Radially-coherent reading and writing system and method for a magnetic disk

摘要

Radially-coherent data reading from, and data writing to, a magnetic disk use non-coherently written synchronization signals on the disk. In a form, the radially-coherent data reading and writing is performed using a magnetic head/disk tester which includes a spinstand for supporting a spinning magnetic disk, a magnetic head assembly, a write channel network for generating a write data signal for application to a write element of the magnetic head, a read channel for receiving a read-back signal from a read element of the magnetic head assembly, and a signal processing system that analyzes a read-back signal from a disk and provides synchronization signals for radially-coherent data reading and data writing.

主权项

1. A method for preparing a magnetic disk for storing radially coherent data on a plurality of mutually adjacent, concentric tracks disposed about a disk axis on a major surface of the disk, comprising the steps of:
A. defining a synchronization area and a data area for each of a plurality of circumferentially extending sectors of the tracks, wherein each sector is bounded by a radially extending sync start reference line and a radially extending sync stop reference line, wherein for each sector,
i. the synchronization area includes a portion of the plurality of tracks extending circumferentially from the start reference line of that sector to a radially extending sync stop reference line of that sector, andii. the data area includes a portion of the plurality of tracks extending circumferentially from the sync stop reference line of that sector to the data stop reference line of that sector, B. writing to the synchronization area of each sector on the disk, wherein the writing step comprises the sub-steps of:
i. defining a pair of sync signals, wherein each sync signal has no correlation with itself, has no correlation with the other sync signal,ii. rotating the disk about the disk axis,iii. positioning a magnetic write head over a succession of the mutually adjacent tracks, from an innermost or an outermost of the tracks, enabling writing to the respective tracks in response to signals applied to the head,iv. during the rotation of the disk, with the write head over a first set of alternate ones of the tracks, applying a first of the pair of sync signals to the write head whereby the first sync signal is written to a first fraction of the synchronization area for each sector, and establishing that a second fraction of the synchronization area for each sector of the first set of tracks is characterized by a magnetization representative of all digital 1's, all digital 0's or is demagnetized, andv. during the rotation of the disk, with the write head over a second set of alternate ones of the tracks, applying a second of the pair of sync signals to the write head whereby the second sync signal is written to a second fraction of the synchronization area for each sector, and establishing that the first fraction of the synchronization area for each sector of the second set of tracks is characterized by a magnetization representative of all digital 1's, all digital 0's or is demagnetized.