Voice Interface Parts list SP0256 AL2 Speech generator IC VIA 6522A Standard interface circuit. Make sure to get the 2MHz (A) version! 741 or LM324 Op-Amp or Quad Op-Amp. 3.12Mhz Crystal 2x22pF 10nF 470uF 2x220nF Capacities 2x33K 1K 8.2K 2.7K Resistors