JPS6467765A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent malfunction of a host device by writing data other than a gap pattern from the finishing point of writing the final recording up to an index as a padding gap and inhibiting an address mark detection during the detection of this padding gap. CONSTITUTION:An area from the finishing point of the final recording 6b to the index 1 is written with the padding gap 8 of a different data pattern from the data pattern of the gap 7. To detect this padding gap 8, a detecting circuit 20 is provided, where a frequency of a read signal 21 of the detecting circuit 20 is discriminated, and when it coincides with a frequency of the padding gap, a padding gap detecting signal 10 is outputted. The padding gap detecting signal 10 is inputted into an address mark detecting circuit 23, thus inhibiting the detection of the address mark. By this method, even when a medium defect exists to detect erroneously the address mark during the padding gap detection, the detecting erroneously the address mark is thus eliminated.