Abstract: A writing unit writes a first sync byte pattern SB1 to the head of data and writes a second sync byte pattern SB2 to the end of the data (DATA+ECC). When the first sync byte pattern SB1 is not detected, the data is stored into a memory, and after that, a reading unit reads out the second sync byte pattern SB2 in the memory. When the second sync byte pattern SB2 is detected, the reading unit reads out the data of a predetermined length DL in which a position that is preceding to the detecting position by only a predetermined data length (DL) is set to the head position from the memory and demodulates.

Abstract: A magnetic recording and reproducing apparatus arranged to use a magnetic tape. The apparatus operates to derive the current taken-up position of the magnetic tape from the signals that are proportional to the rotation frequencies of a capstan motor, a supply reel and a take-up reel. Only when the taken-up position is near the tape end, the apparatus activates LEDs (light emitting elements) for sensing the tape end and photo-transistors (light receiving elements), for sensing the tape end.

Abstract: A device that reproduces signals recorded on a recording medium includes a unit that forms a tracking error signal from pilot signal components recorded in the signal being reproduced. A controller controls the tracking error signal forming unit so that the tracking error signal forming unit operates under reduced power during part of the signal reproducing operation. The tracking error signal forming unit uses a digital filter and the controller controls the digital filter to vary its characteristics.

Abstract: An automatic calibration method for a read system in which data read by a head from a recording medium is demodulated using a partial response method which includes the steps of: storing at least one of a parameter relating to a bias current fed to the head and parameters necessary for data demodulation in the read system, for a plurality of operating conditions; and automatically calibrating the at least one parameter to a preset value suitable for an operating condition.

Abstract: A recording apparatus provided on, for example, a digital audio tape recorder or on a data storage device for correctly and reliably recording data. An ECC unit 23 appends the parity for error correction to recording data and transmits the resulting data to recording heads Hw1, Hw2, while recording the parity in a RAM 61. The recording data and the parity are reproduced from a magnetic tape 32 by magnetic heads Hr1, Hr2 and supplied to a subcode separation unit 45. A syndrome detection unit 62 detects the number of error corrections performed by parity by an error correction unit 46. A system controller 63 compares the number of times of error corrections to a threshold value and compares the parity read out from the RAM 61 to the parity from the sub-code separation unit 45 in order to detect if the recording data has been recorded correctly. If the recording data has not been recorded correctly, the system controller controls a recording/reproducing unit 30 for re-recording the same recording data.

Abstract: There is provided in an embodiment according the present invention, a signal processing device comprising detecting means for detecting a predetermined frequency component of the input signal; modulating means for modulating the input signal and supplying the modulated signal to a recording device; and switching means for supplying, in a first state, the output of the modulating means to the detecting means, and for supplying, in a second state, a reproduced signal to the detecting means from a reproducing device. With the aforementioned construction, the detection circuit that detects a predetermined frequency component included in the modulated digital signal can be used during recording as well as during signal reproduction, which greatly contributes to reducing the size and cost of the recording/reproducing device.

Abstract: An internetwork (such as the Internet) telephony system and method incorporating architecture and methodology which facilitates a high degree of scalability. The scalability provides improvement dealing with usage recording, usage pricing, billing account management, and fraud control. The scalability is achieved primarily by bundling of usage recording, pricing, authorization and billing practices in one logical database object which may be physically distributed. A predefined set of network elements are provided access to the database object to obtain authorization for a call along with limitations on the maximum cost or duration of the call for the particular account involved. The database object records usage statistics relating to the completed call, including pricing, and this data is available for virtually immediate billing. The database object provides to customers on a virtual real time basis the customer's usage statistics, including statistics for a call in progress.

Abstract: The present invention is a method to minimize the firmware overhead for multi-track transfers. To this end, the present invention provides a transfer control table. The table is used to manage sector defects or other transfer adjustments. Each entry of the table contains an affected PSA and a corresponding control instruction. The control instruction includes an action such as an interrupt/branch, take no action, skip the sector or skip the following indicated sectors. The interrupt/branch bit causes an preferably when the last sector of a track has been read or written. The table is either entirely generated at the same time or is generated to provide for a track transfer. In the latter case, the remaining table entries are generated during the platter revolution or the track seek. The method provides for minimum microprocessor intervention. To that end, the microprocessor is interrupted only at the end of the multi-track transfer.

Abstract: The present invention provides a disk drive, a load/unload unit, and a control method thereof which are capable of reliably unloading a head slider from a disk when power is turned off and enhancing reliability. A disk drive is equipped with a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving over the surface of the magnetic disk or to an evacuating position a head slider having the magnetic head, a ramp block, and a CPU/HDC (control means) for performing control of load and unload operations, speed control of the actuator mechanism, and control of an operation of reading or writing data from or to the disk. The CPU/HDC receives a specific command issued from the host immediately before power is turned off, and executes this command, then executes unload control, and notifies the host of command completion after the unload control has been completed.

Abstract: A method of managing information to be stored on a storage disc in a disc drive system to achieve improved system performance. Some of the data on the disc may be mirrored on the same surface of the disc to reduce latency and/or seek time. Compression techniques may be employed to limit reductions in the storage capacity of the disc. In another embodiment, data is preferentially stored on the outer tracks of the disc because system performance is greater when accessing outer tracks. Compression techniques may also be employed with this embodiment to limit reductions in the storage capacity of the disc. Compressed data stored on the disc may be transferred to another storage medium in its raw compressed form to reduce the number of instructions that would be required to transfer the data if it were decompressed before transfer.

Abstract: During retrieval of data from tape in a helical scan tape drive mechanism with a rotary head drum, movement of tape past the drum by a capstan is controlled to keep the tracks recorded on the tape in alignment with paths followed by the heads. A time interval is measured between occurrence of a drum position pulse generated at a specific angular position of the drum, and detection of reference signals included in the tracks (such as specific portions, with known bit patterns, of the data in the tracks). The capstan is operated to keep this interval equal to a set reference value. If a change in the reference value is required, such as at a transition between data recordings made at different times, the tape is moved at a slower than normal speed, and multiple measurements are made of the time interval as it cycles through a range of values in consequence of the changed tape speed. The mean value of these multiple measurements is used as the new reference value.

Abstract: A digital signal recording and reproducing method and apparatus for digitally recording and reproducing first and second signals in tracks on a magnetic recording includes an encoder and a recording unit. The encoder separately error-correcting encodes the first and second signals of a first and second type, respectively, to produce at least first and second inspection codes corresponding to the first and second signals. The first and second inspection codes have first and second lengths, respectively. The recording unit records the first and second signals and the first and second inspection codes in tracks of the magnetic recording medium so that the first and second signals and the first and second inspection codes are recorded in a track without a gap therebetween.

Abstract: The present invention provides a method and interface for browsing the internet using a telephone circuit having keys for generating DTMF codes. The interface includes a memory and a processor and is coupled to the telephone circuit and display. The interface receives a first DTMF code requesting access to the internet and, in response to the first DTMF code, loads a Web browser in its memory. The interface then receives a second DTMF code from the telephone circuit and converts the second DTMF code into a Web browser command using an interpretation protocol. The Web browser command is then executed using the interface, thereby enabling a user to access the internet via manual operation of the keys of the telephone circuit.

Abstract: A data storage disk drive array is synchronized using drives wherein each has an onboard oscillator assembly which is connected either for independent operation of each drive or synchronization of all or any selected drives of the array using a common or slave sync line that can supply an index signal to all or any portion of the drives of the array and is capable of using the oscillator assembly of any drive in the synchronized array as the source of the common precision index signal. The system can also be partitioned in subarrays with synchronization of the entire system, of individual subarrays or any mix of subarray combinations while retaining the capability for any drive of the system to function independent of the synchronization of any group of drives within the system.

Abstract: A tracking method enables a first read head (R1) and a second read head (R2) of a helical scan tape drive (30) to read non-native helical stripes, the non-native helical stripes being wider than native stripes. Read signals from the first read head (R1) and the second read (R2) head which are acquired from the non-native tracks are used to determine a correction value. The correction value is in turn used to control a relative position of the first read head (R1) and the second read head (R2) over the non-native helical stripes.

Abstract: A method and a device in which information is written on a medium and is read out, and which establishes whether the information read is sufficiently reliable, and in which so-called erasure information is used to establish the influence of media defects and other imperfections on the occurrence of errors in a transmission system. The medium is, for example, a hard disk containing one or more bad spots whose location can be accurately detected. The implementation of the method makes accurate and fast computation of the bit error rate possible.

Abstract: A method for operating a disk drive apparatus in the Idle Mode reduces power consumption while meeting non-operating shock and vibration specifications. This is achieved by operating the disk drive apparatus with the head in the loaded state with the disk rotating at a first rotational speed, unloading the head, and in Idle Mode, rotating the disk at a second rotational speed lower than the first rotational speed, with the electronics depowered.

Abstract: A method and system for transmitting a facsimile message uses a public-switched telecommunications network, the public-switched telecommunication network having a messaging platform capable of storing a plurality of facsimile messages. The initiation of a telephone call to a destination is detected, the content of the call including the facsimile message. If the destination is available at a first time to receive a telephone call, the facsimile message is transmitted. The facsimile message may be stored on the messaging platform only if the destination is unavailable at the first time, or every time a telephone call is initiated by the originating party. The method also provides for situations where a telephone call is redirected, where an inter-NPA seven digit dialing case has occurred, and where "busy" or "no.sub.-- answer" triggers are implemented. If the facsimile message was stored, the facsimile message is transmitted at a second time if the destination is available.

Abstract: Virtual tracks are set so that the rotation center of a magnetic recording medium or the vicinity of the rotation center coincides with the track center of the data information, and positioning servo control is performed. Thus, since it is not necessary to faithfully follow the track center line specified by the servo information that is previously recorded on the magnetic recording medium or magnetooptical recording medium, a vibration is not easily caused in synchronism with the rotation. Therefore, when the rotation center and the pattern center are deviated from each other, since a vibration is not caused in synchronism with the rotation, the magnetic head of the magnetic recorder or the magnetooptical head of the magnetooptical recorder is able to follow tracks with higher precision. Accordingly, the recording density can be increased.

Abstract: In a base station of a wireless telecommunications system for communicating with mobile terminals, a radiowave is received on a transmission channel and compared in field intensity with a threshold value. The threshold value is considered to be received while unused, in view of the receiver characteristics of the base station, and the base station selects a channel with the field intensity below the threshold value as an idle channel to form an idle channel list. To communicate with a mobile terminal, a channel is selected at random among the channels listed in the idle channel list. This makes it possible to reduce the probability that the same channel as that of a contiguous base station, will be selected and enables the channel selection to be achieved quickly and positively in the base station of the wireless telecommunications system sharing transmission channels of the same frequency band as that of contiguous base stations.