Abstract: A computer inputed with a data base of potential call recipients and having an EIA RS-232 Data Communication Equipment interface drives an auto-call unit or dialer through a format conversion device to be compatible with the dialer EIA RS-366 automatic calling equipment interface. A line signalling device monitors the dial stream for conference connection commands and establishes a voice connection between the computer, an external or remote station and an internal or local extension upon receipt of such command. The computer thereupon disengages itself from the conference connection while maintaining the same between the remote and local stations. While a previously established conference connection may continue to be in progress, the computer is free to process a new sequence of dial digits from the data base to establish a conference connection between a next successive group of handsets in an automated, high speed repetitive manner.