SIDcog is a project from Johannes Ahlebrand. He made a hardware simulation of the Commodore SID music chip inside a Propeller micro controller. Some of the features are: 31kHz sample rate. 16 bit resolution. Full filter and envelope support. All 4 waveform types and combined waveform. Ring modulation and oscillator synchronization. On the Youtube channel from Johannes you can see several demonstrations of the SIDcog.

Sidcog information and download.