IBM PC Voice Mail Cards

Abstract

The Voice Main Card (VMC) functions as an enhanced telephone answering machine and is designed as a plug-in card for the IBM PC and compatibles. In addition to standard answering machine functions, the VMC features programmable outgoing message selection, message routing, response to caller's touch tone signals, and remote programming ability. The VMC will answer incoming telephone calls, deliver outgoing messages which are Programmably selectable from as many as 16 digitized audio messages stored on the PC's hard disk, record incoming messages to the hard disk or optionally to an external tape recorder, route messages to a specified receiver, respond to a caller's touch tone signals, and enter a remote programming mode as a result of a special code sent by the caller. Audio messages are processed digitally via A/D and D/A converters which receive and send 8-bit data to and from the IBM PC through a selectable port address. The A/D conversion is implemented with the ADC0802 which is operated at a clock rate of 512 kHz. The D/A conversion is implemented with the DAC0830. Interface with the telephone line is accomplished with the speech circuit TP5700 coupled through opto-couplers. Messages are recorded using an external 600-ohm dynamic microphone and played back through an external 8-ohm speaker. A full-featured, pull-down menu program is provided with the VMC and implements all programmable functions. Data In/Out (I/O) with the card is interrupt-driven to allow apparent simultaneous disk I/O.