Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of tracks, each track comprising a plurality of data sectors. A circular buffer is defined comprising a plurality of the tracks. During a garbage collection operation, write data is read from previously written valid data sectors corresponding to a tail of the circular buffer and stored in a non-volatile cache. During a flush operation, the write data is flushed from the non-volatile cache to the disk.

Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, and a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments. When a life remaining of the NVSM falls below a threshold, the NVSM is marked as read only. When a write command is received from a host including write data, and when the NVSM is marked as read only, the write data is written to the disk and a corresponding memory segment in the NVSM is invalidated.

Abstract: A hybrid drive is disclosed comprising a head actuated over a disk, and a non-volatile semiconductor memory (NVSM). When a write command is received from a host that is mapped to the NVSM, the write command is serviced by writing data to the NVSM, and when a life remaining of the NVSM falls below a threshold, by also writing a copy of the data to the disk.

Abstract: A hybrid drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, where each data track comprises a plurality of data sectors. The hybrid drive further comprises a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments. When a write command is received from a host including write data, the write data is written to one of a disk cache and a NVSM cache, wherein the write data is eventually flushed to a non-cache area of the disk.

Abstract: A method of operating a peripheral data storage system(PDSS) for use with a host system configured to perform scheduled backup operations to PDSS comprising a user-actuated backup signaling subsystem(UBSS), a user-notifying device comprising first and second notifying states, and a host interface adapted for communication with the host system. The method comprises receiving a first signal from UBSS; communicating first signal to host system via host interface; receiving an acknowledgement signal from host system in response to communicating; and switching user-notifying device between first notifying state and second notifying state in response to received acknowledgement signal. Another method comprises receiving in host system a first request from PDSS for performing a task corresponding to a host-scheduled backup operation for a scheduled backing up of data to PDSS; completing the task by host system based on received first request; and notifying PDSS of completion of the task by host system.

Abstract: A method of displaying states of a peripheral data storage system (PDSS) comprising a data storage device, a data storage system controller, a user-actuated signaling subsystem, a user display subsystem adapted to display the states, and a peripheral data storage controller host interface adapted for communication with a host system. The method includes determining a state of the PDSS; displaying a first display state via the user display subsystem if the PDSS is in an idle state; displaying a second display state via the user display subsystem if the PDSS is in a state corresponding to receiving a signal from the user-actuated signaling subsystem; displaying a third display state via the user display subsystem if the PDSS is in a dynamically active state; and displaying a fourth display state via the user display subsystem if the PDSS is in an off state.

Abstract: In an external disk drive system comprising a disk drive, a bridge controller comprising a plurality of Bridge Controller Host (BCH) interfaces adapted to establish communication between the external disk drive system and an external device via a plurality of different communication mediums, a method for switching from a first BCH-interface communicating with the external device via a first communication medium to a second BCH-interface during the operation of the external disk drive system. The method comprising sensing a connecting of a second communication medium to the external disk drive system via the second BCH-interface; determining an interface priority of the second communication medium over an interface priority of the first communication medium; dismounting the disk drive from the first communication medium based on the determining; and mounting the disk drive to the second communication medium wherein the external disk drive system remains operational during the dismounting an mounting.

Abstract: An information storage system includes a transducer having a loop of ferromagnetic material with pole tips separated by an nonferromagnetic gap located adjacent to a medium such as a rigid disk. During writing the separation between the pole tips and the media layer of the disk is a small fraction of the gap separation. Due to the small separation between the pole tips and the media layer, the magnetic field generated by the transducer and felt by the media has a larger perpendicular than longitudinal component, favoring perpendicular recording over longitudinal recording. The media may have an easy axis of magnetization oriented substantially along the perpendicular direction, so that perpendicular data storage is energetically favored. The transducer may also include a magnetoresistive sensor for reading magnetic information from the disk.

Abstract: A hard disk drive head operates in close proximity and dynamic contact with a rapidly spinning rigid disk surface, the head including a transducer with a magnetically permeable path between a poletip disposed adjacent to the disk surface and a magnetoresistive (MR) sensor situated outside the range of thermal noise generated by the surface contact. The magnetically permeable path is the same as that used to write data to the disk, eliminating errors that occur in conventional transducers having MR sensors at a separate location from the writing poletips. Moreover, the magnetically permeable path is preferably formed in a low profile, highly efficient “planar” loop that allows for manufacturing tolerances in throat height and wear of the terminal poletips from disk contact without poletip saturation or poletip smearing. The MR layer is formed in one of the first manufacturing steps atop the substrate, so that the MR layer has a relatively uniform planar template that is free from contaminants.

Abstract: A transducer for a hard disk drive system has a planar magnetic core and a pair of poletips that project transversely from the core for sliding contact with the disk during reading and writing. The transducer is formed entirely of thin films in the shape of a low profile table having three legs that slide on the disk, the poletips being exposed at a bottom of one of the legs for high resolution communication with the disk, the throat height of the poletips affording sufficient tolerance to allow for wear. The legs elevate the transducer from the disk sufficiently to minimize lifting by a thin air layer that moves with the spinning disk which, in combination with the small size of the thin film head allows a low load and a flexible beam and gimbal to hold the transducer to the disk.

Abstract: An information storage system includes a transducer having a loop of ferromagnetic material with pole tips separated by an nonferromagnetic gap located adjacent to a medium such as a rigid disk. During writing the separation between the pole tips and the media layer of the disk is a small fraction of the gap separation. Due to the small separation between the pole tips and the media layer, the magnetic field generated by the transducer and felt by the media has a larger perpendicular than longitudinal component, favoring perpendicular recording over longitudinal recording. The media may have an easy axis of magnetization oriented substantially along the perpendicular direction, so that perpendicular data storage is energetically favored. The transducer may also include a magnetoresistive sensor for reading magnetic information from the disk.

Abstract: A hard disk drive head operates in close proximity and dynamic contact with a rapidly spinning rigid disk surface, the head including a transducer with a magnetically permeable path between a poletip disposed adjacent to the disk surface and a magnetoresistive (MR) sensor situated outside the range of thermal noise generated by the surface contact. The magnetically permeable path is the same as that used to write data to the disk, eliminating errors that occur in conventional transducers having MR sensors at a separate location from the writing poletips. Moreover, the magnetically permeable path is preferably formed in a low profile, highly efficient “planar” loop that allows for manufacturing tolerances in throat height and wear of the terminal poletips from disk contact without poletip saturation or poletip smearing. The MR layer is formed in one of the first manufacturing steps atop the substrate, so that the MR layer has a relatively uniform planar template that is free from contaminants.

Abstract: An information storage system having a ring head sliding on a rigid magnetic storage disk in such close proximity that the magnetic field felt by the media layer or layers of the disk has a larger perpendicular than longitudinal component so that data is stored in a perpendicular mode. The head to media separation during writing of data to the media is a small fraction of the amagnetic gap separating the poletips of the head. Reading of data may be inductive or may be via a magnetoresistive sensor which is coupled to the magnetically permeable core of the ring head far from the poletips. The media preferably has a high perpendicular anisotropy.

Abstract: An information storage system having a ring head in such close proximity to a rigid magnetic storage disk that the magnetic field felt by the media layer or layers of the disk has a larger perpendicular than longitudinal component so that data is stored in a perpendicular mode. Reading of data is accomplished with a magnetoresistive sensor which may be coupled to the magnetically permeable core of the ring head far from the poletips, which may contact the disk. The media preferably has a high perpendicular anisotropy, and may be formed in a plurality of films with crystalline structures traversing the films.

Abstract: A hard disk drive head operates in close proximity and dynamic contact with a rapidly spinning rigid disk surface, the head including a transducer with a magnetically permeable path between a poletip disposed adjacent to the disk surface and a magnetoresistive (MR) sensor situated outside the range of thermal noise generated by the surface contact. The magnetically permeable path is the same as that used to write data to the disk, eliminating errors that occur in conventional transducers having MR sensors at a separate location from the writing poletips. Moreover, the magnetically permeable path is preferably formed in a low profile, highly efficient “planar” loop that allows for manufacturing tolerances in throat height and wear of the terminal poletips from disk contact without poletip saturation or poletip smearing. The MR layer is formed in one of the first manufacturing steps atop the substrate, so that the MR layer has a relatively uniform planar template that is free from contaminants.

Abstract: A planar thin film magnetic head comprises an insulating substrate, a pair of insulating pedestals formed on the substrate, a top magnetic yoke having a central portion disposed over the substrate and having opposite ends supported on each of the pedestals. A conductor is provided over the top yoke central portion, and an insulating layer is disposed between the conductor and the top magnetic yoke. A bottom magnetic yoke is disposed over the conductor and has a gap in a central portion and opposite ends in contact with the top yoke ends.

Abstract: Boundary protrusions or kinks are integrally formed along the perimeter of a magnetic layer of a magnetic transducer for nucleating a predetermined domain pattern in the magnetic layer. These protrusions or kinks behave as domineering pinning sites for the domain walls, overriding other factors such as manufacturing tolerances or external magnetic field, for establishing a stable magnetic domain pattern. As arranged, various kinds of noise encountered during the normal operations of the transducer are significantly reduced, as the noise related problems originated from the magnetic domain instabilities in the magnetic layers are substantially curtailed.

Abstract: A magnetoresistive (MR) sensing system comprises an MR sensor with a layered spin valve structure including thin first and second layers of ferromagnetic material separated by a thin layer of nonmagnetic metallic material. The magnetization direction of the first layer at a zero applied magnetic field is substantially parallel to the longitudinal dimension of the MR sensor and substantially perpendicular to the fixed or "pinned" magnetization direction of the second layer. A thin keeper layer of ferromagnetic material is separated by a thin spacer layer from the layered spin valve structure. This keeper layer has a fixed magnetization direction substantially opposite that of the second layer and a moment-thickness product substantially equal to that of the second layer for cancelling the magnetostatic field from the second layer.

Abstract: The present invention is a yoke spin valve MR read head which electrically connects a spin valve MR sensor to spaced apart yoke portions. First and second yoke pieces are electrically connected at a head surface and are insulated from one another at a back gap which is remotely located from the head surface. The first yoke piece has a break which divides it into first and second portions which are spaced from one another. The spin valve MR sensor is located within this break and electrically interconnects the first and second portions of the first yoke piece. First and second leads are connected to the first and second yoke pieces respectively and receive a current from a current source for applying a sense current to the spin valve MR sensor via the first and second yoke pieces. When a magnetic medium is moved adjacent the head surface of the read head the yoke pieces serve as conductors for transmitting sense current to the spin valve MR sensor as well as functioning as a flux guide.

Abstract: A magnetoresistive read transducer includes a magnetoresistive (MR) layer having end regions spaced by a central active regions. A pair of hard-magnetic layers provide the longitudinal magnetic bias to the magnetoresistive layer. Each of the hard-magnetic layers is disposed in contact with one of the end regions of the magnetoresistive layer. In addition, a pair of electrical leads provide the bias current to the magnetoresistive layer. Each of the electrical leads is also disposed in contact with one of the end regions of the magnetoresistive layer. This arrangement enable the transducer of the present invention with the most optimal design. In essence, electrical current directly passes through the central active region of the magnetoresistive layer via the electrical leads as a low electrical resistance path. Magnetic flux of the longitudinal bias directly passes through the central active region of the magnetoresistive layer with a reduced probability of magnetic discontinuity.