8580 SID - added control over the sustain register, which allows for volume control of each voice. This is probably the trickiest aspect of the SID to get down. Reading about issues with exports from goat tracker put me on the right path with the ADSR generator....
Throwing as much as i can at one voice in an attempt to crash it or cause drop outs. It does neither. Other than the odd click from hopping over pwm extremes. Not bad for 1 voice and 1 wave form.