Sounds very much like BASICODE[1] which was used to broadcast e.g. tax return software on national public radio in the Netherlands back in the 1980's [1] https

Sounds very much like BASICODE[1] which was used to broadcast e.g. tax return software on national public radio in the Netherlands back in the 1980's [1] https://en.wikipedia.org/wiki/BASICODE https://en.wikipedia.org/wiki/BASICODE