This was used for the blueflame music for demosplash2023

mockingboard_init.s
	assume slot #4
	only one channel
	sets up interrupt handler
tracker_init.s
	clear mirror registers in ZP to 0
	($70-$83?)
	if any register always same, set it ($38 to mixer?)
	

play_frame.s
	has amplitudes to rotate through on A/B channel
	
	; NNNNNEEC -- c=channel, e=end, n=note
	; 32 notes, 4 lengths, 2 channels


Original tiny tracker6:
	2 channels