So I got a cheap Pi Pico as the postage and packaging were more expensive than adding in a Pi Pico to exceed the minimum free P&P limit. It’s about a 2 MB flash drive with a dual computing core and some simple GPIO. It looks like it can do about 500k sample/s ADC over 3 channels at 12 bits, so some audio project seems like a good idea to try.
It has some Amiga “copper” style coprocessors for IO too, so making a video raster scan is likely easy too. It does have enough power to simulate an 8-bit core with a spare CPU left for other purposes. At 133 Mhz that’s quite an efficient bit of silicon area. A 1980’s super-computer with slightly less vector parallelism and a bigger (smaller) storage media. Bargain!