%import textio %zeropage dontuse %option no_sysinit main { ; $1F9C0 - $1F9FF PSG registers sub start() { ubyte xx=33 when xx { 1 -> { } 2 -> { } else -> { } else -> { } } ; uword freq = 1181 ; cx16.vpoke(1, $f9c0, lsb(freq)) ; cx16.vpoke(1, $f9c1, msb(freq)) ; cx16.vpoke(1, $f9c2, %11111111) ; volume ; cx16.vpoke(1, $f9c3, %11000000) ; triangle waveform } }