A controller extracts a distortion component of a readback signal from a magnetic read head. The distortion component may be found using a finite length Volterra series, for example. The controller estimates a clearance between the read head and a recording medium based on the distortion component. This clearance measurement can be used for closed loop fly-height control of the read head.

A dual disk spindle motor hard disk drive includes a first portion having a first spindle motor and a first disk media stack mounted thereon and housed in a first enclosure, and a second portion having a coaxial second spindle motor and a second disk media stack mounted thereon and housed in a second enclosure, where the second portion further includes both the first actuator and head sliders corresponding to the first disk stack as well as the second actuator and head sliders corresponding to the second disk stack. The first and second portions are coupled together such that the open sides of the enclosures mate, referred to herein as a clamshell configuration, and each separate spindle motor is configured to operate independently of the other. With independent control of multiple spindle motors, various control functions may be utilized to address power consumption and temperature control.

A dual disk spindle motor hard disk drive includes a first portion having a first spindle motor and a first disk media stack mounted thereon and housed in a first enclosure, and a second portion having a coaxial second spindle motor and a second disk media stack mounted thereon and housed in a second enclosure, where the second portion further includes both the first actuator and head sliders corresponding to the first disk stack as well as the second actuator and head sliders corresponding to the second disk stack. The first and second portions are coupled together such that the open sides of the enclosures mate, referred to herein as a clamshell configuration, and each separate spindle motor is configured to operate independently of the other. With independent control of multiple spindle motors, various control functions may be utilized to address power consumption and temperature control.

A circuit includes a set of input nodes configured to be coupled to respective ones of the windings of a spindle motor in a hard disk drive to sense the voltages applied to the windings. A set of output nodes is configured to provide output signals indicative of direction of flow of the currents through the windings. Level shifters are coupled to respective input nodes in the set of input nodes and have level-shifted output nodes configured to provide down-shifted replicas of the voltages at the respective input nodes in the set of input nodes. Flip-flops have inputs coupled to respective ones of the level-shifted output nodes of the level shifters and outputs configured to provide the output signals coupled to respective output nodes.

A data storage device is disclosed comprising a head actuated over a disk. A plurality of access commands are stored in a command queue, wherein the access commands are for accessing the disk using the head. A future access command is predicted, and an execution order for the access commands in the command queue is determined based on an associated execution cost of at least some of the access commands in the command queue and an associated execution cost of the future access command. At least one of the access commands in the command queue is executed based on the execution order.

A data storage device is disclosed comprising a head actuated over a disk. A plurality of access commands are stored in a command queue, wherein the access commands are for accessing the disk using the head. A future access command is predicted, and an execution order for the access commands in the command queue is determined based on an associated execution cost of at least some of the access commands in the command queue and an associated execution cost of the future access command. At least one of the access commands in the command queue is executed based on the execution order.

A hard disk drive (HDD) includes a suspension connected to a stack arm. The suspension includes a mount plate, a hinge, a load beam, and a circuit. The mount plate includes a bottom surface facing a disk and an ear portion extending from a side edge of the mount plate. The bottom surface includes a planar region, a first indented region vertically recessed relative to the planar region, and a second indented region located at the ear portion and vertically recessed relative to the planar region. The load beam terminates in a load beam hinge is connected to the first indented region. The circuit extends along the first and second indented regions.

According to one embodiment, a magnetic disk device comprises a feedforward control unit, which includes a plant model processing unit including a plurality of submodel processing units. Each of the submodel processing units generates a submodel output value that is an output value for an input value to be input, and the feedforward control unit generates the output value based on a plurality of the submodel output values.

According to one embodiment, a magnetic disk device comprises a feedforward control unit, which includes a plant model processing unit including a plurality of submodel processing units. Each of the submodel processing units generates a submodel output value that is an output value for an input value to be input, and the feedforward control unit generates the output value based on a plurality of the submodel output values.

Provided is a magnetic tape, in which servo patterns, each including a first magnetization region formed to be tilted with respect to a width direction of a servo band by an angle ? along the width direction of the servo band and a second magnetization region not parallel to the first magnetization region along the width direction of the servo band, are repeatedly formed in a longitudinal direction of the servo band, the magnetic tape is used in a recording and reproducing system which uses a reproducing element for reproducing the servo pattern, a width of which satisfies W1?(1/tan ?)?stripe width T of the servo pattern, and the angle ? is greater than 25? and equal to or smaller than 45?.