Abstract: Embodiments of the invention provide a magnetic disk drive and magnetic disk drive control method for unloading a head safely with a simple configuration when a positioning control signal cannot be detected due, for instance, to a seek error. In one embodiment, when a head cannot detect servo information prerecorded on a disk, a positioning control section resets and starts a time counting section, and switches to an unloading control section for causing the unloading control section to output a position control signal to a VCM driver. The time counting section counts tacho-pulses generated by a motor driver, and outputs time information. The unloading control section receives the time information from the time counting section. In accordance with the received time information, the unloading control section computes the position control signal that the positioning control section outputs to the VCM driver.

Abstract: Embodiments of the invention provide a magnetic disk drive and magnetic disk drive control method for unloading a head safely with a simple configuration when a positioning control signal cannot be detected due, for instance, to a seek error. In one embodiment, when a head cannot detect servo information prerecorded on a disk, a positioning control section resets and starts a time counting section, and switches to an unloading control section for causing the unloading control section to output a position control signal to a VCM driver. The time counting section counts tacho-pulses generated by a motor driver, and outputs time information. The unloading control section receives the time information from the time counting section. In accordance with the received time information, the unloading control section computes the position control signal that the positioning control section outputs to the VCM driver.

Abstract: A magnetic disk drive has an external environment monitoring function. Data is stored on available disk media while the magnetic disk drive is in an unfavorable environment. Under favorable conditions, the data is then moved to a write-restricted area of the media, which was unavailable while the magnetic disk drive was in the unfavorable environment. The magnetic disk drive uses a temperature sensor/atmospheric pressure sensor as a monitoring device and exercises a function, for example, for reading a reference signal stored in a predetermined area of the medium at predefined intervals. When the external environment is favorable for the magnetic disk drive, the present invention can increase the information storage capacity determined appropriate under the current operating conditions.

Abstract: A magnetic disk drive has an external environment monitoring function. Data is stored on available disk media while the magnetic disk drive is in an unfavorable environment. Under favorable conditions, the data is then moved to a write-restricted area of the media, which was unavailable while the magnetic disk drive was in the unfavorable environment. The magnetic disk drive uses a temperature sensor/atmospheric pressure sensor as a monitoring device and exercises a function, for example, for reading a reference signal stored in a predetermined area of the medium at predefined intervals. When the external environment is favorable for the magnetic disk drive, the present invention can increase the information storage capacity determined appropriate under the current operating conditions.