Commodore Business Machines, Inc.

Robert J Raible

Hedley C Davis

David W DiOrio

Bruce F Ahrens

Chaoynan E Yang

A computer system mouse-type input device. Movements of a track-ball motion sensor are converted to quadrature signals and are accumulated in a counting circuit. The contents of the counter are pulse-position modulated with waveforms characteristic of a resistive-capacitive charging circuit and are read periodically by a computer input channel normally used for input of potentiometer-generated commands. The pulse-position modulated signals are converted to digital values used by the computer to position the cursor on a display screen.

Circuit for interfacing mouse input device to computer system

Programmable I/O (input/output) interface circuitry provides video and audio signals, needed for a video computer/game, to a commercial color television type display/monitor and may be implemented in HMOS, (H type metal oxide semiconductor) large-scale-integrated circuitry. The system architecture allows for reduced chip count, and improved reliability while providing adequate synchronization pulses, luminance level signals, chrominance phase shift signals, raster control and cursor control video and three independently controlled audio voices. A software selectable keyboard latch input, plural speed processing for faster operation when outside the active display area or during blanking, all system control signals necessary for system operation and 3 independently controlled interrupt generating timers are also provided.

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Audubon, PA, United States of America

Robert J Raible