name: HT9315FC function: 14-Memory Tone/Pulse Dialer package: DIP20,20 manufacturer: Holtek +--()--+ C1B | 1 20| R4B C2B | 2 19| R3B C3B | 3 18| R2B C4B | 4 17| R1B C5B | 5 16| MODE X1 | 6 15| DTMF X2 | 7 14| POB XMUTEB | 8 13| HKSB VSS | 9 12| VDD DOUT |10 11| CLOCK +------+ This pinout came from the Chipdir: http://www.chipdir.org/