auto APU::Channel5::run() -> void {
int11 output = (int8)s.data;
switch(r.scale) {
case 0: output <<= 3 - r.volume; break;
case 1: output <<= 3 - r.volume; output |= -0x100 << (3 - r.volume); break;
case 2: output <<= 3 - r.volume; break;
case 3: output <<= 3; break;
}
o.left = r.leftEnable ? output : (int11)0;
o.right = r.rightEnable ? output : (int11)0;