Toshihiko Hirose

8/10PR1ML for high density and high rate tape storage systems

We applied class-1 partial response maximum likelihood (PR1ML) combined with a dc-free code rate of 8/10 (8/10PR1ML) in tape storage systems in which linear density was higher than 115 kbpi and channel rate was above 50 Mbps. This paper describes the performance of 8/10PR1ML in simulation and in practice, and of a parallel Viterbi detector specialized for PR1ML. A bit error rate of less than 10/sup -6/ was achieved at an areal density 265 Mbpi/sup 2/ in practice. The maximum clock frequency of the parallel Viterbi detector was MIN. 75 MHz, TYP. 120 MHz and its size was less than 1200 gates.

Development of high density recording for advanced tape streamer

A high density magnetic recording for a helical-scan tape recorder has been developed. Tape-head characteristics and a PRML-class 1 detecting method with adaptive digital equalization are discussed and a new auto tracking following technology has been proposed. Using these technologies, we have achieved symbol error rate less than 1*10E-5 at an area density of 268 Mbit/inch/sup 2/. As a result, we have successfully demonstrated an advanced tape streamer with a transfer rate of 24 Mbps and a capacity per cassette of 25 GB.