TH19447B - Disk drive for data storage. - Google Patents

Abstract

A zone-bit, sector-based servo disk drive utilizes a sector architecture where the write head locates and identifies data sectors. Instead of using a data sector ID field, it uses information obtained from electronic storage and servo sectors, which are not necessarily adjacent to the data sector. Tracks carry servo and data information, but no sector ID. Each zone track is divided by a circumference into several segments. Within each segment is a data storage area separated by servo sectors. This storage area may contain partially filled or fully filled data sectors. Formatting information is provided to identify and locate data sectors, including those whose data area is not adjacent to the servo sector. There is a single input unit for each area in a section, and each input unit contains a segment of the data sector. The first and last in that area?? Whether it's the sectors represented by those sections, they are divided between two areas, with the total number of data sectors in that area and the sector number of the first data sector in that area?? The information provided in such a cersosector consists of a cersosector number or another index, which allows the disk drive to determine the position of the writing head and begin reading or writing immediately upon aligning with the track, without causing any adverse waiting time.

Claims (9)

1. A disk drive is made up of a type of disk (204) that contains a number of circular data tracks (218) that are divided into a number of radially spaced regions (251, 252, 253) and N of equally spaced servo sectors (220) that extend radially across the zones. Each track in at least one zone contains M (254) data sectors, each data sector containing the same number of bytes of data, and a write head (208) for reading data into the servo sectors and for writing and reading user data into the data sectors. A special feature is that the data sectors include non-identifying data (IDs) that identify the data sector. The disk drive also has the special feature that a servo sector counter (414) responds to data read by the write head into the servo sectors to count the servo sectors as the disk rotates past the head. Memory (422) stores formatted track data representing the position of data sectors relative to servo sectors in the track, and sector logic circuit (454) is connected to the servo sector counter and memory to indicate the position of the data sectors where user data is read or written from the formatted track data. 2. A disk drive as described in Claim 1, in which the memory also stores an indentation value that represents the offset of the number of data sectors of a data sector in the first track of at least one such zone from the data sectors that are radially placed in the second track of the same zone. 3. A disk drive as described in Claim 1 or Claim 2, where each track in at least one zone is divided into a number of unique track segments, each segment having n servo sectors and m data sectors, where m/n is the reduced integer ratio of M/N, m data sectors are separated into data sections by m servo sectors in each segment, and where the formatted data of the track stored in the storage unit is required by track segment data representing the position of the data sector relative to the servo sector within the segment. 4. The disk drive as specified in claim 3 also includes a servo-modulo counter connected to a sector logic circuit for generating a resettable servo-modulo counter every n servo sectors from known values of m and n, where a represents the number of servo sectors within a track segment. 5. A disk drive as specified in claim 4, where the memory unit can be addressed by the number of servo sector track segments generated by the servo-modulo counter. 6. A disk drive as specified in any of Claims 3 through 5, in which the memory unit stores the length of the first and last data segments in a track segment. 7. A disk drive as specified in any of Claims 3 through 6, where the memory unit stores the number of complete data sectors in a track segment. 8. A disk drive as described in the preceding claims, where each track includes an index marker that serves to indicate a fixed location on the track representing the start of the track, and where a servo sector counter responds to the index marker. 9. A disk drive as described in Reputation 1, where tracks in at least one zone are divided into a number of characteristic track segments and partial segments, where the partial segments include stubs of length less than the data sector; each characteristic track segment includes n' servo sectors and m' data sectors, where the m' data sector is split into data sectors by servo sectors, such that if m/n is the least integer fraction of M/N, then the resultant of the stub is m'+n' less m+n.