Abstract:
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. There is further provided 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 buffes of each track for controlling tape speed to enable a smooth over-dubbing of information recorded at different times on separate tracks.
Abstract:
Apparatus and techniques for converting analog data, preferably audio signals, to digital information, which digital information is preferably recorded from two separate main channels (11, 12) onto main tracks (22a, 22b) and includes a third or backup track (22c) for recording thereon partial or most significant portions of that information recorded on the main tracks. The invention involves apparatus and techniques of each data group on each main track and the backup track; checking (27) for synchronization codes arranged between data groups; and checking (30) for a match of that appropriate portion of the main track data against the data on the backup track, with, when potentially erroneous or questionable data is detected, the invention providing for comparison of main and backup track data groupings (31) for determining which is most likely correct or, in the case where neither data grouping is identifiable as most likely correct, the invention provides for substitution of last correct data or integration between good data. The preferred invention incorporates clocking at the signal input for data stabilization, and first-in-first-out circuitry (32) at the output for reducing the effects of wow and flutter to produce a very high quality conversion of digital to analog form to pass to a speaker system.