name: HT93215A function: 1-Memory Tone/Pulse Dialer package: DIP16,16 manufacturer: Holtek +--()--+ HKSB | 1 16| R4B MODE | 2 15| R3B X1 | 3 14| R2B X2 | 4 13| R1B VSS | 5 12| C3B VDD | 6 11| C2B DTMF | 7 10| C1B XMUTEB | 8 9| POB +------+ This pinout came from the Chipdir: http://www.chipdir.org/