Abstract: A transfer protocol in a transfer system adapted for transferring compressed audio signals in a compressed form for recording on a recording medium is disclosed. The management data for managing compressed audio signals recorded on the recording medium are generated responsive to the information sent from the server in order to generate the management data without exchanging the management data between the server and the client. A transfer system in which, if data are previously recorded on the recording medium loaded on the client side, the management data can be edited for additionally recording data on the recording medium without modifying the compressed audio data and management data already recorded on the recording medium, is also disclosed.

Abstract: A method and apparatus for positioning a head over a track in an information recording medium to eliminate head positioning error. Data tracks are concentrically formed on a magnetic disk, and identification information for identifying each data track is recorded so as to correspond to each data track. The identification information consists of first and second gray codes, and the first gray code is of n-1 bits where n represents the number of bits of a track address and set for each block so that it has a value different among a plurality of blocks each consisting of a plurality of data tracks. The second gray code is of three bits, and set for each data track so that it represents a value which differs between data tracks contiguous in the radial direction of the disk and circulates for every three or more blocks continuous in the radial direction of the disk. Head positioning is determined based on reading the first and second gray codes by the head.

Abstract: A method of and a system for efficiently using split information stored in an unnecessary data sector, thereby reducing unnecessary data.

Abstract: A data storage system that is capable of performing a double check on data read from a storage media to determine whether the data is the data desired by a requesting host computer. If the data is not the desired data, the system discards the data before it reaches the host. The data storage system uses a randomizer unit having a variable initialization value. The initialization value is based upon the address of the data storage location being accessed by the host. If the initialization value used to read a piece of data is different than the value used to write the data, uncorrectable data errors result and the data is discarded.

Abstract: A method and apparatus for writing binary servo data into the servo bursts contained on the storage medium of a storage device. The binary servo information may include track identifying information such as a track number, cylinder number, head number, sector number, index and/or SID. A burst includes T time slots, each slot comprising one cycle of the servo burst frequency, and the servo data to be written comprises X bits of binary data. Each one-bit of the servo data is represented as a slot containing a transition, and each zero-bit is represented as an empty or null slot. In this manner, the present invention provides a highly bit-efficient scheme for representing digital servo data. A high quality PES signal is assured by writing the binary servo information in such a manner as to guarantee a threshold number of transitions per burst as required for accurate peak-hold detection.

Abstract: The present invention relates to an information recording medium for a disk drive having improved recording efficiency. The information recording medium is provided with discrete servo and data areas, with servo information being recorded in the servo areas. Cylinder information included in one or more servo areas is used to locate particular data areas on a disk. In the present invention at least partial cylinder information in one servo area is used to locate more than one data area by dividing the cylinder information into different servo areas, or using the cylinder information in one servo area to locate a data area associated with another servo area. By recording the divided cylinder information in respective ones of the servo areas provided on a given cylinder on the disk, less disk space is needed for cylinder information, so the size of the data areas can be increased and recording efficiency can be improved.

Abstract: In a disk drive which has a magneto-resistance (MR) element as a read element and where servo areas and data areas are separated and recorded on a disk, the disk drive is so constructed as to prevent a read error resulting from the roughness of the disk, i.e, a read error of a thermal asperity. There is provided a structure where, in a servo area, a read error of a start bit of a Gray code is prevented by a thermal asperity which occurs immediately before the Gray code, and where an erase area is detected.

Abstract: A buried servo signal on tape is modulated to provide information. According to the modulation, each of a plurality of sets of cycles has at least a selected cycle modulated to represent at least two modulation values. The modulation of the selected cycles of a group of sets of cycles provides a string of modulation values. The modulation values formed identifiers of longitudinal physical location on tape or other tape identifying information (e.g., number of frames per track and cartridge type code).

Abstract: A servo mark detection device includes a synchronizing circuit, first and second shift registers, a frame pattern detection circuit, a control circuit, and a servo mark comparator. The synchronizing circuit detects a peak of the signal amplitude of a data pattern and outputs a synchronization data signal synchronized with a clock. The first shift register sequentially stores the synchronization data signal and outputs a latch data signal. The detection circuit determines the frame pattern of the latch data signal, outputs a determination data signal, determines a phase shift of the latch data signal with respect to the clock, and outputs a phase correction signal. The control circuit outputs a frame pulse signal at a predetermined clock period, outputs a frame pulse signal at a timing corrected with respect to the predetermined clock period on the basis of the phase correction signal, and outputs a check window signal when a predetermined number of frame pulse signals are output.

Abstract: The present invention pertains to a method for determining if data read from a storage medium has been read from physical block address (PBA) other than the expected PBA. Data that is stored on the data storage medium is encoded in accordance with a protocol that includes randomizing the data and combining the first k.times.2t bytes of the data with a PBA string, where t is the error correction capacity associated with the error correction technique used in the data storage system and k is the number of bytes of the PBA that are used in the PBA string. In addition, the data is k-way interleaved with parity data appended to it. When the data is read from the data storage medium, the data is decoded using a scheme corresponding to the encoding protocol. If errors are present in the data and exceed the error correction capacity, the first 2t bytes of each interleave are marked as erasures and a second correction is performed by an error correction unit.

Abstract: A disk recording medium includes a servo track pattern where a gray code field has been deleted, capable of embodying a high capacity hard disk drive. The hard disk drive which uses as a recording medium, a disk having a plurality of servo sectors for each track, includes: a first plurality of servo track patterns on each track, the number of first servo track patterns equal to the total number of first servo sectors existing on each track divided by the number of heads of the hard disk drive, each of the plurality of servo track patterns having a gray code field for providing information for each track; and a second plurality of servo track patterns on each track, the number of second servo track patterns equal to the total number of servo sectors existing on each track minus the number of first servo track patterns, each of the second plurality of servo track patterns corresponding to the first servo track pattern but with the gray code field deleted.

Abstract: A servo decoder is disclosed for disc storage systems that operates according to a novel coding scheme capable of accurately decoding detected codewords representing servo track address during seek operations, even when the recording head flies between two adjacent tracks, and capable of correcting errors in the detected codedwords caused by noise in the read signal, such as inter-symbol interference. In a first embodiment, the coding scheme comprises an error correcting code (ECC) capable of correcting a predetermined number of bit errors in the detected codewords. To achieve the equivalent effect of a conventional Gray code, the codewords are arranged such that adjacent track addresses differ by a number of bits equal to the minimum distance of the ECC code. In a second embodiment, the servo code corrects certain minimum distance error events associated with a trellis type sequence detector.

Abstract: A method of judging a sector synchronous signal for a disk reproducing apparatus, includes a first step for decoding and storing a synchronous signal, a second step for comparing the decoded synchronous signal with a reference sector synchronous signal, a third step for assuming the detected synchronous signal to be a sector synchronous signal when the decoded synchronous signal and the reference sector synchronous signal are identical based on a result of the second step, a fourth step for judging whether the synchronous signal stored before the decoded synchronous signal indicates a desired state, and a fifth step for finally judging that the assumed sector synchronous signal is a sector synchronous signal based on a result of the fourth step.

Abstract: Data is recorded over tracks formed on a tape storage medium at a predetermined track pitch selected from a plurality of track pitches. The selected predetermined track pitch is larger than the minimum track pitch among the plurality of track pitches. First absolute addresses of tracks formed by the minimum track pitch are decided. Second absolute addresses of tracks formed by the predetermined track pitch are decided using the first absolute addresses. The data and the second absolute addresses are recorded over the tracks formed by the predetermined track pitch. In decision of the second absolute values, a value of (n-m) high order bits of n bits of each of the second absolute addresses is increased per track formed by the predetermined track pitch, where n is a natural number of two or more and m is another natural number of one or more but smaller than n. The first absolute addresses are also expressed by the n and m bits.

Abstract: A method and apparatus is disclosed for fast access to any logical block on a media not containing logical block addressing. Categorizing marks such as filemarks or setmarks are provided on the tape medium at various points along the medium. The medium is divided up into a plurality of physical blocks. To permit fast access to a logical block on the tape, a connection table in the form of a block map is provided which establishes a relationship between logical blocks and the tapemarks, and defines physical positions of at least some of the tapemarks.

Abstract: An index determining unit determines that a current position in a disk medium corresponds to a true index when reaching a true index pattern of servo information recorded in the disk medium. The determination is used for reading predetermined servo information so as to perform a servo control operation of a disk reading/writing head. The disk medium has the true index pattern in a first portion of the disk medium and also untrue index patterns of servo information in a predetermined number of second portions in proximity to the first portion along a track direction. The true index pattern and the untrue index patterns form a predetermined sequence.

Abstract: A method for detecting a frame edge in a servo stripe on a length of magnetic tape. The method includes converting an analog signal to a digital signal and detecting a change in digital signal frequency at a frame edge. A detection signal is generated in response to the detected frequency change.

Abstract: Various data storage formats help to efficiently locate, read, and write user data stored on magnetic tape media. A tape is formatted by writing multiple segment-headers, free from any interleaved access of user data Adjacent segment-headers are spaced by a predetermined interval to define multiple data storage segments. Segment-headers all contain a unique key, which is copied into a key index to identify valid segments. After formatting, normal tape accesses can be performed. Without erasing any old headers or data, a new formatting scheme can be established by writing new segment-headers on the tape. The new segment-headers include a new unique key, replacing the previous key in the key index. Previous segment-headers stored on the tape are ignored, since they lack the updated key. Segments may be selectively grouped to provide independently addressable partitions. Mapping between segments and partitions can use a fixed relationship (e.g.

Abstract: A supplied time code is multiplied to generate detailed time data. The detailed time data are latched at a given time in an input signal. The latched time data are converted into converted time data having a given data format. The converted time data are recorded in the same transmission path as the output signal.

Abstract: A method for constructing and processing a data address mark positioned in a data track of a magnetic disk immediately preceding a data region storing user data to establish synchronization requested for reading user data from the magnetic disk. The method includes recording of the data address mark in at least two different recording locations of the data track; and when one data address mark recorded in the different recording locations of the data track is normally detected to establish synchronization requested for reading user data from the magnetic disk, regarding the one data address mark as an effective data address mark of a corresponding data region.

Abstract: A method and apparatus for generating addresses. The present invention provides for fast generation of a series of addresses in an array where the series comprises a column or diagonal of the array, such as for layered ECC code words in CD-ROM. Whereas each address is computable individually using multipliers and modulo circuits, the present invention operates on the series of addresses as a whole, forming a dependence between successive addresses. The dependence is separated into multiple address indices that may be summed together for the desired address. The present invention is thus able to generate a series of addresses by accumulation processes requiring only selection of the appropriate increment value and addition to a previously stored address index value. Address generation throughput is increased with savings in layout area and power.

Abstract: Disclosed is a magnetic tape media having addressing data information superimposed on prerecorded track following servo information. The servo information is recorded in magnetic flux transition patterns defining at least one longitudinal servo track. A servo burst pattern of at least two repeated pairs of non-parallel magnetic flux transitions is provided, at least one of which transitions is slanted or otherwise continuously longitudinally variable across the width of the servo track. At least two transitions of the repeated pairs are shifted longitudinally with respect to other of the transitions, the shifted transitions comprising the superimposed addressing data information.

Abstract: A gray code decoding circuit of a hard disk drive includes a servo pattern area, a data pick-up device, and a pattern detecting device. The servo pattern area has data recorded as a gray code. The data pick-up device detects the recorded data, converts it into encoded read data, and outputs the encoded read data. The pattern detecting device detects a position of the servo pattern area in response to the encoded read data and outputs a reference pulse. The gray code decoding circuit also contains a gray window generating device, a synchronous signal generating device, a gray code extracting device, and a gray-binary converting device. The gray window generating device divides the encoded read data by a division ratio, converts the divided encoded read data into gray data, outputs the gray data, and generates a first synchronous signal after counting by a system clock to a first value. The synchronous signal generating device outputs first and second window signals in response to a second synchronous signal.

Abstract: The address of each track in a disk drive system is expressed in Gray code, and an appended bit of information is added to the Gray code, associated with the least significant bits thereof, the value of which is determined by the values of the most significant bits of the Gray code. The value of this appended bit is the same from Gray code to successive Gray code, as long as there are no changes in any significant bit between successive Gray codes, but the appended bit changes value when there is a change in a most significant bit between successive Gray codes.

Abstract: A data storage system is disclosed that is capable of performing a double check on data read from a storage media to determine whether the data is the data desired by a requesting host computer. If the data is not the desired data, the system discards the data before it reaches the host. The data storage system uses a randomizer unit having a variable initialization value. The initialization value is based upon the address of the data storage location being accessed by the host. If the initialization value used to read a piece of data is different than the value used to write the data, uncorrectable data errors result and the data is discarded.

Abstract: When writing user data D, the user data D is stored in a register 46, and using both the user data D and the sector information (ID) of the user data D, an error correction code ECC is generated by an ECC generation algorithm Ar. A stored information Rw made up of the user data D and the generated ECC is written on a disk. In the reading, the user data Dr of a read record Rr is temporarily stored in the register 46, and an ECC check algorithm is executed. This ECC check is executed for combined data of the user data Dr and its position information. When any error is found in the position information portion in the combined data, the user data is determined that the read user data is wrongly addressed. When an error is found in the user data Dr portion, the user data is corrected by ECC and the corrected user data is output.

Abstract: A method of generating data sector pulse in a magnetic disk drive includes the steps of servo-writing a bit of index pattern information corresponding to each servo sector in an index area of a servo area on the magnetic disk by a predetermined rule, mapping a data sector pulse timing value with respect to a representative frame of each zone in an inside storage by changing the frame number of relevant zone according to the characteristic of each zone, and reading a sector pulse timing value with respect to a predetermined sector of a predetermined track from the inside storage by deciphering the index pattern information read from the track according to the rule and loading the read result in a gate array for generating the data sector pulse.

Abstract: A tape recording medium with slant tracks formed in two longitudinal areas above and below a center line on the recording medium, wherein the slant tracks each include subcode data at a midportion of each track with two control data areas on either side of the subcode and two data areas on the outboard sides of the control data areas. The data areas can include audio data, video data, or computer data or a mixture thereof and the control data provides information specifying the kind of digital data that is recorded for use in reproducing.

Abstract: A circuit for variably adjusting a data detection level for processing a read signal picked-up from a magnetic disk.

Abstract: Apparatus and methods are provided to prevent writing and reading at an incorrect position and seeking to incorrect position. A servo address is written in a servo burst and loaded into an error correcting code (ECC) generator for generating write positioning ECC check bytes. The write positioning ECC check bytes are written at the end of the written servo address in the servo burst. When customer data is to be written, the written servo address and write positioning ECC check bytes are read and loaded into the ECC generator to determine whether the writing position is correct. Then the servo address or logical block address (LBA) is preloaded into a second error correcting code (ECC) generator and the customer data is written and loaded into the second error correcting code (ECC) generator for generating data and read positioning ECC check bytes. The data and read positioning ECC check bytes are written at the end of the written customer data.

Abstract: Separate servo parameter values are combined into a single servo parameter value having a bit length shorter than the total bit length of the separate parameter values. The combined parameter value is then stored in a servo field on a storage disk. By storing the shorter combined parameter, a given amount of servo information can be stored in a smaller space on the disk, thereby reducing overhead. In one embodiment, servo parameters are added together to create the combined parameters. In another embodiment, an equation is provided for creating the combined parameters, that results in a relatively large numerical distance between combined parameters in adjacent servo sectors on a track of the storage disk. The combined parameters stored on the disk can be used, for example, to check the accuracy of software position estimators in the disk drive.

Abstract: A method of recording an information signal on a recording medium. The method includes recording of first flag indicating an absolute address being continuous without overlapping, second flag indicating the absolute address having a probability of discontinuity without overlapping, third flag indicating the absolute address having a probability of overlapping, and fourth flag indicating the absolute address being absent. And one of the first through fourth flags is recorded with the absolute address.

Abstract: A single clock cycle adaptive data compressor/decompressor with a string reversal mechanism is described which can perform data compression and decompression at the rate of one uncompressed symbol per clock cycle. The LZW data compression algorithm has been improved for use in this data compressor. The compressor builds a string table as the data is received. Each string within the table is made up of the address within the table of the longest previously seen matching string and the one character that makes this string different. This data compressor/decompressor utilizes a content addressable memory to store the string table. This content addressable memory allows the compressor to store the current symbol string in a table while that same string table is simultaneously searched for the current string. During decompression the characters within a symbol string are output in reverse of the order in which they were input.

Abstract: A memory medium has a plurality of tracks arranged in a plurality of sectors with each track sector having a format which does not include header fields identifying sectors or sector defects or defect management procedures. Track management apparatus identifies the track sector currently confronting a transducer; the track management being based on sector pulses (in the case of a dedicated servo system), or being calculated based on track information, an index pulse and data wedge information from previous wedges (in the case of embedded servo systems), or being derived from a lookup table. To accommodate sector defects, a defect bank contains the identity and type of each defective or spare sector.

Abstract: The present invention provides a hard disk drive that employs a plurality of data recording disks. According to a first embodiment, one of the data recording disks provides first and second recording surfaces that each exhibit specific servo patterns. The first recording surface includes first servo sectors with first burst regions positioned within each one of the first servo sectors. Each one of the first servo sectors has a first full gray code recorded outside the corresponding first burst regions. The second recording surface includes second servo sectors with second burst regions positioned within each one of the second servo sectors. Each one of the second servo sectors has a second full gray code recorded within the corresponding second burst regions and no gray code recorded outside the corresponding second burst regions. The remaining data recording disks each have recording surfaces with the same servo pattern as the second recording surface.

Abstract: A servo address is encoded in a disk drive system having at least one disk for storing data. A servo address associated with a sector in a track, or cylinder, on a surface of a disk and comprised of a sector number, a track number, and in multiple disk systems, a head number is encoded into the encoded servo address. Encoding the servo address saves disk storage space because the encoded servo address uses fewer bits than a conventional servo address while still enabling the disk drive system to locate positions on the disk.

Abstract: A gray code is provided for use with disk servo track identification encodement that preserves the gray code property of only a single digit changing state between two numbers in the code sequence and also preserves magnetization between code numbers while only requiring a single bit for encoding each code value by recording a single pad bit before the gray code bits. By proper selection of the sign of the pad bit and the gray code numbering sequence, the gray code encodement scheme uses n+1 code bits for an n-bit gray code. The efficiency of the gray code encodement can be enhanced by splitting the track identification number to be recorded into multiple fields and then recording only the low order bits sufficient to identify a track within the maximum estimated error of the servo head on every track and otherwise alternating the high and low middle order bit fields with the low order bit field. A run-length limiting feature also can be provided.

Abstract: A rate 5/7, d=0 channel code encodes a Gray code servo track address into channel data recorded on a magnetic disk; a PR4 sliding threshold Viterbi sequence detector detects the recorded servo track address upon read back; a cost effective d=0 decoder decodes the recorded servo track address into its Gray code representation; and a 1/1+D filter decodes the Gray code track address into its binary representation. Detecting the servo data with a PR4 Viterbi sequence detector, which is already provided in a read channel for detecting user data, increases the data density of the storage system. The cost and complexity of the decoder is reduced by encoding/decoding the Gray code track address in sections of five bits.

Abstract: A magnetic disc storage system includes a rotating magnetic disc and a read/write transducer positioned proximate a recording surface of the magnetic disc for reading and writing information on the recording surface. Data stored on the recording surface is altered based upon the address of the data. During readback, a pseudorandom number generator receives a desired address as a seed input and provides a pseudorandom number output. An XOR gate provides an XOR output in response to the pseudorandom number output and the readback signal from the read/write transducer. An error detection circuit provides a decoded data output and an error flag output in response to the XOR output. An error during readback indicated by the error flag output is indicative of an incorrect address of the readback signal in comparison to the desired address. During a write operation, data is provided to an error detector encoder circuit which provides an encoded data output to an XOR gate.

Abstract: A disk drive system for a constant density recording (CDR) format disk has a microprocessor which generates CDR words from split values stored in a ROM. The CDR words indicate how embedded servo sectors split data sectors into data fields. In one embodiment, during a seek to a track, the microprocessor stores in a data buffer the CDR words for requested data sectors on the track. Alternatively, track CDR tables are stored in the data buffer during start-up and altered during a seek. A disk sequencer reads CDR words from the data buffer into a FIFO buffer as required to locate splits in data sectors. Alternatively the microprocessor writes the CDR word directly into the FIFO buffer. Typically, the microprocessor writes CDR words for a data frame, into the FIFO buffer, during a servo burst preceding the data frame, but the microprocessor can wait two or more servo bursts before writing CDR words for two or more data frames. Data transfer for each requested data sector is initiated by a sector pulse.

Abstract: A storage media for linear, serpentine recording is pre-formatted for data storage operations by recording partition format information in a single pass along the length of the storage media by recording partition format information for all storage media tracks at regular partition intervals defined by index locations alternately in both storage media directions before moving the storage media to the next partition interval. At each index location, partition markers are recorded in successive parallel tracks first in one media direction and then the other until markers are recorded across the entire width of the storage media. The steps of moving to a next partition index location, recording partition information in successive parallel tracks in first one direction and then the other, and moving to a next index location one partition length away, are repeated until all partitions of the storage media are pre-formatted.

Abstract: An intelligent disk drive includes a controller which embeds user data address information into error correction code check symbols written to the data storage disk. The address information is not written to disk, but address errors are detected by decoding the error correction code check symbols during read operations. Disk space is saved while maintaining robust address error detection.

Abstract: A magnetic disc apparatus employing a constant-density recording type and a magnetic disc driver for accessing data thereon. The magnetic disc apparatus comprises a plurality of tracks extended in a circumferential direction on the magnetic disc apparatus surface; a plurality of servo and data information areas which are provided in the circumferential direction of each track; a WID (wedge identification) field for recording the ID for data sectors positioned in one data information area, the ID being recorded in only one interval for each data information area; and a PID (pseudo identification) field positioned in front of each data sector and having an interval corresponding to transfer time of the PID (i.e. the ID of a corresponding data sector) generated from a WID field during access of the magnetic disc apparatus.

Abstract: In a magnetic disk drive of the type using data erase portions as address marks, an address mark detection system has an address mark detecting circuit and a read data masking circuit. The detecting circuit, monitoring a read data signal, becomes active on detecting a data erase portion whose duration is shorter than a predetermined period of time for address mark detection. The detecting circuit is cleared on detecting a data input. The masking circuit, receiving the read data signal, masks any suitable number of read data pulses input immediately after the detecting circuit has been cleared. As a result, even when noise is introduced in the data erase portion, the system prevents the resulting false read data pulses from being output.

Abstract: A coding method for an information recording/reproduction apparatus and a recording medium, comprising the step of setting a second code bit of a second track adjacent to a first code bit of a first track in the direction perpendicular to a track to "0" or "nonmark" when the first code bit of the first track is "1" or "record mark.", wherein a first coding rule for obtaining a first code bit on an odd track and a second coding rule for obtaining a second code bit on an even track are used and a second bit adjacent to a first bit in the direction perpendicular to a track is set to "0" or "nonmark" by the second coding rule when the first code bit is "1" or "record mark".

Abstract: A format for embedded servo track identification fields in rotating disk data storage units such as magnetic disk drives. The present invention uses the concept of tri-bits (i.e., three code bits per logical bit) to encode track identification information in servo wedges of embedded servo disk drive systems. More specifically, two particular sets (and their equivalents) of tri-bit codes have been discovered to have optimum characteristics for providing a phase coherent encoding of a Gray code that is simple to translate into straight binary code. The properties of such tri-bit encoding limit error propagation to a single bit, which allows for very reliable track identification during movement of a head transducer across tracks (i.e., "seeks"). A full range of Gray scale codes is available since more than two consecutive logical "0"s can be reliably decoded when encoded using such tri-bits.

Abstract: An error correction apparatus and method corrects an error burst occurring in the header information of a sector stored on a rotating magnetic storage medium, particularly sector identifying information. The apparatus (1000) comprises both a header correction subsystem (1060) for performing error correction upon the header information and a data correction subsystem (1075) for performing error correction upon the user data information. The header correction subsystem (1060) comprises a header correction unit (1250) which receives the header information from the medium and which generates an error pattern over the header information. A header register (1252) receives and stores the header information from the medium. The error pattern and the header information stored in the header register are used to obtain corrected header information.

Abstract: A servo address is encoded in a disk drive system having at least one disk for storing data. A servo address associated with a sector in a track, or cylinder, on a surface of a disk and comprised of a sector number, a track number, and in multiple disk systems, a head number is encoded into the encoded servo address. Encoding the servo address saves disk storage space because the encoded servo address uses fewer bits than a conventional servo address while still enabling the disk drive system to locate positions on the disk.

Abstract: An available recording capacity is determined from various factors such as the remaining recording capacity of a tape and the length of insert-recording time, and the amount of information to be recorded is also determined. On the basis of the information thus obtained, the compression ratio of variable-length coding is controlled so that information to be recorded can be reliably accommodated into an available recording capacity, whereby information of any time length can be recorded in a recording area of desired length. In addition, it is possible to prevent a problem such as destruction of another recording.

Abstract: A no-ID zone-bit-recording sectored servo data recording disk drive system is described wherein track seek time is substantially reduced by storing only partial cylinder address on each servo sector of each track. According to the system and method described herein, a cylinder address is divided into high order bits, middle order bits, and low order bits. The low order bits is stored on each servo sector of each track. The high order bits is stored only on even number servo sectors and middle order bits is stored only on odd number servo sectors. During the seek operation, as the head passes over the tracks toward the desired track, the partial cylinder address stored on odd and even numbered servo sectors on each track is retrieved and stitched together to form a complete cylinder address. The completed cylinder address is then compared with the desired cylinder address to determine whether desired cylinder is reached or not.