I mean real System-7 Unix – not Linux or any other *nix.  I thought it was really a pretty neat system – 8 (or 9) users and a printer, just perfect for a small office – or my apartment at the time, which had a terminal or two in every room.  I learned how to program in Unix on that machine, since it matched exactly the System 7 manuals I had. Sadly, time moved on, I got married, and got rid of a bunch of “useless junk”, like that computer.
>
> Recently, I’ve been reminiscing and poking around some on the Web to try to find information about it, but it seems to have vanished completely with nary a ripple.  Has anyone else stumbled across this unit, or at least have any knowledge of it?  It was a black case, about the size of a standard IBM-PC, with ten serial ports on the back and not much else.  I’d sure be interested to know where I might locate data about that unit, or (gasp!) possibly even an existing one...

I find it hard to believe it was a plain 68K in there. That CPU have 
some serious issues that makes it close to impossible to implement 
virtual memory or proper usermode protection.
(Yes, it can be done, but the amount of hardware required means most did 
not. I think SUN did it with their own MMU, and an extra CPU in there. 
Trying to remember who else - I seem to remember one other company who 
actually used a plain 68K, and it was not Unisys.)

Essentially, the 68010 is pretty much the minimum of processor needed to 
make a sane system to run Unix on.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol