Wasn't the Microwriter was it perchance?

https://en.wikipedia.org/wiki/Microwriter

I saw that demoed at Notts Micro Computing Club in the early 80s. IIRC a Microwriter was used to drive input for an Acorn Electron.

Yup. There were drivers for both the Electron and the BBC Micro (required the Model B IIRC, Model A didn't have enough spare RAM for the software)