Hardware

Watch Freespin, the Insane 1541 Disk Drive Demo

ByChristian Cawley July 9, 2021

Last Updated on July 9, 2021

You’ve probably seen a disk drive (or army of drives) used to make music. But have you seen a single unconnected Commodore 64 1541 disk drive demo like this before?To be honest, you probably won’t believe your eyes. The process involved sending a program to the 1541 drive, then disconnnecting the Commodore 64, and rewiring the cable to connect to a monitor.

Titled Freespin, this 3.40 minute long demo displays 16 effects and uses the floppy drive’s stepper motor. This means that audio is through a single channel, with a single rectangle waveform. Volume adjustments and tremolo are not possible, with limited memory – about 256 bytes for around 10 seconds. This results in breaks in loading that last around 0.14 seconds every so often.

Matthias Kramm explains on his website:

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.

A diagram is provided, which may inspire similar projects. Kramm’s blog is full of useful information that can help anyone trying to replicate the project and produce more amazing 1541 disk drive demo “chiptunes”.

The idea that an unconnected disk drive could play music in this way is simply mind blowing.