Browse Prior Art Database

Magnetic Tape Error Correction Systems

IP.com Disclosure Number: IPCOM000080710D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Irwin, JW: AUTHOR

Abstract

In many magnetic tape oriented error correction apparatus, signal quality indicating signals, commonly referred to as "error pointers", enhance the error correction capability of the error correction apparatus. Generally, such error pointers are track oriented; that is, if an error pointer is generated at the defect in track 4, that pointer is exclusively for error correction in track 4. When the data set on the tape includes bytes extending across the tape from tracks 1-7 in an ordered fashion, such error correction procedures are satisfactory.

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Magnetic Tape Error Correction Systems

In many magnetic tape oriented error correction apparatus, signal quality indicating signals, commonly referred to as "error pointers", enhance the error correction capability of the error correction apparatus. Generally, such error pointers are track oriented; that is, if an error pointer is generated at the defect in track 4, that pointer is exclusively for error correction in track 4.

When the data set on the tape includes bytes extending across the tape from tracks 1-7 in an ordered fashion, such error correction procedures are satisfactory. However, in some tape systems, adjacent tracks contain unrelated data sets; for example, if each track of the seven tracks in the illustration contained its own respective serially recorded data sets plus associated error correction codes and apparatus, then the illustrated defect not only could affect track 4, from which a pointer would be generated, but also could induce errors during the readback of tracks 3 and 5.

Accordingly, whenever an error is detected in tracks 3 and 5, the electrical circuits could look for pointers in adjacent tracks. Track 3 would look for pointers in tracks 2 and 4, while track 5 would look for pointers in tracks 4 and 6. Then, based upon an error correcting apparatus indicating an error condition in one of the two tracks 3 or 5, such pointers can be transferred for usage to an immediately adjacent track. The effect of the defect on adjacent tracks may b...