Tandy Corporation

Robert Cook

Gerald Stuteville

Robert Sanford

The invention comprises a telephone answering device in which a microprocessor controller is coupled to all of the peripheral components through a single common multi-bit data/instruction bus and each peripheral component is coupled to the data bus through a latch which is enabled responsive to an enable instruction placed on a port of the controller.

Telephone answering device with standardized internal bus

A circuit for generating a bias signal and an erase signal for use in a recording apparatus having a record head for recording an input analog signal on a magnetic tape, and an erase head for erasing information from the tape. A DC erase signal is applied to the erase head in response to the erase control signal to cause the erase head to erase information. An AC bias signal is generated and is combined with the input analog signal to make a record signal. The record signal is applied to the record head in response to the record control signal to record information on the tape. A controller generates an erase control signal and as record control signal. The AC bias signal is generated by an AC bias oscillator, such as a Hartley oscillator to reduce the noise contributed in the recording system. Use of a DC source to drive the erase head reduces the cost of the circuit, while maintaining a significant increase in the signal-to-noise ratio.

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Lewisville, TX, United States of America

Robert Cook