For awhile now I've wanted to make a synthesizer on my calculator using the I/O cable (unfortunately I don't have one of these; maybe I'll get 1 soon). The only thing I'm worried about is this: if I attach a small speaker, maybe even (an) earbud(s) to the I/O cable, are there risks of damaging my calculator involved? I'm pretty experienced with electronics/circuitry; I've been building circuits since I was 7 or 8 (about 8-10 years ago). Some of my best circuit designs have been of robots that can not only navigate using light/infrared, but that can also climb stairs (they can't go downstairs, ironically). I never built the mechanics for these bots, but I designed the circuitry, and I know that the sensor theory and transistor configurations are sound. I also know that I'm getting off topic, SO: Anyone know anything about the internal goings-on of the TI-84?