A CODING AND DECODING METHOD OF TRACK ADDRESS WITH VITERBI DECODING

As the recording method for the track address in the magnetic disk dri ve, the Gray code with redundancy (Gray-like code) has been used so th at nearly the correct value can be obtained even if the head is locate d close to the track boundary. This paper proposes a recording/reprodu cing method for the track address in the magnetic recording where the Viterbi decoding is applied to the Gray code record. The detection per formance is evaluated by the theoretical analysis and the simulation. As a result, it is seen that the same or better performance compared t o the conventional method can be obtained. By the proposed method, the area for the track address recording can be reduced to one-half to tw o-thirds the conventional method. This helps to increase the recording capacity and improve the maximum seek time.