Have a look at the archived pages here : https://al.zerostem.io/~al/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.

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

That reminds me. They did used to broadcast software over teletext over TV https://teletext.mb21.co.uk/gallery/ceefax/telesoftware/