Impressed that this short bit of assembler code was responsible for the chime I hear when I start up my Macbook Pro, I set out to convert it to Javascript. Well, a few hours into this project when I start hearing the first (still quite off) results did I learn that actually the current chime is very very different from the original Mac chime: http://www.youtube.com/watch?v=GSuVacw8I-o

What I don't quite get is that the asm code seems to start with a sharp square wave that smoothens off as time passes, but in that video the first sound already sounds very smooth in the beginning.

Read http://www.mactech.com/articles/develop/issue_16/034-038_Qui..., especially the part that says:

   "Square wave sounds. Unknown to most, the square wave synthesizer never produced
    true square waves. It was more like a modified sine wave. This has been corrected.
    As a result you'll notice that the Simple Beep sounds different. It can now be
    heard as it was originally designed to sound."