Small library to send data over sound. Basically: send data even to air-gapped devices.

https://github.com/ggerganov/ggwave

GitHub - ggerganov/ggwave: Tiny data-over-sound library

Tiny data-over-sound library. Contribute to ggerganov/ggwave development by creating an account on GitHub.

GitHub
@mpe Back in the early 1980's, I had a chance to use the Coleco Adam computer, and recall it stored "applications" on cassette tapes, which you could also "play" on a regular cassette deck for amusement ! Your tool reminds me of that.
https://en.wikipedia.org/wiki/Coleco_Adam
Coleco Adam - Wikipedia