Re: Burroughs/Unisys...
I remember those. It was made by Convergent Technologies.
I worked for Unisys in Birmingham in 87/88 and had a few visits to the Milton Keynes training centre. I did work on these.
After that I worked for Bull Information Systems in London and discovered to my horror they rebadged it as well, called it a B20 I think and renamed the operating system to Starsys.
The one I had on my desk had just about every available module and was about three foot long.
https://en.wikipedia.org/wiki/Convergent_Technologies_Operating_System
It was actually quite a clever design. Pity my manuals had been translated from American English to French and then to proper(ish) English. Made for some interesting reading.