I was able to get part way some years ago by demodulating the bitstream with gnuradio and then making small changes (like replacing one note with the next higher one) and noting the differences. So that is one possible, but probably too inefficient way.
I never got close to finishing or publishing anything. Awesome to see this released and I'll have to play with it!
No, not beyond what I already put in the twitter thread. I wanted to wait until I had some cool distributed software running on it too, but then I ran into trouble with the plan 9 wifi drivers for the rpi being unstable and so I'm still working on fixing that. It does serve as a great test bed for that purpose too, as with 8 nodes I can get much more reliable data about how often the driver gets stuck
Wanted to reply to you directly also to increase the chance you see this because I think I had exactly the same intrusive thought as you, and actually built such a cluster recently. Would love to hear what you think: https://x.com/andreer/status/2007509694374691230/photo/1
Instead of having to use lots of dongles and usb ethernet, I just wired them all up using brass rods, a small 5V power supply in the base, and boot them over WiFi (just the kernel and wifi config on the sd card).
Raspberry pi's are cheap, easily available, and there is an absolutely massive trove of information about them on the internet. And the scale means that the linux implementation is very stable and "just works" to a degree that is extremely hard for other SBCs to match.
Sure, VMs are the logical choice, but not everything has to be logical. Real hardware does feel more real :-)