The dutch national broadcasting service had a program around 1980 where BASICODE (https://en.wikipedia.org/wiki/BASICODE https://en.wikipedia.org/wiki/BASICODE)

The dutch national broadcasting service had a program around 1980 where BASICODE (https://en.wikipedia.org/wiki/BASICODE https://en.wikipedia.org/wiki/BASICODE) for homecomputers was transmitted. Lots of home computers (ZX Spectrum, C64 etc) had audio I/O for storage on cassette tapes.