Quantum Corporation

Texas Instruments Corporation

Alps Electric Co., Ltd.

Michael G Machado

Ronald R Moon

Bruce R Peterson

Clifford M Gold

Daniel E Barnard

Gregg J Uhlendorf

Hoa V Luong

Patrick M Weiher

James H Do

Mark E Strysko

Curtis H Bruner

Thomas G Cooper

Tuong T Quan

Steven G Campbell

William Robert Krenik

William G Moon

Hung C Nguyen

Thomas A Tacklind

James E Chloupek

Avraham Perahia

Richard K Oswald

A method of driving a motor without initial back rotation includes the steps of identifying a rest position 22 of a storage medium 20, mapping the rest position of storage medium 20 to a motor drive sequence, and driving the motor with the motor drive sequence, thereby enabling motor start-up without back rotation. The method is applicable to unipolar and bipolar drive methods as well as inductive read type and magneto-resistive type heads.

Start-up commutation method for a rotating magnetic storage device

A programmable data sequencer transfers fixed length data blocks between variable length storage segments of a magnetic storage disk and a buffer memory within a data storage device. The data sequencer includes a stack memory for holding user byte count values read from a header field preceding each data sector having variable length split storage segments. Each byte count value indicates respective length of a following variable length storage segment, so that the storage capacity of each segment is dynamically determined by the data sequencer in real time by popping the user byte count value from the stack into a storage segment length counter and by counting down the count value within the segment length counter.

Miniature disk drive having embedded sector servo with split data fields

A disk file subsystem is disclosed which utilizes a track address decoding circuit which converts the track address which is recorded on the magnetic media in Gray code according to a 1/6 (2,8) run-length-limited recording code to its corresponding binary track address.

Track address detecting means by HDD sector servo method

A miniature disk drive achieves storage densities of at least approximately 1700 tracks per inch per storage surface of a storage disk defining a series of radially extensive servo sectors embedded within circumferential zones of data tracks. The sectors are recorded at a constant data transfer rate while each zone has a data transfer rate adapted to disk radius. The drive includes a head and head positioner, a read preamplifier for amplifying analog signals read from, and for amplifying signals to be written to, a storage surface. A circuit board carries drive electronics including a read channel, a servo processing circuit for recovering head location information from the servo sectors, a data block sequencer for sequencing data blocks between a buffer and the storage surface, a buffer memory controller for controlling the buffer, a bus level interface circuit for transferring data blocks between the buffer and a host computer, and a programmed digital controller which functions within a head position servo loop and which also controls the sequencer, buffer controller and bus level interface circuit. As one feature, the servo sectors split data blocks into segments. Segment byte counts in each data block header are used by the sequencer automatically to assemble the segments into data blocks during read and to divide the blocks into segments during write. A single VLSI circuit including the sequencer, servo processing circuit, memory controller and an interface to the microcontroller is disclosed.

High capacity submicro-winchester fixed disk drive

An on-the-fly error correction method and apparatus for correcting a data block within a stream of substantially contiguous data blocks during a data decoding process, each block having a Reed-Solomon error syndrome calculated and appended during an encoding process. The method comprises the steps of: passing the block through a syndrome remainder recovery circuit to obtain a remainder related to the error syndrome, comparing the remainder with zero to determine if an error burst is present, and if an error burst is present: latching the remainder into a remainder latch in order to free the syndrome information recovery circuit for the next data block of the stream, causing a multitasked microcontroller to call and execute an error correction service routine and thereupon selectively transferring the remainder from the remainder latch to the microcontroller, determining with the microcontroller the location and a corrected value for the error burst in accordance with a Reed Solomon error correction algorithm, and substituting the corrected value for the error burst within the block detected to contain the error burst before it is delivered to a host system. Cross checking the correction, and error detection of data block ID fields is also disclosed.

On-the-fly error correction with embedded digital controller

A disk data storage subsystem includes a head and disk assembly. A plurality of sectors in data tracks include a servo portion containing a prerecorded pattern of a plurality of repeating, time staggered, non-phase-coherent bursts, each burst having a predetermined integral fraction radial offset relative to the other bursts. The head is positionable relative to the tracks by a voice coil in response to information derived from a servo portion, a programmed microcontroller supervisor receives operational data storage and retrieval commands from a host system with which the subsystem is operationally associated and controls the position of the head during track seeking and following operations in response to servo information read by the head from each servo portion and further in response to the commands, an interface, with an SCSI interface controller, under the control of the microcontroller supervisor receives the commands and data blocks from the host system and for sending commands, status words and data blocks to the host system, a data sequencer and memory controller under the control of the microcontroller manages flow of data blocks to and from the disk via the head.

High capacity disk file with embedded sector servo and SCSI interface

A rotating disk data storage subsystem is disclosed for recording and retrieving data in blocks of predetermined finite length, each block of data including an error correction code syndrome portion calculated in accordance with a predetermined Galois field error correction algorithm. The subsystem includes a data controller including a unitary, cyclic error correction code syndrome generator/decoder for processing each incoming byte of the block in accordance with the said error correction algorithm in a manner which tests for the presence of any errors and which generates error values from which the errors may be located and corrected. A microprocessor controller has access to the data controller for testing to determine if the generator has determined the presence of an error for an incoming block, and if so, for obtaining the error values. The microprocessor is programmed to process the error values to determine the location and nature of at least one error, and having access to the buffer memory whereby a data byte of the block including an error may be removed and a corrected byte substituted in its place.

Disk drive with improved error correction code

An encoder-decoder apparatus is disclosed for encoding and decoding code words of a predetermined code scheme in which which ONE bits thereof are separated by at least d ZERO bits and not more than k ZERO bits, in a serial bit stream path from and to components of serial data words each being of n parallel data bits in a data word transmission path, wherein the number of bits of each code word bears a three to two relation with respect to the number of bits of each component of the data word, and where n equals an even integer. The encoder-decoder includes an encode/decode clocked shift register connected to the serial bit stream path for receiving and framing each incoming code word and for putting out each framed incoming code word in parallel bit format, and for receiving each outgoing code word in parallel bit format and for putting out each outgoing code word into the serial bit stream path; an encode/decode serializing and deserializing shift register latch connected to the data word transmission path for receiving and latching each data word coming in from, and for receiving and latching each present data word going out to, the data word transmission path; an encoder for encoding, and a decoder for decoding. The serializing and deserializing shift register latch is clocked at a first rate corresponding to the latching of each incoming and outgoing data word of n bit length and a second rate by which the shift register latch is shifted by the number of bits of the data word component.

Integrated encoder decoder for variable length, zero run length limited

A high performance, low cost rotating disk data storage subsystem includes a head and disk assembly. A plurality of sectors in data tracks include a servo portion containing a prerecorded pattern of a plurality of repeating, time staggered, non-phase-coherent bursts, each burst having a predetermined integral fraction radial offset relative to the other bursts and having a constant frequency preamble field followed by a unique value field related to its burst spatial location. A head is positionable relative to the tracks in response to information derived from a servo portion, a programmed microcontroller supervisor for receives operational data storage and retrieval commands from a host system with which the subsystem is operationally associated and controls the position of the head during track seeking and following operations in response to servo information read by the head from each servo portion and further in response to the commands, an interface under the control of the microcontroller supervisor receives the commands and data blocks from the host system and for sending commands, status words and data blocks to the host system, a data sequencer and memory controller under the control of the microcontroller manages flow of data blocks to and from the disk via the head and stores the information read by the head means from said unique value fields for subsequent processing by the microcontroller. A servo burst pattern providing phase quadrature and absolute position information, a servo writer, a servo qualification area and a timer, a media defect management method, an amplitude measurement circuit, and a time division control program for the microcontroller are aspects of this invention.

Growing community of inventors

Boulder, CO, United States of America

Michael G Machado