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This applet plays a variety of cool, old-time-videogame-like sounds. To start, click the Sound on checkbox and then select one of the presets.

The intent is to loosely emulate the pitch envelopes from the Acorn BBC microcomputer, but most people haven't heard of that nowadays (still not sure why I was given one for work, especially in the US). So here is a brief description of how envelopes work.

The pitch changes in steps; the length of time a step takes is adjustable using the Step Length slider. At each step, the pitch changes by the value specified in the Step Size 1 slider. The starting pitch is 89, which is middle C, and the pitch can go as low as 0 (about 72 Hz) to 255 (about 2890 Hz), and it wraps around if it is incremented above 255 or below 0. A pitch difference of 48 equals an octave.

After some number of steps (specified by the Step Count 1 slider), we finish section 1 and start section 2, where the Step Size 2 and Step Count 2 sliders control the size and number of steps. Then we go to section 3, and when that is finished we go back to section 1. If the step count for a specific section is 0, then we just skip that section.

Just play around with the sliders and you'll figure it out.

The sound is output using a pulse waveform. The Pulse Width slider controls the pulse width.

2/7/09: v1.1 fixed to work on java 2.

The source.

More applets.