Abstract: An apparatus includes a storage medium, an arm for positioning a recording head adjacent to the storage medium, and a controller for receiving objects and for selecting blocks on the storage medium to be written by the recording head based on information in the objects. A method for storing objects is also provided. In another aspect, the invention provides a method for writing data in data storage devices. The method includes: receiving access commands for objects, selecting blocks on a storage medium to be written by a recording head based on information in the objects, and writing data from the objects to the selected blocks.

Abstract: An arbitration and data source selection mechanism arbitrating access to a shared communication port between a servo engine and a controller of a disc drive is disclosed. In a preferred embodiment, the arbitration and data source selection mechanism, the shared communication port, the servo engine and the controller collectively share a common die of an application specific integrate circuit (ASIC). Servo control code and control code are each loaded into the ASIC for operation of the disc drive. The servo engine is allowed to hold service of the shared serial port dedicated to the servo control code for any length of time required by the servo engine. During periods of non-use by the servo control code, the servo engine releases the shared serial port to the controller for dedicated use by the control code, for a predetermined period of time.

Abstract: A method for improving the operational performance of a disc drive through the identification of vital product information associated with a head-disc assembly (HDA) of the disc drive. The disc drive comprises a printed wiring assembly (PWA) housing control circuitry for the disc drive. The HDA of the disc drive is operably coupled to the printed wiring assembly and includes a rotatable disc to which data are written by a controllably positionable head. A non-volatile memory device is mounted on the HDA and operably coupled to the PWA so that, when the disc drive is initialized, the PWA verifies the configuration of the HDA before proceeding with the initialization of the disc drive, thereby preventing errors and damage to the disc drive as a result of the installation of a new, replacement PWA in the disc drive, or the downloading of new, incorrect firmware to the PWA.

Abstract: An arbitration and data source selection mechanism arbitrating access to a shared communication port between a servo engine and a controller of a disc drive is disclosed. In a preferred embodiment, the arbitration and data source selection mechanism, the shared communication port, the servo engine and the controller collectively share a common die of an application specific integrate circuit (ASIC). Servo control code and control code are each loaded into the ASIC for operation of the disc drive. The servo engine is allowed to hold service of the shared serial port dedicated to the servo control code for any length of time required by the servo engine. During periods of non-use by the servo control code, the servo engine releases the shared serial port to the controller for dedicated use by the control code, for a predetermined period of time.

Abstract: A sliding window type compression scheme is combined with a statistical type compression scheme to provide a dual-mode compression scheme that is optimized for use in compressing operating code in a data storage device. In a sliding window portion of the compression scheme, root and copy items are created, wherein the copy items include a length value and an offset value. The length values and most significant portions of the offset values are then compressed separately in the statistical portion of the compression scheme to form a compressed output which, when combined with the root items form a dually-compressed compressed output. A complimentary decompression scheme is then used to decompress the dually-compressed output.

Abstract: A sliding window type compression scheme is combined with a statistical type compression scheme to provide a dual-mode compression scheme that is optimized for use in compressing operating code in a data storage device. In a sliding window portion of the compression scheme, root and copy items are created, wherein the copy items include a length value and an offset value. The length values and most significant portions of the offset values are then compressed separately in the statistical portion of the compression scheme to form a compressed output which, when combined with the root items form a dually-compressed compressed output. A complimentary decompression scheme is then used to decompress the dually-compressed output.

Abstract: An apparatus for improving the operational performance of a disc drive through the identification of vital product information associated with a head-disc assembly (HDA) of the disc drive. The disc drive comprises a printed wiring assembly (PWA) housing control circuitry for the disc drive. The HDA of the disc drive is operably coupled to the printed wiring assembly and includes a rotatable disc to which data are written by a controllably positionable head. A non-volatile memory device is mounted on the HDA and operably coupled to the PWA so that, when the disc drive is initialized, the PWA verifies the configuration of the HDA before proceeding with the initialization of the disc drive, thereby preventing errors and damage to the disc drive as a result of the installation of a new, replacement PWA in the disc drive, or the downloading of new, incorrect firmware to the PWA.