Swedish engineer creates an accordion from two Commodore 64 computers

In late October, a Swedish software engineer named Linus Åkesson unveiled a playable accordion called the “Commodordion “, which he assembled from two vintage Commodore 64 computers connected with floppy disk bellows glued together. The demonstration of the hack debuted in an 11-minute YouTube video, with Åkesson playing a Scott Joplin ragtime song and detailing the creation of the tool.

Åkesson, himself a versatile musician, can play the Commodordion in real time, just like a real accordion. He plays the melody with his right hand on one C64 keyboard, and controls the chord of the rhythm and bass loop (which he can prerecord with a switch) using his left hand on the other keyboard.

As Åkesson writes in a post on his website, Commodordion took a lot of effort in software engineering and hardware hacking to build. It is based on earlier projects (which he says deliberately led to this) such as Sixtyforgan (C64 with spring reverb and chromatic accordion keymap) and Qwertuoso, a program that allows the famous C64 SID to be played live. sound chip.

So how does Commodordion work? Okesson connected a special power supply, and when he turns on the device, both Commodore 64 machines boot up (no display required). He then downloads into each machine special music software that he wrote from a Commodore Datasette emulator board.

A custom mixer circuit board combines the audio signals from the two devices and measures the input signal from the bellows to control the volume level of the output sound. The bellows, which are made up of many 5.25″flexible discs cut and glued to shape, release air through an orifice when compressed. A microphone mounted just behind this hole converts the noise it hears into a sound shell that manipulates the output sound according to it. The Commodordion itself does not have speakers, instead it outputs electronic sound via a jack.

The Commodordion has one huge drawback, Åkesson writes: ergonomics. While playing, the device puts a strain on his left wrist, arm, and shoulder due to the location of the keys on the instrument’s left side and the fact that his left hand must also bear the weight of the device. “It rather undermines the potential of the Commodordion as a viable musical instrument,” he writes.

However, for a one-of-a-kind homemade hack, the resulting music—especially when Åkesson plays it skillfully—sounds like the perfect soundtrack to a 1980s PC game. This is an 8-bit love letter to a bygone era.