vintage computers in active use

[Swift Griggs]

On Thu, 26 May 2016, Bryan C. Everly wrote:
> I did work in UNIX on a Series-1 in the telecom space.  It probably 
> still is in use. 

What kind of Unix did they run? There is almost no information on 
Wikipedia or elsewhere. I'm just curious because I've heard of PC/IX, 
IX/370, and of course I'm *very* famililar with "Ain't Unix" uhhh, I mean 
AIX. :-P I work with it nearly every day. However, I don't know squat 
about the Unix that ran on a Series-1.

-Swift (a guy with a ZOO full of Unix boxes).