Soundstream, Inc.

Bruce C Rothaar

Thomas G Stockham, Jr

The present invention includes an arrangement for averaging the content of first-in-first-out buffers of each track of a multi-channel digital tape recorder for controlling tape speed to enable a smooth over-dubbing of information recorded at different times on separate tracks.

Uniform speed control for a multi-channel digital recorder

The synchronization circuitry can be described as operating in essentially four states and is particularly useful at startup, to locate synchronization codes and spacing there between in the data flows. In operation, the synchronization circuitry looks in a data flow at startup for any sync code and, when such sync code is found, counts ahead to where the next sync code should be. If a proper sync code is found, again the circuitry counts ahead to where the next sync code should be, continuing looking at points along the data flow until a certain number (n) of properly located sync codes are discovered whereat synchronization is declared and normal playback is ordered. However, if sync codes are not located where they should be in the data flow, then such failures are subtracted from success until either (n) successes are found or a total of successes less failures reaches zero whereat the circuitry returns to the first state of looking for any sync code.

Apparatus and method for requiring proper synchronization of a digital

The present invention involves an apparatus and method for processing of digital information that includes duplication of information from each channel of a multi-channel recorder on main and backup tracks and provides a combination of error detection apparatus and procedures where data groupings or words on each track are individually subject to four separate tests for detecting errors and provides, from that analysis, for a selection of most likely correct data for further processing. Additionally, further system reliability is obtained by providing circuitry whereby a detected error activates a selection of data groupings coming before and after the detected error, providing where appropriate, for switching from main to backup track data over a certain number of data groupings. The present invention further provides a unique synchronization coding format with circuitry and a procedure for its use for rapidly acquiring synchronization coding in a data flow and includes an arrangement for averaging the content of first-in-first-out buffers of each track for controlling tape speed to enable a smooth over-dubbing of information recorded at different times on separate tracks.

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Salt Lake City, UT, United States of America

Bruce C Rothaar