Abstract: The present invention may be embodied in a method and a disk drive for improving head position accuracy during track following through real-time identification of external vibration. A selected track is followed using a servo control loop having a nominal gain and being responsive to position error signal samples generated based on a difference between head position samples and a reference head position value. A spectral power value within a predetermined frequency band is determined from a sequence of the position error signal samples. If a property of the spectral power value exceeds a threshold, the gain of the servo control loop is increased within the predetermined frequency band to attenuate the effect of external vibration on the position of the head over the selected track during track following.

Abstract: A communication channel is disclosed comprising a trellis sequence detector for detecting an estimated data sequence from signal sample values. A post processor detects and corrects an error event of the trellis sequence detector by remodulating the estimated data sequence into a sequence of expected sample values, computing samples errors as the difference between the expected samples and signal samples, and correlating the sample errors with error event samples. The communication channel further comprises a Reed-Solomon error correction code (ECC) decoder for decoding a Reed-Solomon codeword in the estimated data sequence in response to the detected error event.

Abstract: A disk drive includes an enclosure that defines an exterior surface, the enclosure including a base, a cover and a hinge mechanically coupling the base to the cover such that the hinge forms a portion of the exterior surface of the enclosure. A spindle motor is attached to the base, a disk is mounted to the spindle motor, and a head stack assembly is pivotally coupled to the base. A method of manufacturing a disk drive includes a single (injection, for example) molding step to form an enclosure including the base, the cover and a hinge that mechanically couples the base to the cover such that the hinge forms a portion of the exterior surface of the enclosure. The spindle motor may then be attached to the base, the disk or disks mounted to the spindle motor and the head stack assembly may be pivotally coupled to the base.

Abstract: A preamplifier circuit is disclosed comprising a data input for receiving write data, a read signal output for outputting an amplified read signal, a read signal input for receiving a read signal from a read element, and a write signal output for supplying a write signal to a write element. The preamplifier circuit further comprises a first amplifier circuit, responsive to the write data, for generating the write signal supplied to the write element, and a second amplifier circuit for amplifying the read signal from the read element to generate the amplified read signal output via the read signal output. A head control circuit, responsive to head select data, simultaneously enables the first and second amplifier circuits to perform a simultaneous read and write operation.

Abstract: An air bearing slider for use in a disk drive that includes a rotatable magnetic disk. The slider includes a leading side and a trailing side. The slider further includes a pressurized pad including a pressurized pad air bearing surface. The pressurized pad is disposed between the leading and trailing sides. The slider further includes a contact pad disposed adjacent the trailing side and including a contact surface for sliding contact with the magnetic disk during operation of the disk drive. The contact pad includes a transducer disposed within the contact pad for reading and writing data from and to the magnetic disk. The slider further includes a depressed region disposed between the pressurized pad and the contact pad for mitigating air pressure adjacent the contact surface relative to air pressure adjacent the pressurized pad air bearing surface during operation of the disk drive.

Abstract: A network switch is disclosed for resolving requests from a plurality of host initiators by scheduling access to a plurality of storage systems. The network switch comprises a plurality of multi-port switches interconnected to form a switched fabric, the multi-port switches for routing requests to the plurality of storage systems and for receiving scheduling data from each of the plurality of storage systems. The network switch further comprises a memory for storing the scheduling data, and a microprocessor, responsive to the scheduling data stored in the memory, for executing a scheduling algorithm to schedule the requests. The scheduling data is transferred automatically from each storage system to the memory through the multi-port switches without the microprocessor requesting the scheduling data from each storage system.

Abstract: A method of operating an audiovisual disk drive having a default audiovisual mode for more efficiently transferring audiovisual data from or to a host pursuant to audiovisual host commands. The innovative method includes the steps of receiving a new transfer command requiring the transfer of a data segment associated with the audiovisual data stream; determining an absence or presence of an urgent condition with regard to the new transfer command; according standard precedence to processing the audiovisual data stream associated with the new transfer command as specified by the default operating mode in the determined absence of the urgent condition; and according urgent precedence to processing the audiovisual data stream associated with the new transfer command over attending to the other drive operation in the determined presence of the urgent condition without regard to the default operating mode.

Abstract: A computer system having a host computer is connected to a disk drive for providing a key to enable a feature controlled by the disk drive. The disk drive validates the key using private validation means which are accessed by a disk drive microprocessor. The validation means include drive-dependent identification means which are used to derive a seed for generating an internal key to validate the key provided by the host computer. An exemplary feature enabled by the key validation is an expansion area of the disk drive which is enabled to provide extended user data storage without requiring internal physical access by the user.

Abstract: The invention may be embodied in a method and a related computer system. The computer system includes a host computer with a native drive-access routine having a limited address range, and a disk drive with a protected area that is inaccessible to a user's preferred operating system. The protected area also lies beyond the limited address range. The method includes receiving and detecting a command in the disk drive for reading a master boot record to initiate a bootload of the operating system. In response to detecting the command, the method includes transferring a drive-selected master boot record that, when executed in the computer system, initiates a process that enables address spoofing, loads an extended-address drive-access routine from the protected area using spoofed addresses within the limited address range, and executes the extended-address drive-access routine to replace the native drive-access routine for providing access to the protected area.

Abstract: An aspect of the invention can be regarded as a disk drive that includes a disk drive base and a spindle motor hub. The disk drive includes a disk disposed about the spindle motor hub and including a disk surface. The disk drive includes a plurality of fasteners. The disk drive includes a disk clamp attached to the spindle motor hub in mechanical communication with the disk surface for securing the disk. The disk clamp includes a plurality of engaged fastener holes formed through the disk clamp and non-symmetrically distributed about an axis of rotation. The fasteners are engaged within the engaged fastener holes for attachment of the disk clamp and the disk to the spindle motor hub. According to another aspect of the present invention, fasteners are non-uniformly torqued within fastener openings for applying a non-symmetric clamping force by the disk clamp against the disk.

Abstract: A disk drive is disclosed comprising a disk, a head, an actuator arm for actuating the head radially over the disk, a fixed object, and a voice coil motor (VCM) for rotating the actuator arm about a pivot, the VCM comprising a coil comprising a VCM resistance R. A back EMF voltage detector measures a back EMF voltage across the coil, and a current detector detects a current I flowing through the coil. An IR voltage detector, responsive to the current I detected by the current detector, detects an IR voltage proportional to the current I times the VCM resistance R. A voltage compensator substantially cancels the IR voltage from the measured back EMF voltage to generate a compensated back EMF voltage. A control voltage generator, responsive the compensated back EMF voltage, generates a control voltage applied to the coil to generate the current I flowing through the coil.

Abstract: The present invention relates a method for accelerated scanning of a disk drive for media damage caused by rough handling. In the method, a current cylinder number is set to an initial target cylinder number. Data is read from a track associated with the current cylinder number and is checked for an error indicative of media damage. The current cylinder number is then set to a next target cylinder number that is equal to the current cylinder number plus a cylinder skip factor. The skip factor causes the current cylinder number to change by more than one cylinder number. For the new current cylinder number, the reading and checking steps are repeated. Unlike a full media scan that attempts to read all of the tracks of a disk drive, the accelerated media scan method of the invention skips tracks by skipping cylinder numbers to reduce the scan time while maintaining a great deal of certainty that media damage is detected.

Abstract: A method of writing servo tracks on the disk surfaces of a hard disk drive. The method involves simultaneously writing partial servo tracks, called servo wedges, until a complete first set of servo wedges is written on all the disk surfaces. Then the disks are rotated until the heads of the disk drive are correctly positioned to simultaneously write subsequent servo wedge sets. This process is repeated until enough servo wedge sets are written to complete a first servo track on all the disk surfaces. Then, the heads are pivoted to a new radial position to begin writing a new servo track just as before. Simultaneously writing servo wedges advantageously expedites the often costly servo writing process.

Abstract: Disclosed herein is a disk drive that includes a housing including a base, the base defining a blind receptacle, a spindle motor attached to the base, a disk mounted to the spindle motor and a head stack assembly pivotally coupled to the base. The head stack assembly includes a body portion including a first bore defining a pivot axis, an actuator arm cantilevered from the body portion, and a head gimbal assembly supported at the actuator arm and including a head. The base defines a blind receptacle and the actuator arm defines a second bore that is situated so as to enable the second bore and the blind receptacle to align along an axis parallel to the pivot axis when the head stack assembly is pivoted such that the head is not over the disk.

Abstract: A disk drive is disclosed comprising a disk, a head, and an actuator for actuating the head radially over the disk. The disk comprises a plurality of tracks, wherein each track comprises a plurality of sectors. The plurality of sectors comprise a plurality of data sectors for storing data and at least one sector-reconstruction (SR) sector for storing redundancy data generated in response to the data stored in at least one of the data sectors. At least two of the plurality of sectors of a track are for storing a SR status indicating a validity of the SR sector stored on the track.

Abstract: The present invention may be regarded as a disk drive comprising a disk having a plurality of data tracks and at least one reserved track. At least one of the data tracks for recording user data along a circumferential path offset from the centerline of the data track, and the at least one reserved track for recording data track micro-jog values along a circumferential path substantially aligned with the centerline of the reserved track.

Abstract: A disk drive that includes a base, a magnetic disk, a rotary actuator that carries a head for reading and writing data from the disk in a track-following mode under the control of a servo control system, and at least two sensors—one fixed sensor rigidly coupled to the overall disk drive and one mobile sensor mounted to the rotating actuator—for differentially detecting accelerations of the rotary actuator relative to the overall disk drive and its disk. The disk drive detects and actively compensates for accelerations imparted to a balanced actuator that has an effective imbalance. The fixed sensor is preferably mounted to a PCBA that is secured to the base. The mobile sensor is preferably mounted to an actuator arm of the rotary actuator, as far outboard as possible, and so as to align with the fixed sensor as the rotary actuator swings through its range of travel. The preferred sensors are linear accelerometers.

Abstract: The invention is directed to a method and associated device for storing stream and non-streaming data in common memory space of a data storage device. The method includes steps of organizing addressable locations of a data storage in a logical sequence, and initially storing streaming data by accessing the logical sequence of addressable locations in a first direction, and for storing non-streaming data by accessing the logical sequence of addressable locations in a second direction which is opposite the first direction.

Abstract: The invention may be embodied in a disk drive for use in a mobile device. The mobile device may be a hand held computing device such as a personal digital assistant (PDA) or a mobile terminal such as a cellular telephone. The mobile device includes a host processor for accessing data on the disk drive. The disk drive has a rotating disk media and a moveable read/write head disposed over the disk media. The disk media is divided into a first data storage zone and a second data storage zone. The data storage zones are radially disposed in discrete areas of the disk media and each zone has a plurality of tracks for storing data. The mobile device may write data to the first data storage zone when the mobile device is in a mobile environment. The mobile device may write data to the second data storage zone only when the mobile device is in a non-mobile environment and may not write data to the second data storage zone when the mobile device is in a mobile environment.

Abstract: A disk drive includes a disk drive base and a cover including a cover outer surface and a fastener opening disposed through the cover. The disk drive further includes an electrically insulative coating disposed upon the cover outer surface. The disk drive further includes a fastener that includes a fastener head and a fastener shaft. The disk drive further includes a fastener support disposed adjacent to the fastener opening. The fastener support includes a top surface for engaging the fastener head. The fastener support includes a central opening sized and configured to receive the fastener shaft through the central opening for mechanically coupling the cover and the disk drive base. The disk drive further includes a conductive path disposed between the disk drive base and the cover. The conductive path includes the fastener and the fastener support.