Khaled Abdel-Ghaffar - Davis CA
Martin A. Hassner - Palo Alto CA
International Business Machines Corporation - Armonk NY
A method and means is described for correcting multiple error bursts in data recorded on a storage medium in blocks, comprising a plurality of subblocks. After reading the data, decoded block check syndromes are algebraically summed with estimated block check syndromes to provide a set of syndromes for a code for locating subblocks having an error burst. This set of syndromes is decoded to identify each subblock having an error burst. Concurrently block level syndromes are computer to identify the locations and values of errors within the subblocks having error bursts. During writing, the data in all subblocks of a block is encoded and block level syndromes are generated for these subblocks. These block level syndromes are multiplied by a series of preselected weighting factors (. alpha. sup. 1. . . alpha. sup. 1(B-1)) according to the location index 1 of the sublock within the block and as multiplied, each is stored in a different one of B buffers.