International Business Machines Corporation

Thomas W Glaser

Christopher H Bajorek

Richard Greenberg

Gordon James Smith

Klaas Berend Klaassen

David A Thompson

Charles R Nielsen

George R Santana

John R Reidenbach

Michael L Workman

Robert E Schopp

Timothy Joseph Chainer

Hal Hjalmar Ottesen

Earl Albert Cunningham

Mark David Hagen

John Stewart Best

John Jeffrey Stephenson

Kevin Jack Erickson

Dana H Brown

Robert A Scranton

Jerry Lee Neubauer

Todd Barry Anderson

Richard H Estry

Hjalmar H Ottesen

Nigel F Misso

John J Neesz

Dean C Palmer

Jerr L Neubauer

Avijit Mukherjee

An apparatus and method for correcting for track misregistration when a slider or head assembly contains a separate read element and write element. The offset is determined at a first position and at a second position of the actuator arm assembly. From these offsets a constant and a multiplier are determined for determining an offset as a function of the cylinder location. Also disclosed is a method and apparatus for minimizing distance traveled to prevent misregistration when repositioning between the read element and a write element. The read element is intentionally offset from the write element at an angle so as to minimize the distance traveled across the disk.

Method and apparatus for positioning transducers to correct for read and

A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Adaptive system for optimizing disk drive power consumption

High density magnetic disk storage and semiconductor module technologies are combined to provide a disk drive using a standard multilayer ceramic substrate as the disk drive base support member to support spindle and actuator assemblies including 1 inch diameter disks. The ceramic substrate has components and very large scale integration (VLSI) chips mounted directly thereon to avoid use of one level of packaging and presents standard pins to mount the drive using standard sockets to afford economy and reliability.

Magnetic disk storage device with the base provided by an electronic

A data processing system is disclosed having a direct access storage device (DASD) subsystem comprising a number of separate physical housings, each housing having a number of disk supporting spindles mounted therein. The velocity of rotation of the spindles within a housing is synchronized, and the rotational position of the spindles may be locked into a fixed relationship. When number N of disk supporting spindles are provided, spindle rotation is synchronized, and mirrored data files are written out of phase by 360/N degrees, thereby providing reduced latency time during a subsequent read operation, while at the same time providing data integrity through the use of redundant data files.

Method and apparatus for programmably controlling spindle

A high speed, small diameter disk storage system having a plurality of disk drive devices utilizing disks with a nominal 65 mm diameter rotated at a speed of approximately 10,000 RPM which can be optimally arranged in a four drive system to match the space geometry of the traditional half-high flexible disk drive used in a personal computer.

High speed, small diameter disk storage system

A structure and organization for a magnetic disk drive provides for optimizing the volumetric storage density within a device form factor by optimizing the number of disks. The spindle and dual rotary actuators are respectively supported at each side by a pair of support plates that are separated and supported by not only the spindle and actuator shafts, but also the voice coil motor core pieces and tie plates which carry shock mounts. This head-disk assembly is shock mounted in the lower part of a two part enclosure wherein the enclosure parts are aligned and separated by elastomer guides and the separation covered by a compliant tape to complete the enclosure. Both actuators use a common servo surface while one actuator carries upwardly facing transducers and the other downwardly facing transducers so that each arm extending between disks mounts, but a single suspension-transducer assembly to reduce interdisk spacing. The enclosure occupies the entire vertical height of the form factor and the head-disk assembly occupies the full available height of the enclosure interior to accommodate as many disks as possible. Electrical components are excluded from the axial sides of the stack of disks.

Rigid magnetic disk drive head disk assembly and enclosure structure

A sector servo seek control samples each sector to obtain sector time, the track identification within a sequence of track types and a position error signal for a track location to track location seek. The device during each sector determines the actual transducer track location and the next sector projected track location with respect to the sequence of track types. The projected track location is corrected using the error signal to find the actual location, but if a sector signal is missing or erroneous, the projected location is used as the actual location, permitting a composite correction to be made when a correct sector signal is obtained. The seek time is minimized by using maximum acceleration followed by maximum deceleration while not exceeding a velocity value that would cause the device to overshoot the target track using full deceleration.

Sector servo seek control

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Rochester, MN, United States of America

Thomas W Glaser