Abstract: An apparatus and method for selecting physical cylinders (cylinders accessible for read/write operations) in a disc drive is provided. The disc drive includes at least one rotatable disc. The disc drive also includes a first head, which is positionable adjacent a first disc surface, and a second head, which is positionable adjacent a second disc surface. The first disc surface has a first plurality of greycode tracks and the second disc surface has a second plurality of greycode tracks. Each greycode track of the second plurality of greycode tracks corresponds to a different greycode track of the first plurality of greycode tracks, thereby forming a plurality of greycode cylinders, with each greycode cylinder of the plurality of greycode cylinders including a pair of corresponding greycode tracks. The physical cylinders are a subset (less than all) of the plurality of the greycode cylinders.

Abstract: A device such as a chain tensioner arm and the method of forming the same are provided. The device includes a top wearing member and a bottom structural member, in which the device is produced by forming the top wearing member and the bottom structural member in a single molding cycle.

Abstract: By dynamically adjusting the maximum voice coil motor driving current produced by an amplifier in a disc drive, amplifier saturation may be reduced, while still maintaining optimal current to quickly drive the voice coil motor during seek operations. Reducing disc drive saturation, and thus non-linearities in the driving current, increases notch filter performance. As the notch filter is used in the disc drive to remove frequencies from the driving current that tend to cause or excite the mechanical oscillations in the disc drive, increased notch filter performance reduces mechanical oscillations and improves disc drive noise characteristics.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: A device such as a chain tensioner arm and the method of forming the same are provided. The device includes a top wearing member and a bottom structural member, in which the device is produced by forming the top wearing member and the bottom structural member in a single molding cycle.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: A Method and Apparatus of IEEE 1394 Tone Transmission in Beta Mode is disclosed. The invention relates to a method for the transmission of clock signal in IEEE 1394 beta mode, known as “tone.” The system comprising a controller for automatic adjustment of the level of power consumption of the device responsive to whether or not an effective bus connection is being made, a current reference having temperature compensation, a self-calibrating oscillator, a “tone” transmitter, a “tone” receiver, and termination circuitry. While in standby mode, and when no cable is interconnecting the device to another device, the device transmits tones and listens for incoming tones while maintaining low power consumption. When a cable is plugged in, the device awakens automatically and resumes normal IEEE 1394 transmissions.

Abstract: A reticle incorporates an optical center and a plurality of measuring points. The measuring points are formed by a primary vertical line, a primary horizontal line intersecting the primary vertical line at the optical center, a plurality of dots intersecting the primary lines and evenly spaced at a predetermined distance along the primary lines, a plurality of secondary lines intersecting one of the primary lines and evenly spaced between the dots therein. The secondary lines are shorter than 0.2 mil. Alternatively, the reticle further incorporates at least one post on at least one end of the primary lines with post hash marks thereon. Each the intersecting lines forms one of the plurality of measuring points.

Abstract: A reticle incorporates an optical center and a plurality of measuring points. The measuring points are formed by a primary vertical line, a primary horizontal line intersecting the primary vertical line at the optical center, a plurality of dots intersecting the primary lines and evenly spaced at a predetermined distance along the primary lines, a plurality of secondary lines intersecting one of the primary lines and evenly spaced between the dots therein. The secondary lines are shorter than 0.2 mil. Alternatively, the reticle further incorporates at least one post on at least one end of the primary lines with post hash marks thereon. Each the intersecting lines forms one of the plurality of measuring points.

Abstract: By dynamically adjusting the maximum voice coil motor driving current produced by an amplifier in a disc drive, amplifier saturation may be reduced, while still maintaining optimal current to quickly drive the voice coil motor during seek operations. Reducing disc drive saturation, and thus non-linearities in the driving current, increases notch filter performance. As the notch filter is used in the disc drive to remove frequencies from the driving current that tend to cause or excite the mechanical oscillations in the disc drive, increased notch filter performance reduces mechanical oscillations and improves disc drive noise characteristics.

Abstract: A disposable disruptor device including a stator and a rotor. The rotor is disposed for rotation in the stator and has blades at one end thereof. A reverse-threaded helical ridge between the stator and the rotor pumps fluid down the stator and prevents fluid from being drawn up inside the stator tube.

Abstract: An angled rotatable cable connector is described. The cable connector has a first end for attaching to a termination point of a cable, and a second end adapted to attach to a fixed panel-mounted mating connector. The first end and second end of the cable connector are supplied as sub-assemblies, mounted within a common outer body, so that, after connection, both the cable attached to the first end, and the connector, attached to the mating connector, remain free to rotate around their respective axes.