Technical SID documentation

The following is a transcription of Appendix O in the Commodore 64 Programmer's Reference Guide done by Asger Alstrup. HTML version and pictures by Andreas Varga (


Software stuff
Hardware stuff

This is an examination of the SID waveforms that was developed and conceived by Asger Alstrup. HTML version by Andreas Varga.

Description of the:

Triangle Waveform
Noise Waveform

Here you'll find additional technical info, but be careful, some of this information is know to be wrong !!!

The SID patent document

Here's a bit of SID history. An article published in the Swedish computer magazine called "DatorMagazin" in 1987. It covers the creation of the SID chip. This article was sent to me by King Fisher of Triad.

The creation of the SID chip

To learn more about the SID and its creator read this interview with Bob Yannes. It contains a full description of the SID's inner workings.

Interview with Bob Yannes

Last updated: Apr 3 1997