Freespin is a Commodore 1541 demo, released in 2021.
It runs on the Commodore floppy drive. It is is the first demo on this device.
You can watch it (and some introduction/explanation of the wiring and bootstrapping) on YouTube:
Freespin generates sound/music using the floppy drive mechanic (in particular, the stepper
motor responsible for moving the head to the right track). Video is generated through
the serial bus. The video signal needs to be connected to the drive’s two output lines
as shown in the following diagram:
If needed, the 100 Ω resistor can be harvested out of the C64. (E.g. the not strictly
necessary R14 AUD IN pulldown.) As such, this demo runs on stock C64 hardware and doesn’t
need any extra components.
The demo is 3 minutes 40 seconds long, and displays 16 effects.
The links below point to more in-depth blog posts about freespin.