Turn A Calculator Into a Musical Instrument

Hello this is Wozn from the band Rooftop Ridicule and tonight I'm going to show you how to turn a Texas Instruments TI-85 Graphics Calculator into a playable musical instrument.

This is a device never even intended to make sound at all.

This is a hack in the category of Circuit Bending, but unlike most circuit-bent projects I intend this to be actually used musically, not just crazy noises, although I love those.

These same principles can be applied not only to other Texas Instruments Calculators, but anything that makes sound and has a little brain that you can change the speed of. Changing the "clockspeed," as it is called, will often also change the pitch. Sometimes when set extremely high or low cool crashes and weird noises will occur, especially in toy keyboards.

Step 1 Hardware: Headphone Jack

For the TI-85 to make sound, assembly language programmers developed techniques involving sending pulses from the linkport. Some programs can even play 4bit samples! The linkport is already a submini headphone jack, so all one would need to get sound out of the thing is an adapter to the standard headphone 1/8" size.

Not good enough. On mine I opened her up and added a headphone jack next to the linkport. I could have replaced the linkport, but I wanted to maintain compatibility with a normal pc-link.

I also added a tiny speaker that connects to the linkport when a switch is flipped, but the speaker is way to quiet without an amplifier so I don't recommend this. Although if you want to do it this is the chip to use: LM386

Comments

[fritsie123]

Can you add a soundfile of just the TI? It's kinda hard to hear through the guitar and drums.

[wozlaser]

yes very soon