Patent ID: 7404034

Claim:
A disk drive device comprising: a head for executing data write on a disk medium and data read from the disk medium; a register which is configured to be accessible by a host device and stores various commands which are transmitted from the host device; a read/write process unit which executes a read/write control process including a write operation of controlling the head in accordance with a write command that is written in the register by the host device and writing write data, which is transmitted from the host device, on the disk medium, or a read operation of controlling the head in accordance with a read command that is written in the register by the host device and reading out data from the disk medium; a cache memory which stores the write data that is transmitted from the host device and the read data that is read out of the disk medium; and a control unit which executes an unload operation of retreating the head to a predetermined retreat position that is located outside the disk medium in a case where an unload command is written in the register by the host device during execution of the read/write control process, and controls data transfer between the cache memory and the host device in accordance with the read command or the write command, thereby to continuously execute the read/write control process.