| 摘要 |
A magnetic data storage disk record carries a pattern of magnetic domains defining a plurality of concentric data tracks divided into data sectors by embedded servo sectors recorded at a predetermined constant frequency and containing head positioning information for positioning a data transducer head for reading the disk track. Each data sector is recorded at a data transfer rate selected in relation to displacement of the track from a center of the disk. Each data sector defines a plurality of variable length data segments which are combined to provide a fixed length user data block. In order to avoid a write-to-read transition and Barkhausen noise, each data sector begins with an ID header immediately following a servo sector. The ID header includes a plurality of count byte fields for providing a count of bytes of each one of the user data segments within the data sector, and a flag field for indicating whether the user data block begins at the first data block segment of the particular data sector. A disk drive data sequencer using the count bytes and flag bytes is also disclosed. |
