Abstract: In the system of the present invention, the system includes a pre-synchronizer to eliminate the need for examining every possible substring preceding the EOP (end of preamble) mark in order to detect the EOP. For the case where autocorrelation techniques are used to provide error synchronization error tolerance, this results in a much shorter EOP, since it is possible to find shorter EOPs which do not falsely synchronize prior to the arrival of the true EOP. In particular, the preamble is utilized to perform pre-synchronization. Once pre-synchronization has been achieved, the search for the EOP can be focused on a subset of all possible substrings as opposed to prior techniques which looked at all possible substrings. The resultant system solves the problem with less logic and more error tolerance.

Abstract: The present invention includes a method, apparatus and disk format for implementation of the same to provide fault tolerant detection of ID fields for data sectors in order to eliminate errors caused by mis-alignment and mis-detection of hard sector marks. Logic is provided to initiate a time-out count at the completion of a hard sector count. The time-out count is specified to be a period of time within which a hard sector mark should be detected. If the time out count counts down and a hard sector mark is not detected, then a possible error situation arises and the fault tolerant process is initiated to compensate for the lack of detection of a hard sector mark. Thus, at the end of the time-out count, a small burst count is started.