I have added a noise channel component for the FM chip of my SEGA Mega Drive MIDI Interface. The aim is to simply offer a little more variety in terms of what sounds can be achieved with the YM2612, so it's quite basic at the moment. The channel (which is actually a 'half channel' as it is split with FM channel six / the DAC channel) has the following features:
• 3 bit volume control is mapped to velocity
• 6 bit frequency control is mapped to pitch (specifically, notes 0 - 59)
A demo video is below.