First I have to thank x1541 and everybody who contributed for this awesome project known as SwinSID you guys rocks!
However I have found some weird shortcomings of the device, which I think could been easily addressed:
- support for paddles -- the atmega88 has 2 unused ADC channel which should be used for at least for potentiometer input (lot of musicians use potentiometers connected to paddles to modify sound - mouse support would also be nice)
- PAL/NTSC (other?) selection -- sampling the computer's clock after reset could be used to set the output's base frequency (the CBM/B machines also use SID at ~2MHZ!!)
- may be some support for ext_audio_in(?) -- ok, I know it would be more different, and more difficult, but rearranging the pins may free up at least an additional ADC and then maybe it could be processed to simulate the filtering.... (as two pins of PortB only used for the ISP connector, during normal usage these are just wasted, could be repurposed; using external oscillator on PortB6, the PortB7 is also available for I/O)
I'm yet to know the more in depth operations, but dated and different generation's source codes doesn't helping in the looking for potential optimization/idle cycles to fit in some of the above.
I've already laid out a board with the paddles connected, but without any pin swapping, so it's still 100% compatible with the older versions.
What do you think about this?