Carlc27843 has written for PICO-8 an Amstrad CPC AY-3-8910 sound chip emulator using undocumented 5512Hz 8-bit mono PCM channel, to compose or convert Amstrad CPC music by Dave Rogers.

And I just tumbled on his two other creations : a remake de Nebulus and a demo about the game Cauldron on Pico-8 of course. Hit the links so you will able to see a video of the game and the demo.