Abstract: A data storage device can employ one or more transducing heads that have a data reader and data writer each connected to a substrate of the transducing head. The substrate can be electrified with a predetermined surface charge by a charge circuit of the transducing head to maintain, or alter, a head-media spacing.

Abstract: A data reader may have a magnetoresistive stack with a magnetically free layer decoupled from a first shield by a cap. The cap can have one or more sub-layers respectively configured with a thickness of 4 nm or less as measured parallel to a longitudinal axis of the magnetoresistive stack on an air bearing surface.

Abstract: Bottom tracks are written to a recording medium using a first setting of a microwave assisted magnetic recording (MAMR) head. Top tracks are interlaced between and partially overlapping the bottom tracks using a second setting of the MAMR head, the second setting resulting in a narrower track width than the first setting.

Abstract: A method for using a variable-size flash translation layer. The method includes reading an entry in a map based on a read logical block address in a read request to obtain both a physical address of a particular page in a memory and information regarding compressed data with a variable size; converting the information to both an address in the particular page and a number of read units in the memory that contain the compressed data; and reading the compressed data from at least the particular page in the memory based on the address and the number of read units.

Abstract: A directional control valve comprising: a body, an actuator configured to switch the directional control valve between two or more states, a manual activation button configured to initiate actuation of the actuator when pressed, a safety member configured to slide along a guide of the body between a first position and a second position, a coupling member configured to couple the directional control valve to other directional control valves, and a guard removably disposed between the safety member and the coupling member. The safety member prevents the manual actuation button from being actuated when it is in the first position and the manual actuation button can be manually actuated when the safety member is in the second position. In addition, the guard is configured to prevent the safety member from sliding to the second position when the guard is disposed between the safety member and the coupling member.

Abstract: An apparatus includes a memory and a controller. The memory may be configured to store data. The controller may have a host interface circuit connectable to a host. The controller may be configured to process a plurality of input/output requests to read/write to/from the memory, compute a first bandwidth consumed by the controller while servicing the memory with one or more tasks hidden from the host, compute a second bandwidth of the memory that is available to the host through the host interface circuit based on the first bandwidth consumed by the controller, receive a hypothetical consumption of additional bandwidth by the host, update the second bandwidth based on the hypothetical consumption, and report the second bandwidth as updated to the host through the host interface circuit.

Abstract: Methods and apparatus are provided for adaptive read threshold voltage tracking with separate characterization on each side of a voltage distribution about a distribution mean. A read threshold voltage for a memory is adjusted by determining statistical characteristics of two adjacent memory levels based at least in part on a type of statistical distribution of the memory levels and a distribution of data values read from cells using a plurality of read threshold voltages, wherein the statistical characteristics of the two adjacent memory levels are characterized independently on two sides about at least one mean of the statistical distribution; computing an adjusted read threshold voltage associated with the two adjacent memory levels by using the statistical characteristics of the two adjacent memory levels; and updating the read threshold voltage based on the adjusted read threshold voltage. The adjustment is optionally performed responsive to one or more read errors.

Abstract: Pseudorandom bit sequences are recorded to a heat-assisted recording medium at a laser power that is stepped while recording the pseudorandom bit sequences. The pseudorandom bit sequences are read from the heat-assisted recording medium to determine timing differences between bits written before and after the laser power is stepped. A thermal gradient of bits written to the heat-assisted recording medium is determined based on the timing differences.

Abstract: Systems and methods for calculating random values based on data errors are presented. A message collection circuit may collect sets of data having data errors and store them to a memory. The stored sets of data may then be processed to produce a random value based on errors in the sets of data. The random value(s) may be provided to random number generator(s), encryption circuit(s), or other circuit(s).

Abstract: Apparatus and method for data security in a data storage device. In some embodiments, an alternating pattern is written to a magnetic recording medium as a sequence of symbols at a selected clock rate. A repeatable magnetic signature is generated by reading the alternating pattern from the medium, the magnetic signature having relatively weak entropy at boundaries of the symbols. A multi-bit digital sequence is extracted from the repeatable magnetic signature, the digital sequence having relatively strong entropy. The digital sequence is stored in a separate memory coupled to the medium. Access to data stored on the medium is authenticated responsive to the digital sequence stored in the separate memory.

Abstract: A method involves determining bit aspect ratios for interlaced tracks written to a magnetic recording medium. The interlaced tracks include top tracks that are written partially overlapping with bottom tracks. Isolated test tracks are written at first different bit aspect ratios to determine a top bit aspect ratio that achieves a first target areal density for the isolated test tracks. Test tracks are written at second different bit aspect ratios to determine a bottom bit aspect ratio that achieves a second target areal density for the test tracks. Top test tracks of the test tracks are written at the top bit aspect ratio. The top and bottom bit aspect ratios are selected to subsequently write partially-overlapping tracks on the magnetic recording medium.

Abstract: A method includes receiving a first set of testing data associated with a first group of electronic devices. The first set of testing data is generated during a tuning test applying a first range of testing parameters. The method further includes receiving a second set of testing data associated with the first group of electronic devices. Further, the method includes determining, based on the first set of testing data and the second set of testing data, a second range of testing parameters that is less than the first range of testing parameters. The method includes testing a second group of electronic devices using a tuning test applying the second range of testing parameters.

Abstract: A first input is processed via a first configuration of a neural network to produce a first output. The first configuration defines attributes of the neural network, such as connections between neural elements of the neural network. If the neural network requires a context switch to process a second input, a second configuration is applied to the neural network to change the attributes, and the second input is processed via the second configuration of the neural network to produce a second output.

Abstract: A servo sector on a disk is read via first and second readers that both span two or more user data tracks. The servo sector has a crosstrack width that spans the two or more user data tracks. The first reader provides a first signal based on detecting a total longitudinal field of the servo sector. The second reader provides a second signal based on detecting a total perpendicular field of the servo sector. A position error of the first and second readers is detected using. A value of the first signal can be used to detect a position error, detect a track-to-track phase error, and/or detect a Gray code error of a track ID field of the servo sector.

Abstract: A first reader spans first and second tracks of a recording medium and provides a first signal responsive to a first total longitudinal field of the first and second tracks. A second read spans two other tracks, at least one of the two other tracks being different from the first and second tracks. The second reader provides a second signal responsive to a second total longitudinal field of the two other tracks. A third reader spans two or more of the tracks and provides a third signal responsive to a total perpendicular field of the two or more tracks. User data is decoded from the first, second, and third signals.

Abstract: A node includes a controller that includes one or more processors. The controller may be configured to load data from a storage data block of a plurality of storage data blocks stored on one or more first data storage devices to a working data block stored on one or more second data storage devices. In response to a node experiencing a failure, the controller can be configured to determine a change value for the working data block. The controller can be configured to determine whether data stored in the working data block is different than data stored in the corresponding storage data block based on the determined change value and a provided change value that corresponds to the storage data block.

Abstract: A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.

Abstract: Methods, apparatuses, and systems for fluid connections in modular cooling systems for cooling electronic components installed in equipment racks. A cold plate is positioned adjacent to a support manifold in a mated position, where the cold plate comprises a plate connector. The plate connector comprises a plate outer sleeve and defines a central passageway. The support manifold comprises a manifold connector, which comprises a manifold outer sleeve and defines a central passageway. An outer surface of the manifold outer sleeve is positioned adjacent to an outer surface of the plate outer sleeve. A cam is rotated about a pivot pin and engages with a plate retainer to secure the cold plate against the support manifold, and the central passageway of the plate connector is connected in fluid communication with the central passageway of the manifold connector.

Abstract: Systems and methods are disclosed for wear-based access optimization. An apparatus may comprise a circuit configured to perform a data access operation at a target location of a memory, and determine a wear value of the target location. The circuit may compare the wear value to global wear value of other locations of the drive, and adjust data access parameters for the target location based on the comparison.

Abstract: A method of forming a recording head for use with a data storage medium in a data storage device. The method includes forming first and second writers of different target geometries. A first recording measurement is performed on one or more storage media using the first writer. A second recording measurement is performed on the one or more storage media using the second writer. Based on a comparison of the first and second recording measurements to a predetermined quantity, either the first writer or the second writer is selected to be operational in the data storage device.