;@ outs a a
opcode FxIn, 0, kkkkk
  kS, kOnOffSw, kPad, kzL, kzR xin
  kPad += 1
  aL = (gaFX1*(1-kS) + gaFX3*kS) * kPad * kOnOffSw
  aR = (gaFX2*(1-kS) + gaFX4*kS) * kPad * kOnOffSw
  zaw aL, kzL
  zaw aR, kzR
endop
