Xerox Corporation

Other

Martin O Halfhill

James O Jacques

Leonard R Shenfield

Stipe Cizmic

Ronald W Votaw

David L Griffith

Russell K Brunner

Douglas K Mahon

Wayne L Edwards, Jr

A method of transferring data between a data supply and a disk having a track divided into sectors, each sector having an address recording area followed by a data recording area. The method includes detecting a defective area on a data recording area; writing an address of the defective area on the corresponding address recording area; recording data on the data recording area by detecting the defective area with the address and writing part of the data on the data recording area up to the defective area, and writing the remaining data on the data recording area succeeding the defective area; and retrieving the written data by reading the address of the defective area and then reading the recorded data. The apparatus includes a circuit to record a test pattern on the disk, a circuit to sense the recorded test pattern and provide an address of a defective area, a circuit to write the address on the address recording area, a circuit to write data on the disk, and a circuit to read the recorded area.

Method and apparatus for recording data without recording on defective

A servo system including a recording head to sense servo data on a disk track for fine positoning of the head and an external transducer for generating signals representing the coarse position of the head. A micro-processor stores the coarse positon signals which include information as to repeatable error such as wobble of the disk. A compensator maintains information concerning small offsets of the disk due to, for example, temperature variations. During coarse positioning of the head, from one track to a desired track, the stored repeatable error information and stored offset information is used to generate error signals to control movement of a carriage connected to the head, whereby the head follows the repeatable error and offset to arrive coarsely on the desired track. After coarse positioning is complete, fine positioning information from the recording head, which information includes the offset information, and the stored repeatable error information are used to generate error signals to control movement of the carriage for fine positioning purposes.

Utilization of stored run-out information in a track following servo

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 disk drive comprises a housing having a door through which a cartridge including a recording disk therein may be inserted. A spindle drive assembly is mounted in the housing and is responsive to a first set of instructions for rotating the recording disk of a disk cartridge loaded into the housing through the door and onto the spindle drive assembly. An actuator is also mounted in the housing and is capable of controlled reciprocal movements relative to the axis of rotation of the spindle drive assembly. A head carriage assembly is mounted in the housing to the actuator and includes at least one electromagnetic read/write head thereon for reading data from the writing data onto tracks of the recording disk of a cartridge loaded onto the spindle drive assembly. Servo control apparatus is mounted in the housing and is responsive to a second set of instructions for controlling the speed and direction of the reciprocal movements of the actuator. Additionally, read/write apparatus is mounted in the housing and is responsive to a third set of instructions for controlling the reading and writing of data by the electromagnetic head. Further, programmed data processing means is mounted in the housing and is connected to the spindle drive assembly, the servo control system and the read/write apparatus for generating the first, second and third sets of instructions under program control.

Control system for disk drive

In a computer peripheral device having a controllable element and control means coupled to the controllable element and operative in response to a power supply voltage of a predetermined level for controlling the controllable element, an improved power supply means coupled to the control means for supplying said power supply voltage to the control means. The improved power supply means comprises a motor capable of being driven at a predetermined rate of speed, means coupled to the motor and responsive to the motor being driven at the predetermined rate of speed for generating the power supply voltage, and means coupled to the means for generating for supplying the power supply voltage to the control means.

Power supply for computer peripheral device

A disc drive memory device is described utilizing a continuously rotating drive shaft and a roller which rides thereon to effect translational motion of a carriage to move a read/write head between address locations on a magnetic recording surface of a data storage disc.

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San Jose, CA, United States of America

Martin O Halfhill