Abstract: A physical drive divided into at least two logical volumes, each volume containing a plurality of data storage segments, at least some of the data storage segments in one volume being physically interleaved with at least some of the data storage segments in the other volume. The purpose of this configuration is to increase the average rate of data transfer between a computer and multiple logical volumes residing on a single physical drive.

Abstract: A novel self-securing sealing gasket for a disk drive assembly housing ensures predictable securement of the sealing gasket to a mounting surface. Elastomeric material is preferably molded to a rigid frame. The elastomeric material defines the sealing member of the gasket, while the frame provides structural rigidity and concomitant ease of handling during assembly and disassembly of the disk drive assembly housing. A plurality of recesses are provided along the periphery of the frame for mechanically coupling with the sealing member. The compliant sealing member includes a first sealing surface having a convex profile. A plurality of vacuum cavities are integrally incorporated along a second sealing surface of the sealing member for providing vacuum coupling between the second sealing surface and the mounting surface of the base of a disk drive assembly housing.

Abstract: A method for increasing data storage on a hard disk drive is disclosed herein, the method including determining a capacity goal for the disk drive, partitioning the usable disk surface on the disk drive into regions, and calculating a transfer rate based on the capacity goal and the usable disk space. The rate at which data may be transferred is then increased by a first selected quantity and/or decreased by a second selected quantity to establish a higher and/or lower transfer rate. For multiple data heads used in an individual disk drive unit, a first group of heads is partitioned from the remaining heads based on a particular selection criteria, and the remaining heads are arranged into a second group. The first group of data heads then operates at a higher transfer rate than the second group of data heads, and an algorithm for reading and writing data at the different rates is created.

Abstract: A method and apparatus for optimizing positional data for use in connection with a hard disk type magnetic memory storage device. The apparatus includes a pattern encoded on a dedicated track of the hard disk including first and second set of signals repetitively encoded in a series of cells. The method includes the steps of periodically accessing the dedicated track with the read/write head and calculating amplitude and phase information for a trigonometric instantaneous correction function. Amplitude and phase information are subsequently stored and the positional signal for the read/write head is continually modified by a most recent determination of the correction function. The apparatus of the present invention includes circuitry for distinguishing between sub-elements of the repetitive pattern on the hard disk.

Abstract: A plurality of movies are distributively stored in digitally encoded form on a mass storage unit such as a Redundant Array of Inexpensive Drives (RAID) disk drive array such that they can be viewed on demand by multiple users. A video server receives movie requests from users, and retrieves and transmits the requested movie data from the RAID array to processors at the respective user locations. The processors decode the retrieved data to produce video picture and audio information and display the corresponding movies on monitors. Temporal instantaneous digital data rate signatures for the movies are computed and stored, and a current composite signature is computed by summing the signatures for all movies currently being shown. When an additional movie is requested, the signature for the additional movie is combined with the current composite signature to produce a new composite signature.

Abstract: A disk drive system with adaptive positioning employs one or more storage disks for recording data, one or more read and write heads for performing input/output operation on the disks, with at least one of the heads being used as a servo head, a head-positioning mechanism for controlling the movement of the heads, and a digital compensator for predicting the post-seek displacement of the heads due to internal accelerations and to provide a compensating control signal to the head-positioning mechanism. The compensator includes means for approximating an nth order transfer function and learning algorithms for adapting to the dynamic response characteristics of an individual disk drive unit. The positioning of the heads is adapted to minimize post-seek displacements through trial seeks executed at disk startup and continually through background processes performed during normal input/output operations.

Abstract: A versatile head positioner stop is provided which bi-directionally limits movement of a head positioning device in a Winchester hard disk drive system. The head positioner stop cushions the impact of the head positioner when it reaches predetermined limits. The head positioner stop has a base and means for mounting the base to the fixed disk drive housing in addition to a pair of side members affixed to the base and provides three distinct stages of resistance for accurately positioning the heads and minimizing the risk of head or disk damage during normal operation and power failure conditions. The head positioner stop is pre-stressed to improve dynamic energy absorption during head positioner crashes.

Abstract: A fail-safe, magnetically coupled head positioner latch assembly for a Winchester-type disk drive comprises a rotatably mounted latch member including an outwardly extending latch arm and tang, and a solenoid assembly. The latch arm is adapted for engaging the head positioner in a parked position, and rotating to a non-interactive position with the latch arm being non-interactive with the head positioner. Magnetic coupling force between a permanent magnet structure and the solenoid assembly causes the latch arm to remain in the non-interactive position during normal disk drive operation. Activation of the latch is accomplished by applying current to the solenoid which generates a magnetic field opposite to that of the permanent magnet structure causing the rotatably mounted latch assembly to rotate so that the latch arm engages the head positioner.

Abstract: A precision magnetic head positioner assembly for a Winchester-type hard disk drive storage system includes a main rotatable integral head positioner body and an integral magnetic coil assembly. The positioner body includes outwardly extending integral head positioning arms and a seating surface comprised of two angled lateral seating surfaces. The integral magnetic coil assembly comprises a coil frame and a mounting surface having two angled lateral mounting faces which engage the positioner angled seating surfaces for mounting with fasteners. Precision self-alignment of the positioner seating and bobbin mounting surfaces is provided by an alignment ledge protruding outwardly from the positioner seating surface which engages the lower edge of the bobbin mounting surface. An interference between the positioner seating surface and bobbin mounting surface angles improves mounting alignment and stability.

Abstract: The head positioner for a Winchester type hard disk drive digital storage system includes a main rotating metal body portion made of magnesium or other lightweight metal and having outwardly extending, integral, head positioning arms. The shape of the arms is such that the rotary moment of inertia is minimized while maintaining high resistance to vertical and in-plane bending, torsional twisting and shock, which cause the head to move off track. The integral arms are tapered in a curved fashion having an inner base portion and an outer narrower end to which a load beam and a magnetic head are secured. Three openings are provided in each of the integral arms, including a generally arch shaped opening adjacent the base of each arm and two outer generally oval openings tapering down in their transverse dimensions generally corresponding to the tapering of the arms.

Abstract: A system for slimming pulses which represent the data stored in a hard disk drive assembly. The pulse slimming system comprises a delay line with the pulse applied in one polarity to a central tap. The same pulse is applied in the opposite polarity to taps along the delay line on either side of the central tap. The pulses applied to either side of the central tap are controllably attenuated by amplifiers controlled by a microprocessor. The signal which is present at the output of the delay line is the sum of the original pulse with the attenuated pulses applied to either side of the central tap of the delay line subtracted from the leading and trailing edges of the pulse applied to the central tap.

Abstract: A hard disk drive digital storage system provides increased power efficiency and reduced power losses by using a switching regulator type DC to DC power converter, to control spindle motor speed, in which a variable duty cycle, low "ON" resistance n-channel power MOSFET transistor is located near the ground side of the motor drive circuit. A voltage booster circuit provides higher gate control switching voltages to the motor power phase commutation switching transistors. A sense resistor is connected between the converter and ground, and the voltage developed across this sense resistor provides a signal which is coupled to the motor control circuit to vary the duty cycle of the converter to regulate the peak current applied to the motor.

Abstract: Initial start-up of a polyphase, brushless DC motor (used for a hard disk drive system) is accomplished by sequentially applying current to each of the phases of the motor. When a back EMF zero-crossing is detected in one of the phases of the motor, after an appropriate delay to allow the next phase to come into position, current is applied to that phase. Thus, the position of the rotor is determined from the back EMF zero-crossing of the phase to which power is currently being supplied. A delay proportional to the speed of the motor is used between the detection of a back EMF zero-crossing and the powering of the next phase in sequence.

Abstract: An efficient redundant array of mass storage devices includes a plurality of hard disk drives, a controller or processor associated with each hard disk drive for calculating partial parity data and parity data, a host computer and at least one bus for communications between the host computer and the plurality of hard disk drives. The controller of a drive calculates the partial parity, which is the Exclusive Or function of the old data and the new data which is to be stored into the drive. New data is written to the location in the disk drive from which the old data was obtained. The partial parity data is transferred to the controller of another drive which contains the old parity data for the location to which the new data was written, and that controller calculates the new parity which is the Exclusive Or of the partial parity and the old parity. The new parity is written to the location on that disk drive which formerly held the old parity.

Abstract: An actuator lock to hold the disk drive positioner in the parked position after shut down includes a latch arm extending from a selected portion of the positioner, a solenoid, a locking lever and a latch. The solenoid has a coil and an armature. The armature is moveable between a normally biased first armature position and a second armature position. The solenoid coil when energized by a current pulse upon shut down of the disk drive moves the armature into the second position. The locking lever is rotatably mounted to the armature and has a first end. The locking lever is movable between a normally biased first lever position and second lever position. The first end engages the latch arm when the positioner has been brought to the parked position by the current pulse and the armature coil has also been energized. When the armature is in the first armature position, the locking lever is non-interactive with the latch arm.

Abstract: A hard disk drive digital storage system provides increased efficiency and reduced losses by using a switching regulator type power supply in which a variable duty cycle, low resistance n-channel field effect transistor is located near the ground side of the motor drive circuit. A voltage booster circuit provides higher switching voltages to the motor power phase control switching transistors.

Abstract: Magnetic data read/write apparatus is disclosed for use in connection with a magnetic data storage disk. The apparatus includes a read/write head mounted onto a positioning device along with several electrical leads that extend from the read/write head to an interconnect pad mounted on the positioning device. The interconnect pad includes an electrically-conducting layer divided into several separate conducting paths corresponding to the number of leads to the read/write head. A portion of each separate conducting path is exposed to facilitate electically-conducting connections to the read/write leads. Additional portions of each separate conducting path is exposed to facilitate electrically-conducting connections to other electrical connectors so as to obviate further manipulation of the leads to the read/write head. The apparatus further includes a flex cable structure having a conducting layer divided into several separate conducting paths corresponding to the conducting paths in the interconnect pad.

Abstract: A sector pulse generator circuit for a hard disk drive assembly includes an angular position counter, a sector counter, a sector limit register, and a pulse generator. The circuit generates a sector pulse when the count in the angular position counter equals the count in the sector counter. When the count in the angular position counter exceeds the count in the sector counter, the sector counter is incremented by the number of clock pulses in a sector of the current track. The sector limit register stores the number of complete sectors in the current track.

Abstract: An improved switching regulator .Iadd.DC-DC power converter or .Iaddend.power supply with a variable duty cycle is disclosed which forms part of a compact Winchester disk drive system having a storage capacity in excess of 380M bytes of information. The switching regulator is designed for frequencies in excess of 80 kilocycles per second and may therefore be construced using smaller capacitive and inductive elements. Also, very low heat dissipation and high regulator efficiency may be achieved by the improved .Iadd.power converter or .Iaddend.power supply to drive a brushless D.C. motor encased within a hard disk assembly where no separate fan or cooling system is used to aid in heat removal. Circuitry is provided to control the motor speed while simultaneously limiting the motor current to a predetermined level. This is a achieved by controlling the voltage applied to the motor by suitably adjusting the duty cycle of the switching regulator.