International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Peter Kui Ho

Louis Joseph Serrano

Mantle Man-Hon Yu

Jeffrey Joseph Dobbek

Daniel James Malone, Sr

Scott Arthur Thomas

Kishan Kumar Kumbla

Blake O Finstad

Paul M Cisewski

A method and apparatus for providing a marker at the end of the adaptive self-servowrite process for adaptive formatting via the self-servowrite process. The mark is used later in the drive manufacturing process to identify the number of tracks written on the surface and thus determine the appropriate format to use in the drive.

Method and apparatus for providing a marker for adaptive formatting via a self-servowrite process

Provided are a method, system, and program for estimating coil resistance of a voice coil motor for an actuator assembly in a disk drive system. An estimation is made of a calibration coil resistance during a calibration operation. A determination is made of a distance moved during a seek operation. The determined distance and the calibration coil resistance are used to estimate a current coil resistance following the seek operation.

Method, system, and program for estimating coil resistance of a voice coil motor in a disk drive system

A direct access storage device (DASD) servo control system includes a servo controller that makes an estimate of disk actuator arm position and velocity as for a regular, expected PES signal sample time, and then alters the estimate for an odd sample time using a simplified estimation function. The altered estimate is generated after determining the amount of time by which the odd sample time is longer than the regular sample time. An odd sample time event is recognized and the odd sample time is forced longer than the regular sample time by skipping a disk control signal computation interval. In this way, the estimated position and velocity of the disk arm is improved for odd sample times, even where the change in one PES sample time may be unrelated to the change in any subsequent PES sample times.

State estimator alteration for odd sample times in a disk drive servo control system

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Morgan Hill, CA, United States of America

Peter Kui Ho