Abstract: Hard biasing of a magnetoresistive sensor or a spin valve sensor in a magnetic read head is initialized by repeatedly applying a magnetic field to the hard biasing at any level of fabrication of the magnetic read head or any combination of levels of fabrication of the read head such as at the wafer level, row bar level, single slider level, head gimbal assembly (HGA) level and/or head stack assembly (HSA) level.

Abstract: The present invention provides a reaction vessel and apparatus for performing heat-exchanging reactions. The vessel has a chamber for holding a sample, the chamber being defined by a plurality of walls, at least two of the walls being light transmissive to provide optical windows to the chamber. The apparatus comprises at least one heating surface for contacting at least one of the plurality of walls, a heat source for heating the surface, and optics positioned to optically interrogate the chamber while the heating surface is in contact with at least one of the plurality of walls. The optics include at least one light source for transmitting light to the chamber through a first one of the light transmissive walls and at least one detector for detecting light exiting the chamber through a second one of the light transmissive walls.

Abstract: A data recovery method for a read assembly of a magnetic memory device. The magnetic memory device has a moving magnetic medium, such as a disk, and a transducer spaced from the disk by a normal gap distance. The read assembly includes a variable gain amplifier and a control computer that controls the read and write operations of the magnetic memory device. The data recovery method uses the control computer to adjust the gain of the amplifier when an error is detected in a read signal. The method tests to see if the error is due to a variance from the normal gap distance by the head that is caused by either an thermal asperity of the disk surface or by a change in temperature of the moving magnetic medium. If a variance is found, the amplifier gain is adjusted and the data is reread. If there is no error the data is provided to an output interface.

Abstract: A method and apparatus for compensating for multiple thermal asperity events in a sector. The present invention provides for the detection, recording and recovery from errors caused by multiple thermal asperities occurring in a single sector. The method includes detecting thermal asperity events in a sector, setting a flag indicating each occurrence of a thermal asperity event in the sector, maintaining a count of the detected thermal asperity events in the sector and recording a byte location for each of the detected thermal asperity events in the sector. The method further includes performing a data recovery procedure in response to the detected thermal asperity events. The data recovery procedure is performed using the flag settings and a location corresponding to the detected thermal asperity events. The data recovery procedure is performed using the count of the detected thermal asperity events. The setting of a flag includes setting a bit in a register.

Abstract: A method in a data processing system for minimizing read/write errors caused by impaired performance of a hard disk drive during runtime operation of the hard disk drive. The runtime operation includes an active mode during which read/write operations are conducted and a standby mode which occurs while no read/write operation is underway. First, at least one performance parameter of a hard disk drive is monitored during a standby mode of operation. Next, in response to detecting a degraded value of the at least one performance parameter, performing preventive recovery action only during the standby mode of operation, such that the performance parameter is restored to an acceptable value without interfering with hard disk drive operation during an active mode.

Abstract: A system to control the interior temperature and particularly the slider and disk temperature of hard disk drives that utilizes the spindle motor to spin a fanning structure. The fanning structure is preferably integrated into the hard disk drive and initiates a cooling air stream that is directed within the contained interior of the hard disk drive toward a Peltier-element that drains the thermal energy into the surrounding environment. In an alternate embodiment, the fanning structure initiates an exterior air stream that provides a cooling air stream at the outside of the Peltier-element. The Peltier-element is controllable to decouple operational temperature variations from environmental temperature variations.

Abstract: A method and apparatus for providing amplitude instability data recovery for AMR/GMR heads during amplitude loss using MSE and/or amplitude envelope detection procedures. The method includes (a) initiating a data recovery procedure by selecting a detection mode for detecting when an error condition occurs, (b) performing the selected detection mode, (c) determining a reset action for resetting the magnetic head, (d) performing the reset action to reset the magnetic head and (f) re-reading data in the track after performing the reset action. An embodiment of the invention further includes (g) determining whether the resetting of the magnetic head allowed recovery of the data in the track and (h) terminating the data recovery procedure when the data is recovered.

Abstract: A method and system for detecting common mode disturbances from a magnetic recording head having dual magnetic recording elements. An electrical current is supplied to both of the dual magnetic recording elements within the magnetic recording head. Thereafter, the electrical current is shunted through only one of the dual magnetic recording elements. A voltage signal is then detected across the dual magnetic recording elements, which occurs in response to the shunting of the electrical current through only one of the dual magnetic recording elements. Finally, the voltage signal is analyzed for indications of common mode disturbances accentuated as a result of the shunting of the electrical current through only one of the dual magnetic recording elements. Common mode disturbances that can be detected include thermal asperities.

Abstract: A modular enclosure for personal computer systems substantially comprises a 5-sided steel chassis, a plastic subassembly tray, a plastic detachable back panel, and a 4-sided plastic top cover including an integrally formed front panel. The internal subassembly tray comprises appropriately formed bays designed to receive various system subassemblies, each bay having an integrally formed subassembly retaining means to bear against and retain a subassembly placed in the bay. Top side and rear electromagnetic interference (EMI) shields are fitted and secured to the interior portions of the plastic topcover and rear panel so as to peripherally contact the chassis when the topcover and rear panel are installed. The internal subassembly tray is lowered into the interior region of the chassis and snapped into place at the front portion thereof. The rear panel is then positioned and secured to the chassis.