Pictures on Audio Tape - No Joke!
Comments disabled becuase I'm sick of getting a bazillion comments every day on ancient videos of mine that I don't care about any more.
Some old 8-bit home computers were able to load and save data onto cassettes, and some of that data was pictures. I thought if they could be recorded onto tape digitally, surely they can be recorded onto tape in analogue. Well, I found a program that can do that, it encodes the picture to an analogue audio signal, and then it can be recorded onto any sound recorder. If the sound is analysed on a spectrogram, you will see the orginal picture.
I looked into this a bit, and from what I could find out, this method was actually used to transmit pictures though radio back in the 60's, some rock bands even put them into their songs and the odd one or two have appeared here and here. I think it's called slow scan TV spectrograph or forier or something like that. I do already know you can could record 32-line Baird TV transmissions onto audio tape as they fit within the audio bandwidth, they used phonograph records to record them when it was used in the 30's, but recording and sending still pictures encoded to audio has a lot more detail.