As information recording media for recording a great amount of information used in computers or other machines, hard disk drive units (hereinafter referred to as HDD devices) have been implemented. The HDD device is provided with a number of magnetic recording disks (referred to as disks) and writes information in or reads it from a disk by positioning a read/write head onto a desired track defined on the disk.
Typically the disk in the HDD device is provided with a plurality of tracks, each of which is divided into data sectors (referred to as sectors) which are 128, 256, or 512 bytes. A divided sector is usually given an identifier of itself, i.e., a so-called sector ID, having a serial number of the sector, sector type, and sector identifying information such as DEFECT information indicating a bad sector originated from manufacturing. In a conventional HDD device, read and write operations are performed while the sector ID is referenced to determine whether the sector is the target or not.
The physical location of the sector can be determined from the face number of the disk (HEAD number), the cylinder number (CYL number), and the sector number (SCT number). The HEAD number and CYL number can be determined as a seek operation ends. The SCT number can be determined by reading information previously recorded on the disk, such as the servo area, or by counting from the beginning sector, since the SCT number changes with the rotation of the disk.
It is necessary for reading or writing information to perform operations for every sector, such as convening a logical sector into a physical sector and identifying a location on the disk where a corresponding sector belongs. This requires many types of information to be stored in the sector ID. Therefore the ID region has been made larger so as to prevent erroneous sector identifying information from being recorded as prerequisite sector identifying information is too large to be recorded. Then, an area for controlling the HDD device for each sector, i.e., an ID area of sector identifying information, has been affixed, thus necessitating reduction of the area where information can be recorded and which is originally provided in the HDD device by using the ID area.
To overcome this problem, there has been suggested an information recording disk whose sectors are so formatted that the ID area is not required for recording information (see JA5-174498).