Abstract: A method for correcting error bursts in data which are uncorrectable by an ECC in a communications channel in which no pointer is available or if available is not generated. The data is recorded in blocks preferably comprising subblocks. Parity cell syndromes are generated for each block during writing; and during reading these syndromes are analyzed to identify possible starting points of error burst locations. A trial correction is applied to the data in the uncorrectable block (or subblock), then verified whether successful using CRC. The correction is accepted as valid if and only if only one trial correction is verified as successful. The maximum number B of consecutive bytes in error correctable in a block is less than, the number N of bytes in each parity cell, and N-B is selected to limit the probability of miscorrection.

Abstract: Systematic and noise-induced errors, as detected in words extracted from corresponding locations in a m .times. n word organized memory array, are distinguished as to their source and are corrected by using the conjunction of a nonzero error checking syndrome and the a'priori location defects status as indexed by the location address of the extracted words from an external table memory.

Abstract: A rotating field access pattern for use in the propagation of a bubble lattice is disclosed. The pattern contains a set of diamond shaped magnetic elements arranged in a regular array. The elements have two sides which are parallel to one bubble lattice axis and two sides which are parallel to another bubble lattice axis. The bubbles are propagated in the direction of a third bubble lattice axis.