Xerox Corporation

Sharp Corporation

Douglas K Mahon

James O Jacques

Stipe Cizmic

Leonard R Shenfield

Martin O Halfhill

Ronald W Votaw

Wayne L Edwards, Jr

Apparatus and method for evaluating a recording system which simultaneously passes the reproduced data through a plurality of sampling windows leaving different effective window size and compares the sampled data with the original data to provide an evaluation of error.

Method and apparatus for evaluating recording systems

An exerciser is provided for use with a disk drive of the type having a microprocessor, a first memory for storing microcoded control programs for the drive, a second memory for storing instructions for the head carriage servo control apparatus, an address bus for supplying address signals from the microprocessor to the first and second memories, and a data bus for supplying program instructions from the first memory to the microprocessor, and for supplying instructions from the second memory to the servo control apparatus. The exerciser developes track address signals that are supplied onto the data bus for application to the microprocessor. A third memory is included in the exerciser for storing diagnostic programs. A decoder is also included for decoding an address signal on the address bus in order to generate a new address signal for the third memory. Program instructions accessed from the third memory are supplied onto the data bus for application to the microprocessor.

Self-diagnostic method and apparatus for disk drive

A method and apparatus for restoring the electromagnetic read/write head of a disk drive from a position between a data-field track located closest to the axis of rotation of a disk loaded in the drive and a data-field track located furthest to such axis of rotation, to a position over the latter data-field track. A first predetermined code is prerecorded on each data-field track and a second predetermined code is prerecorded on each of a plurality of guard-band tracks. The head is first moved in a direction away from the axis of rotation of the disk at a predetermined velocity. The code stored on each track is read and detected as the head is moved thereover. The head is stopped over a track when the code read and detected therefrom is the second predetermined code. Then, the head is moved in a direction toward the axis of rotation of the disk and stopped over the data-field track located furthest from the axis of rotation of the disk.

Restore method and apparatus for disk drive

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Boulder Creek, CA, United States of America

Douglas K Mahon