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I've been playing music on my calculator for a while, and have written some programs to do that. However, whenever I want to make noise, I have to find that little adapter that I keep losing. Plus, only I can hear it. So, I decided to mod my calculator (again) with an internal speaker that can play music.

I took one of those annoying cards that plays music, and ripped out the speaker. Theres a big space in the back of the calculator, behind the screen. After a little Dremeling there was room for this thin speaker. I also drilled a small hole to allow the sound to exit the case. Another bit of Dremeling, and there was a hole for a switch. This way, I can turn it off when I dont want to annoy people. The signal from the link port is put through a Darlington pair (two discrete transistors since I didn't have a single-package Darlington on hand), and to the speaker. It is pretty loud.

I originally had problems with the sound being extremely quiet. I found that my transistor (just one back then) was in backwards (collector and emitter switched.) I flipped it, and it became much louder.

	You can see the wires running up the left
Here is a clearer view of the inside. You can see the transistors on the right.

Download the song (it's in JB2 format)