Abstract: Analyzing magnetic media surfaces for thermal erasures and other characteristics is described. The system includes a drive channel module configured to measure servo automatic gain control values for a magnetic media surface that represent the amount of gain applied by the drive channel module to a preamble signal recorded on the magnetic media surface. The gain control values are then acquired according to certain measurement parameters. The gain control values are then arranged by proximity to each other and organized to generate images that represent changes in the characteristics of the magnetic media surface. Analysis of the images then detects patterns that represent changes in the characteristics of the media surface and determines measurement parameters that coincide with the change in the characteristic.

Abstract: Analyzing magnetic media surfaces for thermal erasures and other characteristics is described. The system includes a drive channel module configured to measure servo automatic gain control values for a magnetic media surface that represent the amount of gain applied by the drive channel module to a preamble signal recorded on the magnetic media surface. The gain control values are then acquired according to certain measurement parameters. The gain control values are then arranged by proximity to each other and organized to generate images that represent changes in the characteristics of the magnetic media surface. Analysis of the images then detects patterns that represent changes in the characteristics of the media surface and determines measurement parameters that coincide with the change in the characteristic.

Abstract: A track map of a disk drive is generated to compensate for various conditions. A track map is a stored measurement of every “half” servo track width on a disk. Every servo half track width is measured in the factory on a disk and then the data is stored on the disk for use during drive operations. When an individual track is accessed, the appropriate servo half track width data is pulled from memory and is used to adjust a scale factor for that local half track width. The track map may be used to compensate for various conditions including varying servo track width, microjog distance, and data track spacing.

Abstract: A track map of a disk drive is generated to compensate for various conditions. A track map is a stored measurement of every “half” servo track width on a disk. Every servo half track width is measured in the factory on a disk and then the data is stored on the disk for use during drive operations. When an individual track is accessed, the appropriate servo half track width data is pulled from memory and is used to adjust a scale factor for that local half track width. The track map may be used to compensate for various conditions including varying servo track width, microjog distance, and data track spacing.

Abstract: A track map of a disk drive is generated to compensate for various conditions. A track map is a stored measurement of every “half” servo track width on a disk. Every servo half track width is measured in the factory on a disk and then the data is stored on the disk for use during drive operations. When an individual track is accessed, the appropriate servo half track width data is pulled from memory and is used to adjust a scale factor for that local half track width. The track map may be used to compensate for various conditions including varying servo track width, microjog distance, and data track spacing.

Abstract: An apparatus includes a unit that uses a head with spaced read and write portions to write and read information to and from an information storage medium. According to one feature, a desired position for the write element is converted into a position for the read element as a function of a polynomial. According to another feature, the unit uses the head to write and read back selected information in order to determine compensation information, the receiving unit subsequently effecting writing of information with the head as a function of the compensation information. On a more specific level, the unit can removably receive a cartridge that contains the information storage medium.

Abstract: An information storage device (10, 510, 610, 710, 810) includes a cradle (12, 512, 612, 712, 812) which can removably receive a cartridge (11, 411, 511, 611, 711) that contains a rotatable hard disk (91, 326-327). A read/write head (107, 331-334) is supported for movement adjacent the disk by a pivotal actuator arm (101). The cradle controls alignment of the head with the disk using feedback servo tracking. Calibration parameters used to perform this tracking, such as servo information or read channel information, may be stored in a special track (414) which is on the disk, and which may be a read-only track. The special track stores a plurality of sets of calibration parameters, each corresponding to a respective combination of a cradle and an environmental characteristic such as temperature.

Abstract: A disk is manufactured having a reduced capacity based on a quantity of addressable and non-addressable portions. The method of formatting the disk comprises identifying a first quantity of the storage portions; and labeling the first quantity of storage portions as non-addressable storage portions such that the non-addressable storage portions cannot be accessed by a user or a disk drive. The first quantity of storage portions may include addressable portions designated as non-addressable portions.

Abstract: A process for identifying and designating a radially-oriented defect pattern on a data-storage medium comprises determining an angular position of one or more pre-identified defective data sectors on the data-storage medium by counting a number of servo sectors on the data-storage medium that pass a predetermined reference point. The process also comprises defining a radially-oriented pattern of the pre-identified defective data sectors based on a predetermined relationship between: a number of the pre-identified defective data sectors having substantially identical angular positions; and radial spacing between the pre-identified defective data sectors having substantially identical angular positions. The process further comprises writing defect-identification information to data sectors having locations that substantially coincide with the radially-oriented pattern of the pre-identified defective data sectors.

Abstract: A defect map for a data-storage medium is generated without the use of a hard index on the medium. The servo sectors normally written to the medium during formatting operations are utilized to identify the angular positions of defective data sectors. The track-location data typically stored in each data sector is used to identify the radial positions of defective sectors. This positional information is processed by a set of computer-executable instructions that generate a graphical representation of the data-storage medium. Symbols are placed on the graphical representation in positions corresponding to the locations on the medium at which defective data sectors are identified.

Abstract: Methods are provided for preventing data from being written to a data sector that has been identified as faulty on a disk in a disk drive system. It is first determined whether data of a data sector of a portion of a disk is recoverable. If the data is non-recoverable, an invalid logical ID is written to the logical block address (LBA) corresponding to the data sector thereby identifying the data sector as faulty and preventing data from being written at the data sector. The LBA is then reallocated to point to a different data sector if the data is non-recoverable. Thus, further data directed to the LBA will be written to the different data sector responsive to the reallocated LBA, thereby avoiding writing the new data to the data sector identified as faulty. Internal drive read re-tries can still take place on the faulty data sector even after the LBA has been assigned an invalid logical ID.

Abstract: A disk is manufactured having a reduced capacity based on a quantity of addressable and non-addressable portions. The method of formatting the disk comprises identifying a first quantity of the storage portions; and labeling the first quantity of storage portions as non-addressable storage portions such that the non-addressable storage portions cannot be accessed by a user or a disk drive. The first quantity of storage portions may include addressable portions designated as non-addressable portions.

Abstract: An information storage device (10, 510, 610, 710, 810) includes a cradle (12, 512, 612, 712, 812) which can removably receive a cartridge (11, 411, 511, 611, 711) that contains a rotatable hard disk (91, 326-327). A read/write head (107, 331-334) is supported for movement adjacent the disk by a pivotal actuator arm (101). The cradle controls alignment of the head with the disk using feedback servo tracking. Calibration parameters used to perform this tracking, such as servo information or read channel information, may be stored in a special track (414) which is on the disk, and which may be a read-only track. The special track stores a plurality of sets of calibration parameters, each corresponding to a respective combination of a cradle and an environmental characteristic such as temperature.