Abstract: The invention relates to an adhesive tape for a flying roll change, including: a carrier material (1) with an upper side, an underside and two longitudinal edges (1a, 1b), wherein the upper side of the carrier material (1) is coated with an adhesive (4) and the underside of the carrier material (1) is formed non-adhesive; and a double-sided adhesive tape (2) with an upper side, an underside and two longitudinal edges (2a, 2b), which includes a cleavable carrier material (21) which on both sides is coated with an adhesive (22, 23). The double-sided adhesive tape (2) is arranged on the underside of the carrier material (1). It is provided that the double-sided adhesive tape (2) is arranged on the underside of the carrier material (1) such that a partial region (B) of the double-sided adhesive tape (2) protrudes from the one longitudinal edge (1a) of the carrier material (1). The invention furthermore relates to the use of such adhesive tape for a flying roll change.

Abstract: The invention relates to an adhesive tape for a flying roll change, including: a carrier material (1) with an upper side, an underside and two longitudinal edges (1a, 1b), wherein the upper side of the carrier material (1) is coated with an adhesive (4) and the underside of the carrier material (1) is formed non-adhesive; and a double-sided adhesive tape (2) with an upper side, an underside and two longitudinal edges (2a, 2b), which includes a cleavable carrier material (21) which on both sides is coated with an adhesive (22, 23). The double-sided adhesive tape (2) is arranged on the underside of the carrier material (1). It is provided that the double-sided adhesive tape (2) is arranged on the underside of the carrier material (1) such that a partial region (B) of the double-sided adhesive tape (2) protrudes from the one longitudinal edge (1a) of the carrier material (1). The invention furthermore relates to the use of such adhesive tape for a flying roll change.

Abstract: A filter representing a complex impedance of a motor system based on a deviation between a first voltage driven by a command signal and a second voltage driven by the command signal can be dynamically adjusted. The motor system can be held in a steady state, eliminating back electromotive force, by providing zero mean current excitation.

Abstract: An electronic device includes a flag circuit configured to generate a status flag indicating whether or not a power supply voltage to the electronic device has been cycled, and a controller configured to control an operation of the electronic device and to modify an operational characteristic of the electronic device in response to the status flag indicating that the power supply voltage to the electronic device has been cycled. Methods of operating an electronic device include generating a status flag indicating whether or not a power supply voltage to the electronic device has been cycled within about a defined time, and modifying an operational characteristic of the electronic device in response to the status flag indicating that the power supply voltage to the electronic device has been cycled within about the defined time.

Abstract: A filter representing a complex impedance of a motor system based on a deviation between a first voltage driven by a command signal and a second voltage driven by the command signal can be dynamically adjusted. The motor system can be held in a steady state, eliminating back electromotive force, by providing zero mean current excitation.

Abstract: A fly height controller measures electrical resistance of a heater element attached to a read/write head as an indication of head temperature and associated flying height relative to a data storage disk, and responds to the measured resistance of the heater element by varying a fly height adjustment signal applied to the heater element to change the temperature of the head and its resulting flying height.

Abstract: A disk drive includes a rotatable data storage disk, a transducer, an actuator, and a servo burst demodulator. The rotatable data storage disk includes a plurality of servo burst patterns thereon. The plurality of servo burst patterns are substantially radially aligned to each other, and radially adjacent ones of the servo burst patterns are configured to generate contributions to a read signal that are substantially orthogonal to each other. The transducer is configured to read the servo burst patterns on the disk to generate the read signal. The actuator is configured to position the transducer relative to the disk. The servo burst demodulator is configured to identify a separate contribution to the read signal from the radially adjacent servo burst patterns. The servo burst demodulator may be configured to generate transducer position information based on the identified separate contribution to the read signal from the radially adjacent servo burst patterns.

Abstract: A fly height controller measures electrical resistance of a heater element attached to a read/write head as an indication of head temperature and associated flying height relative to a data storage disk, and responds to the measured resistance of the heater element by varying a fly height adjustment signal applied to the heater element to change the temperature of the head and its resulting flying height.

Abstract: An electronic device includes a flag circuit configured to generate a status flag indicating whether or not a power supply voltage to the electronic device has been cycled, and a controller configured to control an operation of the electronic device and to modify an operational characteristic of the electronic device in response to the status flag indicating that the power supply voltage to the electronic device has been cycled. Methods of operating an electronic device include generating a status flag indicating whether or not a power supply voltage to the electronic device has been cycled within about a defined time, and modifying an operational characteristic of the electronic device in response to the status flag indicating that the power supply voltage to the electronic device has been cycled within about the defined time.

Abstract: A disk drive includes a rotatable data storage disk, a transducer, an actuator, and a servo burst demodulator. The disk includes a servo burst pattern thereon within a single servo sector. The transducer is configured to generate a read signal from the servo burst pattern. The actuator is configured to position the transducer relative to the disk. The servo burst demodulator is configured to generate a position error signal from the contributions of the servo burst pattern to the read signal, and is configured to generate a fly height signal from the contributions of the servo burst pattern to the read signal. The position error signal is indicative of a radial location of the transducer relative to the disk. The fly height signal is indicative of a height of the transducer from the disk.

Abstract: An apparatus and method for increasing the data storage capacity of a data storage device 100 having media surfaces 23. One or more of a linear density of data, a track density of data, or an error code level of data, is selected for a portion 35 of a media surface 23. Data is recorded on the portion 35 of the media surface 23 at the selected linear density, track density, or error code level. Thereafter, the recorded data is read and an error rate of the recorded data is derived, directly or indirectly. The derived error rate is compared to an acceptable error rate, and if the derived error rate is greater than the acceptable error rate, the previous steps are repeated for another linear density, track density, or error code level, until the derived error rate is less than or equal to the acceptable error rate, to provide a recordable linear density, track density, or error code level of data for the media surface 23.

Abstract: A parity check matrix is generated for detecting predefined errors in a coded string of bits. A column of the matrix is generated by selecting values for elements in the column and processing a predefined error with the selected values in order to produce a syndrome. The selected values are assigned to the column of the parity check matrix if an element of the syndrome has a value indicative of the predefined error.

Abstract: A network storage device having a network controller card and a data storage device is described herein the card and storage device are either enclosed in a small from factor unit or assembled together to fit within a standard hard disk drive bay in a computer. The combination of a controller card and storage device is designed to transfer files from and to a network using standard network file protocols. As the network storage device does not process the files, much of the computational overhead of a network server can be eliminated, resulting in a simpler device capable of faster file exchange.

Abstract: Several ways of avoiding collisions between a transducer and asperities on the surface of a moving data storage medium are described. In general, information that indicates locations of the asperities on the surface is provided, and relative movement between the transducer and the surface is altered in response to the information. Approaches for altering the relative movement include preventing the transducer from idling over a track that contains an asperity or over a nearby track, and moving the transducer over an asperity-containing track before a read/write operation or away from the track after the read/write operation to avoid colliding with the asperity. In another technique, the transducer is temporarily moved away from the track as the asperity approaches during a data exchange, and is then returned to the track after the asperity passes.

Abstract: A Reed-Solomon error-correction coding (ECC) scheme selectively supports two different-length codes to optimize the trade-off between error performance and the amount of disk space required to store protection symbols. The encoder contains two sets of alpha multipliers; part of one set is multiplexed with the other depending on which code is being used. Also, a shift register within the encoder is selectively lengthened or shortened depending on the code. The code pair is selected so that the generator polynomial of the shorter code is a complete divisor of the generator polynomial of the longer code. Thus, one code is a sub-code of the other. Accordingly, the ECC system is able to use the same syndrome calculator for each code. The error-correction decoder uses those syndromes that correspond to the roots of the generator polynomial of the code being used.

Abstract: An encoding system uses a modified 8/9 rate modulation code to encode 8-bit data symbols into 9-bit cells in a conventional manner in accordance with the modified code and 9-bit ECC symbols into 10-bit cells by (i) encoding 8 bits of the symbol into a 9-bit cell in accordance with the modified code, and (ii) inserting into the 9-bit cell the remaining, that is, the non-encoded, bit of the ECC symbol. The system reproduces the 8-bit data symbols by decoding the 9-bit cells in a conventional manner in accordance with the modified code, and the 9-bit ECC symbols by (i) removing from the associated 10-bit cell the bit inserted during encoding, (ii) decoding the remaining 9 bits to reproduce 8 bits of the symbol, and (iii) inserting into the 8 bits the bit that was earlier removed. In an exemplary embodiment, the 8 least significant bits of the ECC symbol are encoded using the modified 8/9 rate code. The 9 bits produced by the code are used essentially as the first "c" bits and last "10-c" bits of a 10-bit cell.

Abstract: A phase locked loop that operates on an input signal received from a disk drive and similar data processing system peripherals, where the input signal has a preamble portion and a data portion. The phase locked loop providing a digital clock signal which is phase locked to the preamble portion. This is accomplished by adjusting the loop response time so that it monotonically decreases in amplitude beginning at a time when the phase locked loop receives the preamble portion and continuing to monotonically decrease during at least a portion of the time that the phase locked loop receives the data portion. The response time may be monotonically decreased in any suitable fashion, such as linearly or exponentially. A specific embodiment of a linearly decreasing signal generator used with a charge pump is disclosed. The results of computer simulations showing a decrease in lock acquisition time and increased noise immunity with shortened preamble time are also discussed.

Abstract: A data decoding circuit which receives an input signal comprising a sequence of pulses and generates a digital data output signal and timing signals in response thereto. The circuit includes a phase-locked loop which generates timing signals in response to the input signal and an offset signal from a data separator circuit. The data separator circuit generates the digital data output signal and the offset signal, which measures the degree of correlation between the input signal as received by the data separator and the timing signal from the phase-locked loop, thereby obviating the need to match the data separator circuit closely to the phase-locked loop.

Abstract: An AGC system for controlling the gain of an amplifier includes an AGC multiplexer and an AGC circuit. The AGC circuit receives an input signal from the AGC multiplexer and generates, in response thereto a gain control signal. The AGC multiplexer operates in three modes. In a first mode, in which the erased portion of a sector is being detected, the AGC multiplexer couples an input preset signal of a predetermined voltage level to the AGC circuit, enabling it, in turn, to generate a gain control signal to control the gain to a predetermined level. In a second mode, the AGC multiplexer couples a signal related to the output signal from the amplifier to the AGC circuit, enabling the AGC circuit to generate a gain signal related to the output level of the amplifier. In the third mode, the AGC multiplexer maintains its output signal constant, thus enabling the AGC circuit to maintain its gain control constant.

Abstract: In a video terminal system wherein a number of characters are to be displayed on each forward horizontal scan, a scan control circuit is utilized to synchronize the displaying of characters with the scanning of the cathode ray tube. Both the scan control circuit and the displaying characters are tied to a timing chain. Since the displaying of characters occurs at a fixed predetermined time in the timing chain, the scan control circuit is required to control the movement of the scan such that the phase of the scan is regulated in time. The scan control circuit accomplishes synchronization by a self-regulating feedback circuit which controls the magnitude of the base drive to a power transistor. Since the storage time of a power transistor is proportional to the magnitude of the base drive current to the power transistor, a simplified circuit results which accurately places the characters at a fixed position.