| 摘要 |
A disk drive for storing data in a tabular format provides fast access to both rows and columns by superposing a pair (5, 7 Fig. 4) of oscillators upon an overall spiral motion (4) of a head able to access records on the disc, so that segments in a plurality of different tracks may be accessed within one revolution of the disc. Two heads oscillating in antiphase may enable all segments in all tracks to be so accessed (Fig. 5). The data may be stored in such a way that when an element changes, only that element is recorded again and not the record to which it belongs. Write-once-only optical disks may thus be made suitable for storage of live data and not just for archiving. <IMAGE> |
