Abstract: The present invention provides a disk drive, a load/unload unit, and a control method thereof which are capable of reliably unloading a head slider from a disk when power is turned off and enhancing reliability. A disk drive is equipped with a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving over the surface of the magnetic disk or to an evacuating position a head slider having the magnetic head, a ramp block, and a CPU/HDC (control means) for performing control of load and unload operations, speed control of the actuator mechanism, and control of an operation of reading or writing data from or to the disk. The CPU/HDC receives a specific command issued from the host immediately before power is turned off, and executes this command, then executes unload control, and notifies the host of command completion after the unload control has been completed.

Abstract: The present invention provides an actuator locking mechanism which is structurally simple and has a strong locking force. The actuator locking mechanism has an actuator on which a slider having a transducer mounted thereon for transferring information between the transducer and a storage medium is mounted and which is driven so that the element scans the storage medium, an attracting member which is magnetically attractable with at least a portion of the actuator when the actuator is driven so that the slider is moved to a non-recording region of the storage medium, a support member on which the attracting member is mounted and which is rotatably attached to the base, and a spring which is engaged with the support member and gives elastic force to the support member so that the actuator attracted magnetically to the attracting member is given force in a direction where the slider is directed from the recording region of the storage medium to the non-recording region.

Abstract: A disk drive having an improved method of adjusting the head switch time to improve disk drive performance. In the process of writing or reading long data files, the heads on the actuator are sequentially selected in order to access all the data tracks forming a cylinder in the shortest time. Head offsets are significantly smaller for switching between heads mounted on the same actuator arm than for switching between heads mounted on different actuator arms. Therefore improved disk drive performance is obtained by using two values of head switch time instead of one. The head switch time allocated for switching from a first head on one actuator arm to a second head on a second actuator arm is made longer than the head switch time allocated for switching from a first head on one actuator arm to a second head on the same actuator arm. By allocating longer time for the head switches between different actuator arms, the error flag rate for heads not ready is reduced.

Abstract: An actuator assembly having two coils disposed between the poles of a voice coil motor (VCM) magnet for improved dynamic performance during settling and tracking operations in a disk drive. The two coils in the VCM are connected to separate current sources to allow the current flow in the two coils to have the same sense (clockwise or counterclockwise) or the opposite sense with respect to each other. When the current flows in the two coils have the opposite sense, excitation of the principal in-plane bending mode resonance of the actuator assembly is suppressed allowing the use of an increased servo bandwidth for settling and tracking operations of the disk drive. During seek operations of the disk drive, where maximum torque on the actuator is desirable, the coil currents in the two coils are chosen to have the same sense so that the forces on the actuator from the two coils are additive.

Abstract: A diaphragm isolator frame for supporting a disk drive in a rack or other enclosure while providing isolation from undesirable vibrations from other disk drives or components mounted in the enclosure or from the environment. The diaphragm isolator frame comprises a pair of side rails having isolators formed of thinned portions of the side rails to form diaphragms, each diaphragm having a centrally located press-pin for supporting the disk drive. The thickness and diameter of the diaphragms may be chosen to provide vibration isolation at a desired frequency.

Abstract: A micromechanically fabricated read/write head for charge storage devices comprising a supporting base, a cantilever and a tip with a shaft and frontside end. The supporting base, cantilever and tip form one integral part made of electrically conducting material. The frontside end of the tip is so designed as to allow writing and reading of information in direct contact with the surface of a charge storage device. The shaft of the tip has a small diameter and is surrounded by a strengthening shell.

Abstract: A method is described for operating a data processing system having a plurality of processors to sort a set of data records each having an associated key for governing the sort process. The method comprises determining a range for the key values by sampling the key values. The range is divided into a plurality of quantiles, one for each processor, each quantile having a respective index. At each processor, a plurality of buckets are defined, each bucket corresponding to a respective one of a plurality M.sub.p of subintervals in the quantile, each subinterval having a respective index. The index of the quantile in which the key value lies and the index of the subinterval in which the key value lies are determined directly from the key values using fast operations. Each key is distributed to the processor corresponding to the quantile in which the key value lies.

Abstract: A method of taking a backup copy of a data set, for use with a log, with the data set being open for update by multiple updaters is described. A point on the log is identified (Recovery Time) from which it can be ensured that all data updates identified on the log have been written by an updater from buffers to the data set. This is done by recording a Recovery Time, and then not taking the backup until all the updaters have confirmed that they have written all updates from buffers to the data set. In addition, if tokens are used on the log to avoid having to identify the data set in full, then these are also written to the log before the update is taken.

Abstract: An etched, lubricated swage ball for use in swaging a head gimbal assembly to an actuator arm in a magnetic disk drive, and a method for making the same. The present invention discloses a lubricating system for swage balls used in a disk drive system which is free from transferrable aluminum oxide, other hard materials or excess solid lubricant which could be deposited on the clean disk surface during operation. The swage balls are first pretreated by cleaning and then etching to remove residual alumina from the surface of the swage balls. The cleaned, etched swage balls are then lubricated in a fluorocarbon lubricating system, thereby producing an etched, lubricated swage ball which is cleaner than that found in the prior art.

Abstract: In a disk array system, such as a RAID system, when disks are added thereto, this invention rearranges data without requiring a back-up of the stored data. When new data storage units are added into a RAID system in which each data storage unit is a row and an address range of the data storage unit is a column, a new striping rule dependant on the number of data storage units in the system, inclusive of newly added unit, is determined. Data are rearranged in the storage areas according to the new striping rule. In rearranging one row according to the new striping rule, the data involved in the transfer to one row from the other row, continues to be stored as a place holder block. Data that has been rearranged is accessed according to the new striping rule which data that has not been rearranged is accessed according to the old striping rule.

Abstract: The present invention provides a stacked type actuator arm assembly equipped with a structure for easily fixing lead wires between a coil and a flexible cable. A stacked type actuator arm assembly that is used in a magnetic disk storage is equipped at the coil support portion of a coil support spacer with a small hole through which lead wires and are inserted. Since the spacer is stamped from a flat sheet, a structure for holding the lead wires cannot be freely formed as in a die casting method, but formation of the small hole according to the present invention is easy. During manufacturing, after the lead wires and have been inserted through the small hole, if they are processed in the following fabrication step, there is no possibility that force will be applied to the boundary portion between a coil and the lead wire extending from a wire of the coil which would peel a wire of the coil off.

Abstract: The present invention is an actuator locking mechanism used for an information recording apparatus, having a simple structure and a large securing force. A locking mechanism of the present invention comprises an actuator, an attractable member, a support member, a spring, and an inertia member. While the attractable member and the actuator are attracted to each other, the support member rotates correspondingly to the movement of the actuator due to an impact force applied to an information recording apparatus, the spring provides elasticity for the support member while elastically deforming, moreover the inertia member is rotated by the impact force, and a securing portion of the inertia member contacts the actuator to limit the movement of the actuator due to the impact force.

Abstract: A hard disk drive connector with elastomeric shock mounts reduces the amount of mechanical vibration or shock which can travel to or from the head disk drive. The shock mounts are placed between the system components and the mechanical fasteners of the connector to mechanically isolate the connector. The shock mounts attach to the head disk assembly where they work through compression beams to the card electronics. This configuration isolates the head disk assembly from shock coming from the system through the card electronics. It also isolates vibration emitted from the head disk assembly to the system.

Abstract: A data recording disk file having multiple actuators mounted on a common pivot axis, one of the actuators having fewer arms and lower inertia characteristics than the other. A servo system separately drives each of the actuators for seek repositioning, the lower inertia actuator having a higher performance than the other. A controller selectively records one type of data on the data surfaces associated with the lower inertia actuator, and records all other data on the other data surfaces, thereby providing a disk drive with increased performance appropriate to the data stored on the surfaces associated with the lower inertia actuator. A removable locking pin may be provided which extends through corresponding holes in each of the actuators for maintaining the actuators precisely positioned with respect to each other so that servo information may be written on each of the surfaces in a single process. Additionally, one of the actuators may be provided with a shorter stroke than the other actuators.

Abstract: A multi-track density direct access storage device is disclosed. In accordance with a preferred embodiment of the present invention, a direct access storage device for data storage within a data processing system comprises a housing, a rotatable spindle, at least one disk, and several heads. The disk is fixedly mounted to the rotatable spindle, and the rotatable spindle is rotated by a motor within the housing. A first disk surface of the disk has a first track density and a second disk surface of the disk has a second track density; wherein the second track density is preferably greater than the first track density. Each of the several heads contains a transducer to read and write information from and to the disk during the disk rotation.

Abstract: The present invention provides a crash stop which is capable of adjusting shock absorptivity by employing the same elastic material and where the mounting and demounting operations are easy. A metal pin has a recess in its intermediate portion. An elastic body has three blade portions. In a crash stop, the metal pin is press fitted into the pin inserting hole of the elastic body, and the portion between the support portion and the knob portion of the metal pin is covered with the elastic body. In the boundary between the intermediate portion of the metal pin and the elastic body, a cavity is formed. The support portion is fitted into the crash stop support hole of the base so that it can be freely pulled out and inserted. At this time, the upper end of the blade portion contacts the inner side surface of the crash stop inserting hole of the upper yoke and is contracted, and by the frictional force generated between the crash stop inserting hole and the upper end of the blade portion, the crash stop is locked.

Abstract: A gasket for a disk drive system that seals the connector port for the actuator flex cable to the disk drive housing which is designed to also provide electrical ground contact from the disk drive housing to the actuator flex cable ground lead. In accordance with the new gasket disclosed herein, grounding of the actuator flex cable ground lead to the disk drive housing is accomplished without need of additional fasteners, or additional process steps in assembly of the disk drive.

Abstract: A memory controller performs parity encoding on a plurality of data strings moving between a memory connected via a read path to a data bus connected to a corresponding plurality of storage devices. A write buffer has one input for receiving data for storage in the memory and another input for receiving data from the memory for parity calculation. Two outputs of the write buffer are connected to a parity generator. Circuitry responsive to control signals from the data bus conditions the parity generator to logically and recursively combine the two outputs of the write buffer for supplying an updated parity calculation to the memory via a write path. To provide error detection and correction an ECC generator is interposed between the write path and the parity generator, and an ECC check/correction unit is interposed between the read path and control-signal-responsive circuity. The parity encoding is performed using a code that is associative and commutative.