I had the video for this uploaded but not the cart, anyway it's here now. Some of these routines (but more optimized) ended up in Ad Astra.
A demoscene demo by Ate Bit for the Pico-8 virtual console.
Release date : 13/08/2016
Code & music : 4mat
Graphics : ilkke
Please leave audio enabled, demo uses the STAT variables to maintain timing and scenes won't continue otherwise.
Due to the way I merged some _update and _draw code together the demo may go out of sync if you don't have the window focused. This may only affect watching it in pico-8 rather than the web version however.
4-beat is a little proof-of-concept drum machine. I was trying out some beat syncing ideas by writing into the sfx data while the music player is running. No features, only 2 speeds :), but more in sync that my previous version.
Some extra controls are:
X+Up/Down = Change tempo. (only fast and slow)
X+Left/Right = Change shuffle rhythm.
Oh, you can only play 4 drum sounds on each beat obviously. :)