Friday, April 13, 2012

What is CHS addressing?

CHS divides the disk into heads, cylinder and sector.
△ Heads: There are two heads in the two sides of the disk, and a head is corresponding to one side of disk. Therefore, the number oh head indicates which side is data located.
△ Cylinder: All concentric tracks with same radius in platters constitute cylinder. It means that the series of tracks pile up vertically and form a cylindrical shape. And number of cylinders = number of tracks.
△ Sector: A track is divided into several small segments called sector. Although small, it is fan-shaped and that is why it is called sector. The capacity of every sector is 512bytes.

If the numbers of heads, cylinders and sectors are known, the location of data can be easily confirmed. Also the capacity of disk can easily be confirmed, and the formula is:
Disk capacity + number of heads × number of cylinders × number of sectors ×512bytes

In LARGE addressing, the number of cylinders is divided by integer and number of heads multiplies integer, then the logical C/H/S parameters are obtained to address. Therefore, it stands for the logical location instead of physical location in disk. LBA addresses in unit of sector instead of C/H/S. In order to be compatible with CHS, LBA can be expressed by C/H/S parameters through logical conversion algorithm. The same as LARGE, it stands for logical location instead of physical location. No matter which disk mode (CHS or LBA) is set in BIOS, MiniTool Partition Wizard can accurately recognize and estimate types and parameters information of the current disk. And it also supports partition management in CHS disk mode.

For more information:

No comments:

Post a Comment