A while ago i picked up a pretty cheap oscilloscope from work. Well, it was new and it was on sale, so who could blame me. Anyway, i finally got a chance to try it out. Of course, i didn't have the correct screwdrivers on me to calibrate it properly. But you still get the idea.
The first picture is of the ipod shuffle playing a 400hz sine tone. The second is of a gameboy playing a c3 on a pulse wave channel. You can really tell which wave shape was used on the gb, can't you... Anyway, i think those curves are due to the cro not being calibrated.