METHODS AND APPARATUS FOR DATA STORAGE ON MAGNETIC MEDIA INCLUDING ERROR CORRECTION CODES
In a digital data storage system providing two or more levels of interleaved Reed-Solomon error correction coding together with a track checksum, the track checksum is calculated according to an algorithm which has no correlation with the Reed-Solomon codeword generation rules. This allows miscorrections at the C2 correction level to be determined reliably thereby enhancing the correction rate. Also disclosed is a system which uses the enhanced ability to identify C2 miscorrections, to mark C2 miscorrections to the third level of error correction thereby allowing double error correct at the third level.