Abstract: An optical disc and a method and apparatus for recording digital data streams and management information on the disc, are provided. The method includes recording a digital data stream including at least one predetermined-sized unit, each unit carrying header information and at least one packet, the header information being represented in at least one header entry, selectively appending an additional header entry based on whether a number of the at least one header entry corresponds to a number of the at least one packet, and recording an indication information that indicates whether or not the additional header entry is appended.

Abstract: Recorded on the recording medium (BD-ROM) is an AV stream that is obtained by multiplexing a video stream and one or more audio streams. MOVIE objects are scenarios showing playback procedures of video data described using playback device-oriented commands. In addition to the MOVIE objects, enhanced-mode scenarios (Java and WebPage objects) are also recorded on the recording medium. These enhanced-mode scenarios, each of which is described in the Java language or a markup language, show control procedures with respect to playback devices. The Java and WebPage objects are capable of taking over register setting values set by MOVIE objects, and extracting parts of video data played by MOVIE objects.

Abstract: A servo field preamble detector includes an upsampling module that generates a plurality of upsampled read samples by upsampling a read signal by an upsampling factor. An interpolation filter module generates a plurality of interpolated read samples from the plurality of upsampled read samples. A peak detection module identifies a plurality of peak samples from the plurality of interpolated read samples. A magnitude estimation module generates a magnitude estimation signal from the plurality of peak samples. A comparison module compares the magnitude estimation signal to a magnitude threshold and asserts a servo preamble detection signal when the magnitude estimation signal compares favorably to the magnitude threshold.

Abstract: A method and an apparatus for copying data of a disc drive are provided. The method includes: determining whether the first disc drive has a predetermined jumper pin connection by identifying which of a plurality of jumper pins in a jumper block of the first disc drive are connected, the jumper block being used to determine an operation mode of the first disc drive; transmitting a copy command from the first disc drive to the second disc drive if the first disc drive has the predetermined jumper pin connection; and copying data recorded in the first disc drive to the second disc drive in response to the copy command. Accordingly, it is possible to copy data recorded in a first hard disc drive (HDD) to a second HDD without the aid of an additional host.

Abstract: An output of a magnetic head changes depending on the environmental temperature of a magnetic disk. In particular, under cold temperature conditions, an output of the head largely decreases mainly due to an increase in coercivity of a magnetic recording medium, which degrades an error rate. In one embodiment of the invention, sense-current optimization processing of a magnetic disk drive comprises the steps of: measuring the environmental temperature; and after a sense-current value which is set from the viewpoint of the reliability of the magnetic head is defined as an upper limit, finding out a sense current Is that can achieve the best error rate (BER) at the temperature. While changing a value of the sense current Is inside the magnetic disk drive, an error rate is measured. Then, a sense current Is_opt at which the best error rate properties are achieved is selected as a new set value.

Abstract: A disk drive is disclosed including a disk having a plurality of data tracks, wherein each data track comprises a plurality of data sectors and a plurality of servo sectors, and each servo sector comprises a plurality of servo bursts. A data path comprising a data decoder decodes a data read signal generated as a head passes over the data sectors, and a servo path demodulates a servo read signal generated as the head passes over the servo bursts. The servo path comprises a low pass filter operable to extract a low frequency component from the servo read signal, wherein the low pass filter does not operate on the data read signal. The servo path further comprises a subtractor operable to subtract the low frequency component from the servo read signal to generate a servo burst signal, and a servo demodulator operable to demodulate the servo burst signal.

Abstract: There is provided an information reproduction apparatus that can suppress degradations in the qualities of reproduced data and timing from due to interpolation errors when performing interpolation timing recovery, and that can avoid degradation in the stability of the system due to an increase in the timing recovery loop delay. An information reproduction apparatus (100) for reproducing data and timing from an analog signal including data information and timing information is provided with an expected value generator (106) for outputting plural expected values, and a maximum likelihood detector (107) for outputting data that corresponds to a sequence of the highest likelihood with an output sequence of an A/D converter among the plural expected value sequences, at the timing of a second clock.

Abstract: A system and method are disclosed for controlling an inventory of point-of-care diagnostic devices. The inventory includes a main inventory and at least one subinventory. Each device has an ambient temperature shelf life. Data associated with the devices is entered, including: the current quantity and predetermined minimum quantity of devices in the main inventory; and the current quantity and predetermined minimum quantity of devices in the subinventory. A first timestamp is associated with each device when the device is transferred from the main inventory to the ambient temperature subinventory. The first timestamp is compared to a second timestamp prior to use of the device to determine whether the device's ambient temperature shelf life is exceeded. The current quantity of devices in the subinventory is updated in response to an event that causes a change in the current quantity of devices in the subinventory.

Abstract: Methods and apparatus to provide dynamically biased write drivers for hard disk drive applications are described. According to one example, a hard disk drive write system includes a drive signal generator to receive data to be written to a hard disk drive platter and to generate drive signals including a boost signal. A drive circuit is configured to receive the drive signals and to generate currents for output to the transmission line based thereon, wherein the currents include a boost current. A variable bias circuit is configured to detect the boost signal generated by the drive signal generator and to vary a bias signal provided to the impedance matching circuit based on the detection of the boost signal. In such an example arrangement, the impedance matching circuit matches impedances between the drive circuit and the transmission line in response to the bias signal provided by the variable bias circuit.

Abstract: A gain setting apparatus that externally performs setting of a magnetic disk apparatus before shipment causes a servo data gain setting unit to set a servo data gain for a preamplifier. The gain setting apparatus then causes a core deviation correction processor to set the servo data gain as a provisional user data gain, so as to perform core deviation correction for correcting positional misalignment between a read core and a write core. Further, the gain setting apparatus causes a user data gain setting unit to set the user data gain for the preamplifier.

Abstract: Disclosed is a reproducing apparatus to reproduce reproduction data at a speed different from a speed at a time of recording of the reproduction data, the recording apparatus including: a storage section to store the reproduction data; a primary reproducing plan producing section to produce a primary reproducing plan ranging from present time to future, according to the reproduction speed different from the speed at the time of recoding the reproduction data; and a secondary reproducing plan producing section to modify to the primary reproducing plan by solving an optimization problem based on the primary reproducing plan produced by the primary reproducing plan producing section, so as to produce a secondary reproducing plan ranging from the present time to the future.

Abstract: In a system for reproducing AV information from a recording medium, such as a DVD, not only are usual titles reproduced, but also related information relevant to specific stream information is acquired easily by making use of resources on a computer network. In a reproducing system with the function of reproducing the title information recorded on a DVD and displaying it on the screen of a display section, when the user clicks a Web mark on the screen, the CPU links to a Web server on the Internet via a modem and accesses the Web page related to the stream information on the screen. At that time, the related Web page is the selected information conforming to parental information, or attribute information, set in the system.

Abstract: An optical disc used for storing content includes a theft control area selected to render the disc unreadable. The disc must be exposed to radiation of a specific wavelength before it can be read by a regular device. The theft control area may include an area that contains data that instructs the device not to read the disc. This area includes a coating that changes its optical characteristics when exposed to the radiation. The material could be radiochromic or thermochromic. Alternatively, the theft control area includes an RFID device that includes an element that is radiation sensitive. In this embodiment, when the disc is irradiated, the element changes its electrical characteristics.

Abstract: For a reproduction of optical sound information in a double variable-area track (DZ) an optoelectronic converter device scans the optical sound track of a film. The converter device generates a digital image signal for buffer storage in the memory of a program-controlled data processing device. The data processing device derives the profile of the two edges of the double variable-area track from data values of the buffer-stored image signal. Audio data for a sound reproduction are generated using data about the edge profile determined.

Abstract: A method and system for reserving future purchases of goods or services. A server network device provides to a client network device via a computer network, a list of available goods or services including plural electronic options with associated option fees for the goods or services. The plural electronic options include electronic option terms established by one or more suppliers who can supply the goods or services. An option fee is associated with a reservation price to purchase desired goods or services at a desired future. Electronic option terms for a selected good or service for a desired supplier who can supply the selected good or service are provided. A purchase of an electronic option for an option fee for a desired good or service for a desired supplier is accepted on the server network device. The purchase of the electronic option is accepted according to electronic option terms established by the desired supplier.

Abstract: A system and method are disclosed for controlling an inventory of a plurality of point-of-care diagnostic devices. The plurality of devices includes at least one type of device. Each device is configured to perform at least one sample analysis. Each device has a usable lifetime. The inventory includes a main inventory and at least one subinventory. The inventory control system comprises a data input interface for entering data associated with the devices and a data output interface for displaying data associated with the devices. A memory stores data associated with the devices and stores steps of a computer program to automatically update the current number of devices in the at least one subinventory in response to an occurrence of an event that causes a change in the current number of devices in the at least one subinventory. The inventory control system comprises a processor for accessing the memory to execute the computer program.

Abstract: A fully synchronous longitudinal position (LPOS) detection system is provided for improving the reliability of servo channels in tape systems. The system is based on the interpolation of the servo channel output signal, which is sampled by an analog-to-digital converter (ADC) at a fixed sampling rate, using a clock at a nominal frequency, so that interpolated signal samples are obtained at a predetermined fixed rate, independent of tape velocity. This predetermined fixed rate is defined in terms of samples per unit of length, as opposed to samples per unit of time, which is the measure of the ADC sampling rate. The resolution with which the servo channel signal is obtained at the interpolator output is thus determined by the step interpolation distance.

Abstract: A failure analysis system of a logic LSI incorporates software therein. The analysis system includes a function to record the terminal signal information of said logic LSI in synchronization with a clock and a function to reproduce said recorded terminal signal information in synchronization with the clock. The analysis system further includes a function to compare said reproduced terminal signal information with the terminal signal information of a normal logic LSI.

Abstract: When the data recording is performed on a magnetic tape in various recording densities, information relating to the recording density (recording-density related information) is recorded in the data recorded on the magnetic tape. Accordingly, recording and reproduction can be properly managed by referring to the recording-density related information, even if data in various recording densities are recorded on the same magnetic tape. Further, when the recording density is altered, the drive apparatus side switches over the recording density in accordance with the quality of recording data. Thus, in the case where the data writing is not possible due to a recording error, the recording density is switched over to a lower recording density to record the data without an error, and therefore a higher flexibility is provided to a data format to be recorded on the magnetic tape.

Abstract: A drive control apparatus receives an instruction from an upper unit, to mount a predetermined medium onto a predetermined drive unit. If a combination of the predetermined medium and the predetermined drive unit is determined as inappropriate, the drive control unit replies to the upper unit that the predetermined drive unit cannot be used. A combination of a medium and a drive is appropriate if both, the medium and the drive are suitable for any one of encrypted and unencrypted data.

Abstract: To provide an integrated information processing unit that is capable of producing images and sounds of high quality. It includes a control unit, information processing units, and a merge unit. Each of the information processing units includes a counter for synchronization purpose. The information processing units performs a predetermined processing based on the measured value obtained by the counter for synchronization purpose. The control unit simultaneously provides a trigger of measurement of synchronization clocks to all counters for synchronization purpose and individually provides a reset signal to the counters for synchronization purpose which the reset signal is for initializing the measured value obtained by the counters for synchronization purpose. The merge unit merges information processed by the information processing units according to the unit of output (in frame) of, for example, a display device.

Abstract: A disk drive is disclosed comprising a disk for storing data, the disk comprising a public area for storing plaintext data and a pristine area for storing encrypted data. The disk drive comprises a head for reading the encrypted data from the pristine area of the disk, and a control system for controlling access to the pristine area of the disk. Authentication circuitry within the disk drive is provided for authenticating a request received from an external entity to access the pristine area of the disk and for enabling the control system if the request is authenticated. The disk drive further comprises a secret drive key, and decryption circuitry responsive to the secret drive key, for decrypting the encrypted data stored in the pristine area of the disk.

Abstract: A tape drive and method of identifying write velocity during reading are provided. When a track is being read, a lead-in code of the data signal is processed prior to determining the data stream. The lead-in code identifies the velocity with which the track data were written. The equalization/detection channel is adjusted based on the identified velocity to compensate for write channel transfer function variation. The lead-in code is coded in a way that is reasonably immune to write channel transfer function variation such that the lead-in code is comprehended prior to adjusting the equalization/detection channel.

Abstract: A digital data reproducing apparatus includes, a read head for reading data from a recording medium, an analog-to-digital converter for converting the data read by the read head into digital data, a memory for storing the digital data converted by the analog-to-digital converter, a phase control circuit for controlling phase of the digital data, and off-track detector for detecting off-track of the read head from a track on the recording medium. In the apparatus, storing operation to the memory is controlled based on output signal from the off-track detector and output signal from the phase control circuit.

Abstract: An audio or other program signal is modified to provide protection against copying on a magnetic tape recorder. The signal from a source (10) is amplified (16) and then subjected to Fourier analysis (11) to determine the signal amplitude in a plurality of subbands across the audible range. The subband containing the component of greatest magnitude is selected on an adaptive basis and applied to a stored psycho-sensorial model (12), which determines the maximum amplitude of interference which can be masked by the selected subband. An anti-copy signal is generated (14) by complex division of the desired interference by a stored representation of the response of a tape recorder (13).

Abstract: A detector detects, in read data, a servo address mark of a type indicated by a register. Every time a SAM is detected during a self servo process, a CPU carries out tracking control in accordance with corresponding servo data. The CPU causes a head to write a corresponding type of additional servo data item in a disk at a position offset from the position of servo data containing the detected SAM, by a predetermined distance in a circumferential direction of the disk. Every time sets of servo data, each consisting of various types of data items, are written in the disk, the head is moved by a predetermined pitch in a radial direction of the disk.

Abstract: A laminated perpendicular magnetic recording medium comprises a non-magnetic substrate and at least a pair of polycrystalline, vertically stacked, spaced-apart perpendicular magnetic layers supported thereon, wherein each of the magnetic layers has substantially the same preferred out-of-plane crystal growth orientation and the grains of at least two of the magnetic layers are vertically uncorrelated with each other.

Abstract: Method and apparatus accomplishing an OPC (optimal power calibration) at a test area secured in data recording area of a writable optical recording medium and detecting an optimal writing power appropriate to the test area. The optimal writing power detecting method searches for a marginal area adjacent to a data section recorded on an optical recording medium, records test data on the marginal area discovered in the searching step while changing a writing power; and reproduces the test data recorded on the marginal area and determines an optimal writing power based upon the characteristics of the reproduction signal. The method and apparatus can reduce time required to move an optical pickup inward and outward to accomplish the OPC operation, from a recording request to practical data recording, while enhancing writing characteristics, since an optimal writing power is obtained from a test area close to the area for recording input data.

Abstract: A PLL circuit is disclosed which extracts phase difference information of a high S/N ratio from a readout signal uses the phase difference information for PLL control. An A/D converter samples the input signal to produce a digital signal. A pattern string detector identifies a type of an input pattern string formed from a plurality of successive sample values successively outputted from the A/D converter and outputs pattern string identification information which indicates an identification result. A phase difference generator outputs phase difference information which indicates a phase error of the output of the A/D converter based on the pattern string identification information and the output of the A/D converter. A loop filter, a D/A converter and a voltage controlled oscillator generate a clock signal from the phase difference information to control the sampling timing of the A/D converter.

Abstract: An information management apparatus capable of reliable management of distributed information and an information providing system employing the same information management apparatus has a main information reproducing system for reproducing main information recorded in a given recording medium; and a reproduction management system for managing the main information reproducing system for reproducing the main information. A receiver is provided with a unit for recording distributed information and control information limiting the number of main information reproducing cycles on a recording medium, and a main information reproducing system provided with a reproduction disabling function for limiting the reproduction of main information.

Abstract: The present invention relates to an information providing system. More particularly, this invention relates to an information management apparatus capable of reliable management of distributed information and an information providing system employing the same information management apparatus. The information management apparatus comprises a main information reproducing means for reproducing main information recorded in a given recording medium; and a reproduction management means for managing the main information reproducing means for reproducing the main information. The present invention provides a receiving means provided with a means for recording distributed information and control information limiting the number of main information reproducing cycles on a recording medium, and a main information reproducing means provided with a reproduction disabling means for limiting the reproduction of main information.

Abstract: A data recording and reproducing apparatus capable of easily obtaining information which has few dropout and is necessary for variable speed reproduction at the time of variable speed reproduction. An image group dividing unit divides input image data into a plurality of image groups on a unit image basis, thereby forming plural divided data. After the formed divided data is temporarily stored into an image data temporary storing unit, the divided data is outputted as image data which is a data stream of the divided data in a predetermined image unit to a disk array apparatus via an HDD output interface unit. Each disk array apparatus records the divided data into HDDs so as to periodically change the relation between the HDDs and the groups of data to be recorded to the HDDs in a predetermined pattern.

Abstract: Video signals are recorded according to the number of tracks corresponding to the broadcasting system for each basic unit. When control signals are recorded on a magnetic tape in the longitudinal direction, the duty ratio of the control signals for every N tracks recorded for each basic unit has a value different from that of the duty ratio of other control signals. At the time when the magnetic tape 1 is reproduced CTL signals are obtained by forming waveforms of the reproduced amplified outputs by means of a waveform formation unit 6. A CTL signal duty ratio determination unit 9 detects the border of a frame in accordance with the duty ratio. A broadcasting a system determination unit 10 determines the broadcasting system based on the counting result of the CTL signals during one frame that has been counted by the CTL signal counting unit 9.

Abstract: A parallel read/write circuit for use with a plurality of transducer head assemblies and method of operation thereof. The parallel read/write circuit includes a parallel read/write cache, e.g., a bidirectional parallel-serial converter buffer in one advantageous embodiment. A byte-to-bit disassembler, coupled to the parallel read/write cache, receives parallel data from the parallel read/write cache and transmits each bit of the parallel data to a separate transducer head assembly, where each bit of the parallel data is written onto a different disk surface of a recording medium at substantially the same time. In an advantageous embodiment, the byte-to-bit disassembler is a parallel in/parallel out shift register.

Abstract: A signal transmission method applicable to prevention of modification or alteration of the playback mode information, such as copying management information or charging information. The playback mode information form a terminal 15P is data-converted for ciphering by a playback mode information appendage circuit 14 in a header appendage circuit 13 responsive to the key information from a terminal 15K and the resulting information comprised of the data and the playback mode information is outputted. The reproducing side effects data conversion on the ciphered playback mode information for deciphering, by a playback mode information detection circuit 26 in a header separation circuit 25, using the key information from a terminal 27K, for taking out the original playback mode information at a terminal 27P.

Abstract: A digital data reproducing apparatus includes, a read head for reading data from a recording medium, an analog-to-digital converter for converting the data read by the read head into digital data, a memory for storing the digital data converted by the analog-to-digital converter, a phase control circuit for controlling phase of the digital data, and off-track detector for detecting off-track of the read head from a track on the recording medium. In the apparatus, storing operation to the memory is controlled based on output signal from the off-track detector and output signal from the phase control circuit.

Abstract: An apparatus and method that allow for the compatibility of data-storage disks with disk drives is provided. In an illustrative implementation, an exemplary disk drive for use on data storage disks reads the control logic sector of cooperating data-storage disks for a compatibility indicator. If the disk is compatible the drive performs read/write operations. If the disk is incompatible, the indicator is overwritten to ensure compatibility. From there read/write operations are allowed. The processing may be realized by machine instructions present in a control circuit of the disk drive.

Abstract: Method and apparatus for recording data on a magnetic recording medium and writing data to a computer bus in which the data is divided into words of a predetermined length, a signal is generated for each data word, having an amplitude which is representative of the value of the data word, and this signal is then recorded to the magnetic recording medium or written to the computer bus. Complementary method and apparatus is provided for reading the data from the magnetic recording medium and the computer bus.

Abstract: A recording disc has a lead-in area and a data area. A scrambled version of a SID code word is read out from the lead-in area of the disc. The SID code word represents a producer of the disc. The readout scrambled version is de-scrambled to recover the SID code word. The recovered SID code word is collated with reference SID code words to decide whether or not the disc is legitimate. Main information is read out from the data area of the disc when it is decided that the disc is legitimate. Readout of the main information from the data area of the disc is inhibited when it is decided that the disc is not legitimate.

Abstract: A disk drive comprises an actuator servo control system including at least one disk, an actuator structure comprising at least transducer head for writing and/or reading data from the disk and providing a transducer head position error signal (PES), and a servo compensator applying a servo control algorithm to the PES to produce a servo control signal. An adaptive elliptic notch filter controller is adapted to analyze the PES for a transducer head at a disk track radii, identify resonant disturbances present in the PES, select two adjacent resonant disturbances having first and second frequencies, ascertain coefficients of at least a fourth-order elliptic notch filter transfer function having first and second zero-notches with frequencies substantially at the first and second resonant frequencies, apply the at least fourth-order elliptic notch filter transfer function with the ascertained coefficients in the servo system to thereby substantially attenuate the selected adjacent resonant disturbances.

Abstract: In an essentially flat contour linear tape recording head, a nominal tape wrap angle exists at which reading signals from the magnetic tape ceases and/or commences. This nominal tape wrap angle can be easily determined by monitoring a prerecorded signal, such as the servo track signal, while the tape wrap angle is adjusted. When the signal ceases (or starts, depending upon the direction of adjustment) an initial position of the tape movement control device relative to the tape wrap angle is identified. At this initial position it is known that the tape wrap angle is at its nominal value, such as approximately 0.1°. Thereafter, the tape movement control device can be knowingly adjusted with a calibrated indicator to accurately and quickly achieve a desired final tape wrap angles.

Abstract: When an operator inserts a standard magnetic tape into the magnetic recording and reproducing apparatus and performs operation for bringing the apparatus into the play mode for checking X value, the tracking value varies in stages, and an external device or the magnetic recording and reproducing apparatus produces an envelope detected output having a value corresponding to an output from the rotary heads, samples an envelope detected output at predetermined positions within a single trace by the rotary heads in each tracking value, and executes a check of the preset value (X value) or a check of the linearity of the tracking value of the rotary heads.

Abstract: Recording/reproducing apparatus for recording/reproducing serial information stream of A/V signals comprising packets of information signals, such as MPEG Transport Packets, on/from a recording medium. The apparatus includes a time stamping unit for time stamping received information packets in accordance with a time stamping clock reference, a writing unit for recording the information packets in accordance with a write clock reference, and a reading unit for reproducing the information packets in accordance with a read clock reference. All clock references are derived from a single crystal clock reference. The read clock reference has a frequency equal to the frequency of the single crystal clock reference, this frequency being an integer multiple of the frequency of the write clock reference. The time stamp clock reference has a frequency derived from the single crystal clock reference by a digital counter.

Abstract: Disclosed is a headerless hard drive system that includes a head-disk assembly, a servo control logic, and a format calculator. The head-disk assembly includes a set of recordable disks for storing data. Each recordable disk having a plurality of tracks with each track having a plurality of servo wedges for dividing the track into a plurality of data frames. In this arrangement, one data frame is associated with one servo wedge and the tracks do not contain any header information that uniquely identifies the data frames in the tracks. The servo control logic coupled to the head-disk assembly to process the servo wedges for generating a signal that identifies a servo wedge being processed on a track. The format calculator is configured to convert the signal that identifies the servo wedge being processed to an associated sector number on the track.

Abstract: The present invention may be regarded as a disk drive comprising a disk with a reserved sector for storing a data-sector channel parameter, and a data sector for storing data. The disk drive further comprises a read channel circuit comprising a parameter register, and a non-volatile semiconductor memory (NSM) storing a reserved-sector channel parameter that is selected by using a parameter calibration procedure performed for the disk drive. A disk controller retrieves the reserved-sector channel parameter stored in the NSM, programs the parameter register with the retrieved reserved-sector channel parameter in order to configure the read channel circuit to recover the data-sector channel parameter stored in the reserved sector, and programs the parameter register with the recovered data-sector channel parameter so that the read channel circuit is configured to recover the data stored in the data sector.

Abstract: A data tape drive senses the ambient temperature and the relative humidity of the environment in which the tape drive is operating. The tension exerted on the data tape by the tape drive is then adjusted as a function of the temperature and/or humidity. When the tape is more rigid at low temperature/humidity, the tension is increased. At nominal temperature/humidity, a nominal tape tension is used. However, under elevated conditions a lower tension is utilized to avoid damaging the tape. The sensors also may be used to completely prohibit drive and tape operation when the tape drive is in an extreme environment that is beyond an acceptable design range. Tape acceleration profiles due to atmospheric conditions are changed based on the propensity of the tape to stick to the head.

Abstract: A circuit for use in a phase locked loop includes pre-computation blocks for phase error detector and loop filter functions, a selection block (or multiplexer) of these pre-computed results based on detected (or reference signal) signal, and on ambiguity zone detector deriving the pre-computation blocks.

Abstract: A magnetic disk drive data storage disk defines recording tracks divided into data sectors by narrow servo spokes. A data sector lying between servo spokes is recorded with user data encoded in accordance with a code having a predetermined distance and user data code rate. Each servo spoke of the recording area has at least one servo information field encoded in a wide bi-phase code pattern. The disk drive further includes a synchronous sampling data detection channel having a data transducer head positioned by a servo-controlled actuator over the recording track, a preamplifier for receiving electrical analog signals magnetically induced by the data transducer head from flux transitions present in at least the servo information field, a digital sampler for synchronously sampling the electrical analog signals to produce digital samples, and wide bi-phase decoding circuitry coupled to receive digital samples from the synchronous sampling data detection channel for decoding the wide bi-phase code pattern.

Abstract: A system, method, and article of manufacture for adaptive re-mapping of head addresses in a data storage device. A logical address received by the data storage device is converted into a corresponding physical address, such as cylinder or track, read/write head, and sector. The selection of the read/write head is then re-mapped by the data storage device to a more optimal selection. Thereafter, the desired operation can be performed using the physical address including the re-mapped selection of the read/write heads.

Abstract: The present invention relates to an information providing system. More particularly, this invention relates to an information management apparatus capable of reliable management of distributed information and an information providing system employing the same information management apparatus. The information management apparatus comprises a main information reproducing means for reproducing main information recorded in a given recording medium; and a reproduction management means for managing the main information reproducing means for reproducing the main information. The present invention provides a receiving means provided with a means for recording distributed information and control information limiting the number of main information reproducing cycles on a recording medium, and a main information reproducing means provided with a reproduction disabling means for limiting the reproduction of main information.