Published by KermMartian on November 30, 2011 at 12:43:21 AM CST | Discuss this article (19)

Continuing to stretch the boundaries of graphing calculator hacking, hardware, and software, Christopher Mitchell and Cemetech Labs are proud to present music played on a floppy drive... controlled by a calculator. Inspired by other projects such as the Star Wars Imperial March played on two floppy drives and Bach's Toccata and Fugue in D Minor, BWV 565 on four floppy drives, I hoped to implement this concept on a much more limited control device: a TI-83+ graphing calculator. While microcontrollers such as those used in the projects above have dozens of GPIO pins for interfacing with external hardware, the TI-83+ graphing calculator has only two I/O lines, both bidirectional. I did a bit of research on controlling floppy drives, and discovered that if I held pin 16 (Motor Enable) and pin 12 (Drive Select) of the floppy drive low, I need only pulse the Direction In and Step pins (18 and 20) to control the floppy drive's read/write head stepper motor. I put together the circuit, discovering in the process that previous projects had incorrectly identified pins 10 and 14 as the necessary lines to hold low, and then modified my mobileTunes 3.1 media player for calculators to output the necessary control signals to modulate the floppy drive's motor. Other than the floppy drive, the calculator, and a breadboard for making interconnects, the only hardware used is a standard 5/12V power supply for the floppy drive. Enjoy the results as demonstrated by Coldplay's "Clocks" in the video below!

More Information
Floppy Drive Music with a Calculator project page
Floppy Drive Music from a TI-83+ demo video



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