I had heard of this but your comment sent me searching for more info. I think you might be referring to Visicode.
https://archive.org/details/PersonalComputerWorld1985-07/page/286/mode/2up?q=visicode
https://www.youtube.com/watch?v=xxo1Gs46ti0
https://archive.org/details/PersonalComputerWorld1985-08/page/194/mode/2up?q=visicode
Have a look at the archived pages here : https://al.zerostem.io/%7Eal/teletext/bbc1/1984-09-04-0060.1/
Teletext pages in the 700 range contained the Telesoftware programs
I would imagine Visicode was similar fare although, for reasons I discuss in the article, they're not very easy to find any more.