FORMAT FOR DATA-STORING DISK MEDIA WHEREIN ADDRESSABLE TRACK ANGULAR LENGTH IS INDEPENDENT OF DISK REVOLUTIONS

摘要

Data-storing disks, preferably each disk having a single spiral track, have addressable tracks that are independent of the length of disk or spiral track revolutions. Each revolution may contain a non-integral number of addressable tracks and sectors. An optical disk is used to describe the invention. The circumferential location of the tracks and sectors precess circumferentially. A plurality of radially disposed revolution bands each contain a fixed number of the revolutions an increasing number of the addressable tracks in the radially outer more ones of the bands. It is preferred that the number of bands be 2n, where n is an integer. Each band is divided into a plurality of revolution groups, each group having a fixed number of revolutions. Each group in a band has a like number of the addressable tracks. A so-called anchor sector has one end anchored to a reference circumferential position on the disk. Each revolution group begins with an anchor sector, all other sectors in the group are positioned circumferentially with respect to the anchor sector. Addressable track seeking, alternate embodiments and fabrication of a disk are described.