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Tape Error Correction

IP.com Disclosure Number: IPCOM000094644D
Original Publication Date: 1965-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Freiman, CV: AUTHOR [+3]

Abstract

Certain error detection and correction methods, used in parallel track recording systems such as magnetic tape, combine a track-locating error detection code with a vertical redundancy check (VRC) to correct single errors occurring in a particular character. The track locating error detection apparatus detects an error when the record is read and indicates in which track the error occurs. A second read pass is necessary to correct the error by inverting the bit in the character which indicates a VRC error.

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Tape Error Correction

Certain error detection and correction methods, used in parallel track recording systems such as magnetic tape, combine a track-locating error detection code with a vertical redundancy check (VRC) to correct single errors occurring in a particular character. The track locating error detection apparatus detects an error when the record is read and indicates in which track the error occurs. A second read pass is necessary to correct the error by inverting the bit in the character which indicates a VRC error.

Permanent errors are corrected each time a record is read, which necessitates two read passes over an erroneous record. A single read pass accomplishes the same results, if the record containing a permanent error is prefixed with a single character record. The latter identifies the track in error the first time the error is encountered on a read pass. Thereafter, the correction can be done on the first read pass.

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