Abstract: An automated telephone calling system receives a group of telephone numbers from a host computer. For each telephone number there is a corresponding record of unique information. The host computer is connected to drive a plurality of operator display terminals. Each number is automatically called and equipment provides detection of rings, busy signals, recordings and voice answers. When a party answers a call, the called line is connected to a non-busy one of a group of operations. At the same time a report is sent from a central controller to the host computer reporting which number has been successfully called and which operator has been selected for the audio connection. The host computer then calls up the record for the called number and transmits at least a portion of the record to the display for the selected operator. The operator is thus provided with an audio connection to the called party as well as a screen display of relevant information for that party.

Abstract: Telephone call progress tones are identified by measuring the periods of their envelope cycles in the range of 20 to 200 Hertz which are due to the difference frequency of the signals used by phone company to form the call progress tones. The periods of the envelope cycles are classified, and a decision is made by a programmed microprocessor by comparing the data derived from the unknown signal to what is expected for known call progress calls of many telephone companies. In making such decision, the several period measurements are accumulated in bins, and the bin reaching the largest total is used to develop a representative period which is examined, if various other criteria are met, to identify the call. In this process, substantially regular envelope cycles are selected, and noise is rejected. An answer to the call is detected by this technique.

Abstract: A method and apparatus are disclosed for recording digital data on magnetic tape with an audio recorder. A logic circuit receives the data to be recorded and outputs two sequences of high and low levels: one sequence directly corresponds to the data and the other inversely corresponds to the data. One sequence is first inverted with respect to the other and the two sequences are then combined and recorded. After a data sequence, the two logic circuit outputs are placed at the same level, and the subsequent inversion of one output level relative to the other causes the combined levels to reach an intermediate, third level.