Abstract: An adjacent track interference (ATI) metric is determined for each of a plurality of regions of a single surface of a magnetic disk. Based on the ATI metrics, each of the regions is assigned a region-specific directed offline scan (DOS) criterion, at least two of the DOS criteria being different from one another. Based on a write count of a track within one of the regions satisfying the associated region-specific DOS criterion, a DOS remediation of the track is performed.

Abstract: An adjacent track interference (ATI) metric is determined for each of a plurality of regions of a single surface of a magnetic disk. Based on the ATI metrics, each of the regions is assigned a region-specific directed offline scan (DOS) criterion, at least two of the DOS criteria being different from one another. Based on a write count of a track within one of the regions satisfying the associated region-specific DOS criterion, a DOS remediation of the track is performed.

Abstract: A method for testing and grading electronic devices includes receiving a set of testing data associated with an electronic device that is following a testing routine. Based on the set of testing data, the method includes computing a first performance metric of the electronic device by using a first artificial neural network and computing a second performance metric of the electronic device by using a second artificial neural network. Based on at least the first predicted performance metric and the second predicted performance metric, the method includes computing a grade for the electronic device.

Abstract: A method for testing and grading electronic devices includes receiving a set of testing data associated with an electronic device that is following a testing routine. Based on the set of testing data, the method includes computing a first performance metric of the electronic device by using a first artificial neural network and computing a second performance metric of the electronic device by using a second artificial neural network. Based on at least the first predicted performance metric and the second predicted performance metric, the method includes computing a grade for the electronic device.

Abstract: A method is disclosed for establishing a fly height parameter for a hard disc drive. The method includes receiving a set of testing data associated with the hard disc drive and subjecting the hard disc drive to a fly-height test at a first, nominal temperature to generate fly-height data. Based on the set of testing data and the fly-height data, the method includes predicting the hard disc drive's fly-height data for a fly-height test at a second temperature different from the first, nominal temperature. The method further includes establishing the fly-height parameter for the hard disc drive in response to the fly-height data and the predicted fly-height data.

Abstract: A method for performing a flaw scan test on a hard disk drive is disclosed. The hard disk drive includes a magnetic recording medium and spindle motor associated with a predetermined rated speed. The method includes writing a test pattern to the magnetic recording medium while operating the spindle motor at a speed greater than the predetermined rated speed. The method also includes reading the test pattern at the greater speed and detecting flaws in response to reading the test pattern.

Abstract: Method and apparatus for positioning shingled magnetic recording (SMR) tracks on a rotatable data storage medium. In some embodiments, a first band of partially overlapping tracks is written the medium at a first track pitch. An adjacent, second band of partially overlapping tracks is written to the medium at the first track pitch. The second band has a first written track at a second track pitch with respect to a last written track in the first band. The second track pitch is determined in response to an error rate established for a test track using an adjacent track written at the first track pitch.

Abstract: A data storage device can be tested while spinning at a variety of different speeds. Data may be written to a data sector with a transducing head while at least one disk of a data storage device spins about a spindle at a default speed. One or more tests can subsequently be executed on the disk by reading servo data stored on the disk while the disk spins at a test speed that is greater than the default speed.

Abstract: An apparatus and method for selecting physical cylinders (cylinders accessible for read/write operations) in a disc drive is provided. The disc drive includes at least one rotatable disc. The disc drive also includes a first head, which is positionable adjacent a first disc surface, and a second head, which is positionable adjacent a second disc surface. The first disc surface has a first plurality of greycode tracks and the second disc surface has a second plurality of greycode tracks. Each greycode track of the second plurality of greycode tracks corresponds to a different greycode track of the first plurality of greycode tracks, thereby forming a plurality of greycode cylinders, with each greycode cylinder of the plurality of greycode cylinders including a pair of corresponding greycode tracks. The physical cylinders are a subset (less than all) of the plurality of the greycode cylinders.

Abstract: Data on a storage medium are refreshed by reading the data from a first location on the storage medium, storing them to a second location, and reading the data from the second location and storing them at the first location. The first and second locations are first and second physical locations and a logical address is initially associated with the first physical location. When the data are stored at the second location, the association of the logical address is changed to the second physical location. When the data are stored again at the first location, the association of the logical address is changed to the first physical address. The process is performed iteratively on the basis of successive logical block addresses. If the storing the data at the first location is interrupted, the data is re-read from the second location, and re-stored to the first location.

Abstract: A logical-to-physical head map is built upon each power up of a disc drive. After powering the controller and disc drive spindle motor, a bias current is iteratively supplied to the read heads in succession. A representation of the voltage across each read head is stored in a fault register for comparison to a threshold and a “good” or “bad” fault status is stored for each head. A logical-to-physical head map is defined based on the number of logical heads, which in turn is based on the disc drive serial number. Each of the logical heads in the logical-to-physical head map is associated to a respective one of the heads having a “good” fault status to construct the logical-to-physical head map in the controller memory.

Abstract: A method sets bit densities and track densities for a plurality of heads in a data storage device. The method includes determining an initial bit density and an initial track density for each head. An initial total capacity for the storage device is determined based on the initial track densities and the initial bit densities. A desired capacity for the storage device is selected and the initial total capacity and the desired capacity are compared. One of either a bit density or a track density is then adjusted so that the data storage device has an adjusted capacity that provides some excess capacity over the desired capacity where the excess capacity is less than any excess capacity that was present between the initial capacity and the desired capacity. A data storage device formed through this method is also provided.

Abstract: The present invention pertains to an apparatus and method for recording data in a variable bit density disc drive. The disc drive includes a recording surfaces, each having a corresponding head for recording data on the recording surface. At least one head is operated at a different recording frequency from the other heads, creating a variable bit density for the different recording surfaces. The combination of head recording frequencies is determined following an error testing operation and a unique physdisc lookup table is created based on the determined recording frequencies. The physdisc lookup table is used to allocate data sectors and to convert between logical and physical block addresses.

Abstract: A method of, system, modules, and computer readable media for generating a defect error log on a disc in a disc drive is disclosed. All defective sector addresses of all defective sectors on the disc are identified and stored in the memory. At least two defective sectors identified are adjacent to each other circumferentially or radially or in both directions. The at least two sector addresses of adjacent defective sectors are merged into a defect error entry. Merging refers to a conversion (or encoding) of the multi sector addresses into a defect error entry. The converted defect error entry is then stored in the defect error log.

Abstract: The present invention pertains to an apparatus and method for recording data in a variable bit density disc drive. The disc drive includes a recording surfaces, each having a corresponding head for recording data on the recording surface. At least one head is operated at a different recording frequency from the other heads, creating a variable bit density for the different recording surfaces. The combination of head recording frequencies is determined following an error testing operation and a unique physdisc lookup table is created based on the determined recording frequencies. The physdisc lookup table is used to allocate data sectors and to convert between logical and physical block addresses.

Abstract: A disc drive production process automatically configures the disc drive to a suitable capacity based upon the data transfer capability of each of the head/disc surface combinations in the drive. The error rate of each of the head/disc surface combinations is determined as a function of the bit density of the disc surface. Based on the data transfer capability of the head/disc surface combinations, one of three drive configuration schemes is selected. A variable BPI (bits per inch) scheme reduces the data rate of a weak head/disc surface combination while increasing the data rate of a strong head/disc surface combination. If the drive contains one very weak head/disc surface combination, a head depopulation scheme disables the very weak head. If the drive contains two or more very weak heads, a de-frequency scheme reduces the overall capacity of the drive.

Abstract: The present invention pertains to an apparatus and method for recording data in a data storage medium. The data storage medium includes a number of discs, each having at least one recording surface. Each recording surface is associated with a read/write head that records and accesses data from the surface. Each recording surface is partitioned into a number of zones. Each zone is vertically aligned with a same zone on each surface of each disc. The zone boundaries on all surfaces of the disc drive are the same. The recording frequency for each zone on all surfaces can differ for each read/write head in order to compensate for a read/write head that cannot meet the BPI error rate threshold.

Abstract: A method sets bit densities and track densities for a plurality of heads in a data storage device. The method includes determining an initial bit density and an initial track density for each head. An initial total capacity for the storage device is determined based on the initial track densities and the initial bit densities. A desired capacity for the storage device is selected and the initial total capacity and the desired capacity are compared. One of either a bit density or a track density is then adjusted so that the data storage device has an adjusted capacity that provides some excess capacity over the desired capacity where the excess capacity is less than any excess capacity that was present between the initial capacity and the desired capacity. A data storage device formed through this method is also provided.

Abstract: The present invention pertains to an apparatus and method for recording data in a data storage medium. The data storage medium includes a number of discs, each having at least one recording surface. Each recording surface is associated with a read/write head that records and accesses data from the surface. Each recording surface is partitioned into a number of zones. Each zone is vertically aligned with a same zone on each surface of each disc. The zone boundaries on all surfaces of the disc drive are the same. The recording frequency for each zone on all surfaces can differ for each read/write head in order to compensate for a read/write head that cannot meet the BPI error rate threshold.