Conner Peripherals, Inc.

Seagate Technology Incorporated

Mobile Storage Technology, Inc.

Miniscribe Corporation

Seagate Peripherals, Inc.

John P Squires

Louis J Shrinkle

Charles M Sander

Stanton MacDonough Keeler

Donald W Clay

Kurt M Anderson

Thomas A Fiers

Glade N Bagnell

Frederick Mark Stefansky

Bruce D Emo

James Joseph Touchton

Wallis Allen Dague

Steven R Speckmann

John Jay Freeman

Noureddine Kermiche

Alan D Kronisch

A method for assembling and operating a fixed media hard disk drive using a disk or a stack of disks on which servo information is pre-written off the drive spindle. The disks are subsequently mounted on the drive spindle and a set of rotationally concentric &ldquo;virtual tracks&rdquo; for seeking and following in terms of said pre-written servo tracks are defined. The use of the concentric virtual tracks assures minimal actuator motion during drive operation and increases acceptable offtrack tolerances. The off-spindle, pre-writing of the servo information increases the efficiency of the assembly operation and reduces the clean room burden.

Disk level servo write

The software system architecture supports a rotating media in the storage and retrieval of data, where the rotating media stores in data tracks of multiple sectors, through the use of a microcontroller for the execution of a control program that schedules plural control tasks temporally distributed for respective execution during the rotational period of a predetermined track and sector. The scheduling of the plural control tasks is synchronized with respect to data retrieved from the predetermined sector. The plural control tasks include a rotational control task for determining an adjustment to the spin speed of the rotating media, a track following task for determining an adjustment to the alignment of the read/write head with respect to the predetermined track and a sector timing task for determining the position of the read/write head with respect to the predetermined track. The sector timing task also provides for scheduling the rotation control and track following task for execution during discrete intervals during the rotational period of the predetermined sector as well as scheduling the re-execution of the sector timing task with respect to the rotational period of another predetermined sector.

Programmable microcontroller architecture for disk drive system

A hard disk drive system operates from a limited power source to provide for the storage of data on the surface of a rotating hard disk media. An embedded controller incorporates a data channel for transferring data with respect to a hard disk media. The controller includes first and second subsections and a power-down circuit for providing separately switchable power from the power source to the first and section subsections. The controller further includes a processor for controlling the power-down circuit. The processor nominally provides a low duty cycle control signal to the power-down circuit for switching the provision of power to the first subsection of the controller.

Low-power hard disk drive system architecture

A controller in a hard disk drive system for controlling the transfer of data and control signals between a plurality of host processors and the disk drive system. The disk drive system including storage media, at least one transducer for recording data on and retrieving data from the storage media and an actuator for moving the transducers with respect to the storage media. The controller includes a programmed first microprocessor operating under control of a first operating system stored in a first memory unit associated with the first microprocessor for controlling the recording of data on and the retrieval of data from the storage media, the controlling of the actuator to locate the transducer at and to maintain the transducer at a specified location with respect to the storage media. The controller includes a programmed second microprocessor operating under control of a second operating system stored in a second memory unit associated with the second microprocessor for controlling the transfer of data from a requesting host processor to the disk drive system and the transfer of data recovered from the storage media to a requesting host processor and for generating and communicating parameters to the first microprocessor for defining operations to be performed by the first microprocessor. The second microprocessor operates independently of and concurrently with the first microprocessor and the first microprocessor operates independently of and concurrently with the second microprocessor in exercising operations defined by the parameters received from the second microprocessor.

Hard disk drive controller employing a plurality of microprocessors

An apparatus for a disk drive having at least one disk mounted in a housing having a controlled environment defined by the housing. Such a disk drive generally includes, within the controlled environment, one or more transducers for reading information from and writing information to the disk, and at least one actuator for selectively positioning the transducers with respect to the disks. Each actuator includes at least one magnet for providing a magnetic field and an actuator coil, mounted on the actuator, arranged so that a current in said coil creates a force to pivot the actuator. The apparatus comprises a magnet shield encasing each such magnet for preventing matter, generated during the decomposition of said magnet over a period of time, from interfering with the operation of the disk drive.

Magnet shield for disk drive

A multi-layer data integrity system for use in a disk drive controller for ensuring the data integrity as data is transferred through the controller and written and fetched from the disk media. The disk drive controller is partitioned into an interface controller and a low level controller where the interface controller controls the transfer of data to and from the host processor and the low level controller controls the recording and reading from the disk media. The interface controller employs a first error encoding and detecting means for encoding the data as originally received from the host processor. The low level controller employs an error encoding and detecting means for encoding both the received data and the encoding data which was appended to the data received by the interface controller. The low level controller's error encoding and detecting means corrects errors detected in recovered data. The interface controller during a fetch operation receives the data from the low level controller and determines if the data is valid and whether the data received from the low level controller was in fact the data being sought by the interface controller.

Disk drive data path integrity control architecture

A quadrature based embedded servo control system is provided to realize a high track density, high-performance hard disk drive system. Each data sector includes a gray code field spanning the entire width of the data track and a quad-servo burst pattern having first, second, third, and fourth servo burst fields distributed along the length of a portion of the data sector. The center point of the first, second, third, and fourth servo bursts are sequentially offset from the adjacent burst by a radial distance equivalent to one-half of the data track width. The quad-servo burst pattern is used with a track-following algorithm based on the quadrature value of (A+B)-(C+D) to obtain a substantially increased servo lock range. A second gray code field extending substantially the width of the data track and second quad-servo burst pattern substantially identical to the first is provided near a mid-point in the data portion of the data sector to increase the servoing information sample rate and accuracy, thereby permitting substantially increased data track densities to be utilized.

Disk drive system using multiple embedded quadrature servo fields

A multiple actuator disk drive utilizes multiple heads, associated with respective ones of multiple actuators, to read data from and write data to all tracks on the surface of a disk. The positioning of each head by the respective actuator is controlled by embedded servo-information recorded in the data tracks. The data tracks have a density of greater than 2000 tracks per inch. Utilizing two actuators provides access times which are reduced with respect to the access times provided by disk drives having a single actuator and an increased data transfer rate.

Multiple actuator disk drive

A high level controller for maintaining communication with a host processor via a host processor interface for establishing communication paths between the host processor interface, an internal processor and a plurality of storage means. A first means receives indicia from the internal processor where the indicia specifies one of the communication paths and generates control signals for forming the specific communication path requested. A second means receives the control signals from the first means and forms the requested communication path. A third means is connected to the first and second means for controlling the communication of the system with the host processor interface in accordance with control signals generated by the first means. In this manner various data paths for communication between the host interface, internal processor and a plurality of storage means may be adaptably specified and formed to make optimum use of the system.

Flexible host interface controller architecture

A disk drive architecture controls the transfer of data between a host processor interface and a recording media that includes one or more disk surfaces for storing data. A low-level data controller controls the transfer of data between the disk surfaces and a data buffer. An interface controller controls the transfer of data between the host interface and the data buffer. An arbiter and buffer controller, responsive to data transfer requests from the low-level and interface controllers, arbitrates data storage and retrieval accesses of the data buffer. The low-level and interface controllers operate substantially independent of one another in performing their respective control operations. Consequently, data is transferred bi-directionally through the data buffer at the optimum timing for both controllers.

Multiple microcontroller hard disk drive control architecture

A multiple actuator disk drive utilizes multiple heads, associated with respective ones of multiple actuators, to read data from and write data to all tracks on the surface of a disk. The positioning of each head by the respective actuators is controlled by embedded servo-information recorded in the data tracks. The data tracks have a density of greater than 2000 tracks per inch. Utilizing two actuators provides access times which are reduced with respect to the access times provided by disk drives having a single actuator and an increased data transfer rate.

The read/write channel is programmatically adaptable to the media used for storing data in response to data signals and the read/write head used to transfer the data signals to and from the media. Adaptability is provided by progammable signal processing elements in the read/write channel. The programmable elements include a read threshold element for determining whether data signals transferred from the media exceed a data discrimination level determined by a first programmable value, and a data window element for determining whether data signals transferred from the media occur within a data signal window whose timing, relative to a data clock signal, is determined by the second programmable value. Additional programmable elements include an amplifier element that is programmed to provide a corresponding level of write current and a precompensation block for providing data signal precompensation. The programmable values are deterined by the disk drive uniquely for the media, read/write head and the read/write data channel.

Disk drive system employing adaptive read/write channel controls and

The disk drive system includes an actuator, responsive to an adjustment value, for adjusting the position of a data head with respect to data tracks located on the surface of a disk, and a controller coupled to the data head and to the actuator. The controller receives servo information read from the surface of the disk by the data head. In turn, the controller determines an adjustment value to be applied to the actuator. The adjustment value is calculated dependent on a predetermined variable gain factor. Where the controller determines the position of the heat is oscillating about the center line of a predetermined data track at a frequenc above a predetermined frequency, the controller reduces the gain factor applied in determining the adjustment value.

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Boulder, CO, United States of America

John P Squires