Magnetic disk drive apparatus including improved decoding circuit

摘要

A magnetic disk drive apparatus can reduce the production probability of failed sector due to the fact the a decoding start synchronization mark can not be detected in reproduction of data on a magnetic disk and can utilizes the capability of an error correction circuit sufficiently. A plurality of decoding start synchronization marks are provided in each sector of the magnetic disk and when any one of the decoding start synchronization marks can be detected, a decoding circuit can be operated.