Accordions are available many shapes. Some have a bit of piano keyboard whereas others have a grid of black and white buttons set roughly within the form of a parallelogram. I’ve been fascinated by this “chromatic-button” format for a very long time. I spotted that the buttons are staggered similar to the keys on a typewriter, and this perception someway become a blurry imaginative and prescient of an accordion constructed from a pair of Nineteen Eighties residence computer systems—these machines usually sported a built-in keyboard in a case large enough to kind the 2 ends of an accordion. The concept was intriguing—however would it not actually work?
I’m an skilled
Commodore 64 programmer, so it was an apparent alternative for me to make use of that machine for the accordion ends. As a retrocomputing fanatic, I needed to make use of classic C64s with minimal modifications fairly than, say, gutting the pc instances and placing trendy gear inside.
As for what would go between the ends, accordion bellows are a set of semi-rigid sheets, usually rectangular with a gap within the center. The sheets are hooked up to one another alternating between the interior and outer edges. One other flash of perception: The bellows might be produced from a stack of 5.25-inch floppy disks.
Now I had a number of compelling concepts that appeared to work collectively. I secured a big amount of dangerous floppies from a fellow C64 fanatic. After which, armed with all the things I wanted and keen to start out, I used to be promptly distracted by different tasks.
A few of these tasks concerned methods of enjoying music stay on C64 computer systems. The concept to mannequin a musical keyboard format after the chromatic-button accordion grew to become a standalone C64 program launched to the general public referred to as
Qwertuoso.
Along with two classic Commodore 64s [left], the Commodordion has a microphone for detecting air circulate by means of the bellows, and buttons for turning on the facility and controlling a tape-deck emulator [top right]. The bellows are produced from tape and 5.25-inch floppy disks [middle right]. One supporting board incorporates a microcontroller to measure the airflow and blend the audio indicators, a second shops the accordion software program and emulates a cassette participant, and a 3rd acts as an influence hub.James Provost
That might nicely have been the top of it, however I had all these disks on my arms, so I made a decision to go forward and attempt to craft a bellows in spite of everything. The physique of a floppy disk is produced from a folded sheet of plastic, which I unfolded to kind the bellow’s segments. However I had underestimated the issue of air leakage. Whereas the floppy-disk materials is hermetic, the seams aren’t. In the long run I needed to patch the entire thing up with a number of layers of tape to get the air to remain inside.
An actual accordion makes use of the bellows to push air over reeds to make them vibrate. How briskly the bellows is pumped determines the accordion’s loudness. So I wanted a option to sense how briskly air was being squeezed out of my floppy-disk bellows as I performed.
This was trickier than I had anticipated. I went by means of a number of failed designs together with one impressed by the
“scorching wire” sensors utilized in gasoline injection techniques. Then sooner or later, I used to be watching a video and I spotted that an individual within the video was shouting so as to overcome noise attributable to wind hitting his microphone. That was the breakthrough I wanted! The answer turned out to be a small microphone, mounted at an angle simply outdoors a small gap within the bellows.
Air flowing into or out of the opening passes over the microphone, and the ensuing turbulence turns into audio noise. The depth of the noise is measured, in my case by an
ATmega8 microcontroller, and is used to find out the output quantity of the instrument.
The bellows is hooked up to a easy body constructed from wooden and acrylic, which additionally holds the C64s in addition to three boards with supporting electronics. One in all these is an influence hub that takes in 5 and 12 volts of DC electrical energy from two household-power adapters and distributes it to the varied elements. For ergonomic causes, fairly than utilizing the traditional socket on the C64s right-hand sides, I fed energy into the C64s by wires handed by means of the case and instantly soldered to the motherboards.
The Commodordion is performed by utilizing the keys on the Commodore 64s and squeezing the bellows between. Air transferring by means of the bellows creates a loud or gentle noise relying on how exhausting the bellows are squeezed. A microcontroller working an envelope-following program controls a multiplexing digital-to-audio converter that units the ultimate quantity of the mixed sound from the C64s.
James Provost
A second board emulates Commodore’s datasette tape recorder. This shops the Qwertuoso program. As soon as the C64s are turned on, a keyboard shortcut constructed into the unique OS directs the pc to load from tape. The ultimate board incorporates the microcontroller monitoring the bellows’ microphone and mixers that mix the analog sound generated by every C64s
6581 SID audio chip and adjusts the amount as per the bellows air sensor. The audio sign is then handed to an exterior amplified loudspeaker to supply sound.
With a view to attain the keys on the left-hand facet when the bellows is prolonged, my hand must bend fairly far across the fringe of what I dubbed
the Commodordion. This places a number of pressure on the hand, wrist, and arm. Partly for that reason, I developed a sequencer for the left-hand-side machine, whereby I can program a easy beat or sample and have it repeat mechanically. With this, I solely should press keys on the left-hand facet often, to modify chords.
The Commodordion
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As a musician, I’ve to take ergonomics significantly. While you study to play a chunk of music, you follow the identical motions time and again for hours. If these motions trigger pressure you may simply spoil your physique. So, sadly, I’ve to limit myself to enjoying the Commodordion solely often, and solely play quite simple components with the left hand.
Then again, the right-hand facet feels completely positive, and that’s very encouraging: I’ll use that as a place to begin as I proceed to discover the design area of devices produced from outdated computer systems. In that mild, the Commodordion wasn’t the ultimate purpose in spite of everything, however an necessary piece of scaffolding for my subsequent artistic endeavor.
