ptracker, a 1-bit tracker for the Commodore PET

I think I forgot to post this here, but the stuff I was doing on 1-bit music on the 6502 a while back turned into a fully-fledged 3½-track tracker for it: https://cowlark.com/ptracker/ It's... crunchy. There's only just barely enough CPU for it to work, meaning there isn't even a progress indicator while playing, and I'm pretty sure that it's overrunning at times but luckily you can't tell given the sound quality!

So far I've done covers of Jugi's Onward Ride: https://www.youtube.com/watch?v=iqWJeM2MKt4 (as made famous by the DOPE demo)
...and Darude's Sandstorm: https://www.youtube.com/watch?v=qeUOBw00vq4 (as made famous by... everyone?)

Both were tracked using ptracker itself. (I'll also point out that tracking a piece of music that is essentially a single phrase repeated over and over for three minutes with minor variations has melted my brain.)

It uses the CB2 FIFO on the PET's 6522 to do most of the heavy lifting so I suspect it's doubtful if the engine would port easily to other 6502 systems (unless they also use CB2 for sound; are there any?)...