High areal density recording using an MR/inductive head and pre-embossed rigid magnetic disk

To determine whether a newly developed PERM (Pre-Embossed Rigid Magnetic) disk can be used with an MB/inductive head and a PRML (Partial-Response Maximum-Likelihood) channel, an experimental digital magnetic recording system was developed. This system used an external clocking scheme instead of a conventional self-clocking scheme. The track pitch was 5.2 /spl mu/m, and the track width was 3.6 /spl mu/m. Basic read-write characteristics, such as signal-to-noise ratio, frequency response, positive/negative symmetry or the readback pulse, were measured. An areal density of 605 kbit/mm/sup 2/ (390 Mbit/inch/sup 2/) was obtained at a bit error rate of 10/sup -6/.<
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