HOW IS DATA STORED IN HARD DISK

 HOW IS DATA STORED IN HARD DISC

Hard disc, also called hard drive or hard disk drive, magnetic storage medium for a computer. Hard disc are flat circular plates made of aluminum or glass and coated with a magnetic material. Hard disks for personal computers can store terabytes(trillions of bytes) of data.

FUNCTION OF A HARD DISK

The hard disk is a secondary storage device, which is designed to store data permanently. The secondary storage devices include a large storage capacity as compared to the primary storage devices. The data stored in a hard disk is retained when our computer system is shut down.

HOW IS DATA STORED IN HARD DISK

Hard disk is common data storage used in computers. Data is stored on the hard disk in the form of 0 and 2. The part of the hard disk that stores the data is known as platter. Platters are circular disk made of a non magnetic material typically aluminum alloy, glass or ceramic and are coated with a thin layer (10 to 20nm) of magnetic material. Platters are further separated in to the tracks and sectors where tracks are concentric circles while sectors are pie shaped wedges on the track.

Hard disk stores data in the form of magnetic fields. Data is stored digitally in the form of tiny magnetized regions on the platter where each region represents a bit. To write a data on the hard disk, a magnetic field is placed on the tiny field in one of these two polarities: N-S- if North Pole arrives before the South Pole and S-N- if the South Pole arrives before the North Pole while the field is accessed. An orientation in the one direction (like N-S) can represent the '1' while the opposite orientation (S-N) represents '0'. This polarity is sensed by integrated controllers built within the hard disk.