I experimented with the calculators signal output and its ability to create sound. In a good way it is very different from my expectations, most buttons are slowly responsive and build up into a chaos of signals. There is very little different between buttons, it is very clear the signal was design for computer not human recognition. It was also interesting to see the calculator still send signals when turned off.
The signal required some remapping to get the correct values. Onces into processing they were applied to 2 waves that were frequency modulated together. The results are quite good and i feel there is a nice variety and change in the sound.