nes-apu-node demo

Pulse 1 Pulse 2 Triangle Noise
$4000 -------- $4004 -------- $4008 -------- $400C --------
$4001 -------- $4005 -------- $4009 -------- $400D --------
$4002 -------- $4006 -------- $400A -------- $400E --------
$4003 -------- $4007 -------- $400B -------- $400F --------
Status
$4015 --------