Abstract: The technology disclosed herein provides a method for generating an on-cylinder limit (OCLIM), the method including performing servo certification of a plurality of drives in a storage device to generate servo adaptive parameters (SAPs) by heads, generating a plurality of read adjust parameters (RAPs) by heads for the plurality of drives, generating an interim OCLIM value based on the SAPs by heads and RAPs by zones, and operating a disc drive write element using the interim OCLIM value.

Abstract: The technology disclosed herein provides a method for generating an on-cylinder limit (OCLIM), the method including performing servo certification of a plurality of drives in a storage device to generate servo adaptive parameters (SAPs) by heads, generating a plurality of read adjust parameters (RAPs) by heads for the plurality of drives, generating an interim OCLIM value based on the SAPs by heads and RAPs by zones, and operating a disc drive write element using the interim OCLIM value.

Abstract: A hard disk drive includes a magnetic writer and a magnetic recording medium, which includes data tracks with user data sections positioned between servo wedges. The servo wedges each can include multiple servo sectors. The hard disk drive also includes circuitry programmed to cause the magnetic writer to write user data to the multiple servo sectors in multiple servo wedges.

Abstract: The technology disclosed herein provides a method for generating an on-cylinder limit (OCLIM), the method including performing servo certification of a plurality of drives in a storage device to generate servo adaptive parameters (SAPs) by heads, generating a plurality of read adjust parameters (RAPs) by heads for the plurality of drives, generating an interim OCLIM value based on the SAPs by heads and RAPs by zones, and operating a disc drive write element using the interim OCLIM value.

Abstract: Method and apparatus for recovering user data from a rotatable data recording medium. In some embodiments, a moveable read element detects at least one uncorrectable read error in user data stored in a data sector arranged along a concentric track. A read retry operation is carried out to recover the user data by radially advancing the moveable read element from a first offset value to a different second offset value with respect to the track in accordance with a trajectory profile while transducing the user data from the data sector. This allows data that are variably overwritten (encroached upon) by different radial amounts from an adjacent track to be recovered.

Abstract: Systems and methods are disclosed for using track misregistration values, representing an amount of off-track deviation of a write element, to dynamically increment error scan counters for proximate storage areas. In certain embodiments, an apparatus may comprise a processor configured to perform a write operation to record data to a target track of a data storage medium using a write element, determine an amount of deviation of the write element from a center line of the target track, and increment an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

Abstract: An adaptive guard band scheme is disclosed for a data storage device. In illustrated embodiments, the adaptive guard band scheme formats different guard band cylinders and track zeros for different heads depending upon a contact cylinder of the different heads. In an illustrative embodiment, the adaptive guard band scheme utilizes the contact cylinders for the heads and a no fly cylinder to determine track zero(s) and extended data zone(s) for select heads.

Abstract: Systems and methods are disclosed for writable servo zone overlap regions on a disc memory. An apparatus may comprise a controller configured to determine a servo gate (sgate) timing for an overlap zone including servo patterns of a first servo super zone and a second servo super zone of a disc memory, the sgate timing based on servo pattern timing for the first servo super zone and the second servo super zone. The controller may initiate writing to the overlap zone based on the sgate timing. The controller may also reduce the impact of servo pattern frequency change between zones by calculating a trajectory error prior to the crossing, and providing 1/X of the trajectory error into a servo feedback loop for a following X servo sampling points.

Abstract: An adaptive guard band scheme is disclosed for a data storage device. In illustrated embodiments, the adaptive guard band scheme formats different guard band cylinders and track zeros for different heads depending upon a contact cylinder of the different heads. In an illustrative embodiment, the adaptive guard band scheme utilizes the contact cylinders for the heads and a no fly cylinder to determine track zero(s) and extended data zone(s) for select heads.