Abstract: Write pointer management for a disk drive including a disk having a plurality of sectors and a non-volatile memory (NVM) for storing data. Data is sequentially written sector by sector on the disk. The data written in a sector includes a write status indicator indicating that data has been written in the sector. A write pointer is stored on the disk or the NVM as a check-pointed write pointer. The write pointer corresponds to a current sector for writing data on the disk. During a write pointer recovery process, the check-pointed write pointer is retrieved, and at least one write status indicator is scanned in a range of sectors from the sector corresponding to the retrieved check-pointed write pointer and a last sector to identify the current sector for writing data. The write pointer is set to correspond to the identified current sector.

Abstract: A disk drive is disclosed comprising a disk, a head, and a ramp located near an outer periphery of the disk. The disk drive further comprises control circuitry operable to load the head off the ramp over the disk, receive an unload command to perform an unload operation, evaluate a number of unloads relative to an unload limit that varies over time, and when the number of unloads exceeds the unload limit, delay the unload operation.

Abstract: A data storage device is disclosed comprising a non-volatile memory and control circuitry operable to evaluate a physical feature of the data storage device, wherein the physical feature is physically alterable by a user. When the physical feature is in a first state, host access to first secure data stored in the non-volatile memory is enabled, and when the physical feature is in a second state, the host access to the first secure data is disabled and host access to second data stored in the non-volatile memory is enabled.

Abstract: A disk drive comprising a head actuated over a disk, and control circuitry operable to spin the disk at a first spin rate. The control circuitry is further operable to reduce the spin rate of the disk from the first spin rate to a second spin rate, wherein the second spin rate is based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate. For example, the spin-up parameter may comprise one or more of a spin-up time limit, power setting, and ambient temperature.

Abstract: A data storage device is disclosed comprising a non-volatile memory and control circuitry operable to evaluate a physical feature of the data storage device, wherein the physical feature is physically alterable by a user. When the physical feature is in a first state, host access to first secure data stored in the non-volatile memory is enabled, and when the physical feature is in a second state, the host access to the first secure data is disabled and host access to second data stored in the non-volatile memory is enabled.

Abstract: A method and apparatus are provided for digitally correcting sector pulse placement in a direct access storage device. A sector clock signal is generated equal to a sub-multiple clock rate of a predetermined servo identification clock. An individual servo identification field location is identified and compared with an expected location of said individual servo identification field to identify an error value. The sector clock signal is modified by adding or subtracting clock pulses responsive to the identified error value for generating a sector pulse.

Abstract: A method and apparatus for modulating a data reference clock for rotational speed variations of the data storage disk in a direct access data storage file. A data reference clock is generated from an encoded disk rate clock of the data file. A readback signal from at least one predetermined region of the disk surface is sensed and a sync byte is detected responsive to the readback signal. An early window control signal and a late window control signal are generated corresponding to end boundaries for capturing readback encoded data signals. A load complete signal is identified responsive to the readback signal. The identified load complete signal with the early window control signal and the late window control signal and the generated data reference clock is adjusted responsive to overlapping compared signals.