The Commodordion > Two C64s Plus Some Floppy Disks Equals One Instrument
Linus Akesson · IEEE Spectrum · 2023
Describes the special features, components, and operations of the Commodordion. It is played by using the keys on the Commodore 64s and squeezing the bellows between. Air moving through the bellows creates a loud or soft noise depending on how hard the bellows are squeezed. A microcontroller running an envelope-following program controls a multiplying digital-to-audio converter that sets the final volume of the combined sound from the C64s.