Abstract: In a system executing a program, a method comprises detecting one or more input/output calls associated with the program and re-randomizing memory associated with the program in response to the one or more input/output calls. A related system is also described.

Abstract: In a system executing a program, a method comprises detecting one or more input/output calls associated with the program and re-randomizing memory associated with the program in response to the one or more input/output calls. A related system is also described.

Abstract: An archival cartridge management system for conditioning removable data cartridges and normal archival operations is disclosed. The archival cartridge management system includes a cartridge holder and a controller. The cartridge holder has a connector configured for coupling to a removable data cartridge. The connector is coupled to the controller, which performs archival functions on removable data cartridges. The controller reads from removable data cartridges to determine if at least some data stored on a removable data cartridge should be refreshed. If so, the controller refreshes data stored on the removable data cartridge.

Abstract: Methods and systems for laser etching of optical servo patterns on magnetic data storage media using two or more beams of laser energy produced from a single source of laser energy to produce a servo pattern on the magnetic data storage media. By using two or more etching beams, the time required to produce a servo pattern on the magnetic data storage media can be significantly reduced. Alternatively, each servo track in the servo pattern can be written more than once. The servo patterns thus formed can be read optically or they may be read magnetically using magnetic overwriting (if the servo pattern is formed in a magnetic coating on the media). In either case, the servo patterns are either permanently formed in the media when read optically, or they can be recreated after bulk erasing if they are provided using magnetic overwriting. In yet another alternative, the servo patterns may be read both magnetically and optically, with the magnetic and optical reading occurring simultaneously or sequentially.

Abstract: A method and apparatus for purging data from a middle cache level without purging the corresponding data from a lower cache level (i.e., a cache level closer to the processor using the data), and replacing the purged first data with other data of a different memory address than the purged first data, while leaving the data of the first cache line in the lower cache level. In some embodiments, in order to allow such mid-level purging, the first cache line must be in the “shared state” that allows reading of the data, but does not permit modifications to the data (i.e., modifications that would have to be written back to memory). If it is desired to modify the data, a directory facility will issue a purge to all caches of the shared-state data for that cache line, and then the processor that wants to modify the data will request an exclusive-state copy to be fetched to its lower-level cache and to all intervening levels of cache.

Abstract: Methods and systems for laser etching of optical servo patterns on magnetic data storage media using two or more beams of laser energy produced from a single source of laser energy to produce a servo pattern on the magnetic data storage media. By using two or more etching beams, the time required to produce a servo pattern on the magnetic data storage media can be significantly reduced. Alternatively, each servo track in the servo pattern can be written more than once. The servo patterns thus formed can be read optically or they may be read magnetically using magnetic overwriting (if the servo pattern is formed in a magnetic coating on the media). In either case, the servo patterns are either permanently formed in the media when read optically, or they can be recreated after bulk erasing if they are provided using magnetic overwriting. In yet another alternative, the servo patterns may be read both magnetically and optically, with the magnetic and optical reading occurring simultaneously or sequentially.

Abstract: Methods and systems for laser etching of optical servo patterns on magnetic data storage media using two or more beams of laser energy produced from a single source of laser energy to produce a servo pattern on the magnetic data storage media. By using two or more etching beams, the time required to produce a servo pattern on the magnetic data storage media can be significantly reduced. Alternatively, each servo track in the servo pattern can be written more than once. The servo patterns thus formed can be read optically or they may be read magnetically using magnetic overwriting (if the servo pattern is formed in a magnetic coating on the media). In either case, the servo patterns are either permanently formed in the media when read optically, or they can be recreated after bulk erasing if they are provided using magnetic overwriting. In yet another alternative, the servo patterns may be read both magnetically and optically, with the magnetic and optical reading occurring simultaneously or sequentially.

Abstract: The present invention provides methods and apparatus for stabilizing data storage media during laser servowriting of optical servo tracks on the media. The apparatus includes a spindle for rotating the media during servowriting, a fixed media platform, and a media support for stabilizing the vertical position of the media during servowriting. The media support may include channels to reduce or control the formation of an air bearing in the area of servowriting to stabilize the vertical positioning of the media. The media support may also include a vacuum slot for drawing a vacuum through the channels.

Abstract: Recording medium disk-hub combination wherein the hub has a central hole whose periphery is bounded at least partly by three flexure members which circumscribe a cylinder corresponding to a disk drive spindle. The three flexure members are arranged in a triangular configuration, and the parts of such flexure members that circumscribe the cylinder are coplanar, forming a flexure member plane of contact. The axial center line of the recording medium disk is spaced from the flexure member plane of contact by no more than three times the thickness of the disk itself. The combination is preferably designed with the ratio of the coefficient of thermal expansion of the hub to that of the recording medium disk being between 0.7 and 1.4. Hub is made magnetic, e.g., by attaching a magnetizable disk. The combination is especially useful for removable recording disks intended to cooperate with disk drives having circular motor spindles and magnetic hold down.

Abstract: For use with a stretched surface recording disk, a recording head having a spherical surface and a series of parallel grooves adjacent the disk and a support arm assembly which maintains the recording head in proper attitudinal relationship to the disk.