Re: I actually used one for a University assignment

Looks a lot like the ones they had in Durham. I think they were as pictured here.

They were used to teach machine code to 1st year undergraduates in 1979/80 at least. No big deal for those of us who'd already programmed HP calculators. At the time they seemed kind of quaint, although they were presumably quite new. It was just that things were moving pretty quickly.

They also had Acorn Atom machines about, which were much more interesting than these things at the time.