On Sat, Oct 19, 2019 at 02:23:46PM -0400, Nigel Johnson via cctalk wrote: > Judging by the year, it was probably a teletext terminal. [...]
It's not Teletext, unless that word means something different on the other side of the Pond. Teletext was basically a text system (the hint's in the name) with graphics (and indeed colour) being a weird hack that gave it a particular appearance, especially in typical implementations which used the SAA5050 character generator chip. The palette and colour fringing suggest Apple II to me.