Milgo Electronic Corporation

Racal-milgo Limited

Judson Truman Gilbert

Ran-Fun Chiu

James Bryon Sherman

Michael Levy

John B Scott

George R Harrison

Alan R Holbrook

Harris K Swan

A data display communication system wherein data generated locally by a keyboard or generated remotely and communicated by modems is displayed on a display device. Data displayed on the screen can be edited or reformatted prior to storage, print-out, or transmission to a remote location. Data communicated between storage and the central processing unit is handled in blocks that make up one full line of characters on the display device. All edit and format functions are performed on the basis of these blocks of data. Timing for the display device controls the operation of the system. The communication system utilizes a microprocessor operating in conjunction with specific hardware logic to handle display oriented operations.

Microcomputer data display communication system with a hardwire editing

In a phase-modulated communication system utilizing voice-band communication channels wherein phase-jumps may be experienced, a phase-jump detector indicates the occurrence of such phase-jumps. A phase-jump corrector responds to the persistence of a phase-jump condition by correcting for it without requiring shut-down and complete reequalization of the transmission channel. Monitoring of the incoming signal for phase-jump occurrence provides a convenient signal quality indication that represents the magnitude of the error in the X and Y components of each received symbol.

Phase-jump detector and corrector method and apparatus for

A phase modulation modem providing switch selectable speeds on voice-band channels utilizes four phase, modified eight phase, and optimized eight phase, two amplitude modulation techniques. A binary equalizer automatically corrects for envelope delay and amplitude distortion of the carrier signal caused by the voice-band channel. Each symbol time, the X-axis error and Y-axis error for the received symbol is determined by comparing the received X and Y components with stored ideal X and Y components for that symbol. These error X and error Y values are used to modify primary and secondary equalization constants. The equalization constants, thus modified during this symbol time, are used on the next received symbol to correct for the phase and amplitude distortion measured during past symbol times. This sequence is repeated for each symbol time. Preselected equalization constants are utilized on the first symbol received. To equalize the line very rapidly at start-up, a phase training signal is sent prior to data transmission. After this 'course' adjustment the equalizer operates on the received data symbols to very accurately correct the phase and amplitude distortions of the received symbols. A symbol quality signal is conveniently generated as a result of the equalizer operation.

Method and apparatus for performing binary equalization in voice-band

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Hialeah, FL, United States of America

Judson Truman Gilbert