Otari Electric Company, Ltd.

Personics Corporation

Thomas D Sharples

John C Weitz

Michael L Collette

Hugh Macdonald

George Wong

Ichyterra Ganapathy

Kelly Quan

Charles E Garvin

Michael Poimboeuf

Data processing system for high-speed reproduction of musical recordings at a point-of-sale terminal utilizes optical CD music ROM banks of master programs prerecorded by a Dolby ADM (adaptive delta modulated) technique to condense their 'information' content. Condensation permits higher data throughput during high-speed reproduction. In a 'premastering' process to make encoded masters, a special multiplexer board provides interfacing between Dolby ADM digital audio data and a conventional data processing system. The multiplexer board performs computer-like data blocking and also writes a unique sync code directly in the data block. The data processing system also catalogs and edits the blocked digital audio; places encrypted catalog, pricing, and other indicia in the data file representing the music; and sends the data file to convention 16-bit PCM file writer for making the encoded CD music ROMs which contain the ADM data representing the encoded audio program. A high-speed reproduction device, under control of a desk top personal computer, extracts timing and ADM data from the CD music ROM at high speed and controls high-speed tape drives to compile selected recordings on a single cassette tape in a form compatible with Dolby B noise reduction.

High-speed reproduction facility for audio programs

A synchronizer for synchronizing a slave tape recorder to a master tape recorder. When the speed of the master recorder exceeds 2.5 times the nominal play speed, the synchronizer causes the slave recorder to lag behind the master recorder by an amount related to the speed of the slave recorder. At lower speeds, the synchronizer causes the slave recorder to lock onto the position and speed of the master recorder. The synchronizer employs time-code readers to read time-code on address tracks on the master and slave recorders. The time-code readers produce not only time-code but also clock pulses which are employed to determine the speed of master and slave with high resolution. Both the time-code readers and a resolver employed in the synchronizer are constructed from gate assemblies rather than processors to reduce execution times for the processor in the synchronizer. The resolver is a digital resolver which includes a phase comparator which produces pulses having a width related to the phase difference between indications of the synchronization word in the time-code and polarity to indicate whether the master leads or lags the slave. This signal is applied to a counter which generates a digital error signal based on the phase difference which is employed to control the speed of the slave recorder.

Synchronization method and apparatus

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Redwood City, CA, United States of America

Thomas D Sharples