Magnetic storage devices

For the storing of data permanently, we use magnetic storage devices. Here a magnetizing material such as iron oxide is coated over a circular plate made of metal or plastic. In these devices where disks are stored in a protective cartridge, read operation is non-destructive and write operation is destructive. Here data is represented in the form of magnetized spots in a magnetic tape. Before using a disk, it has to be formatted. It is a process where magnetic mapping of the disk surface is carried out which helps computer to go directly to a specific point on the disk during reading and writing. During first stage of formatting, tracks are created which is followed by the creation of sectors in second stage. Tracks are some concentric circles which are divided into smaller invisible pie-shaped segments. This segment is known as sector. During formatting, four areas are created in a disk. They are boot sector, file allocation table, root directory and data area. Commonly used magnetic storage devices are floppy disks or diskettes, hard disks, removable high capacity magnetic disks and magnetic tapes.