Hard Disk of a Computer

The hard disk is an internal storage device which holds programs and data used by a computer. It consists of magnetic platters with read/write heads that float above the platters to record and play back data. In many respects, it is similar to a phonograph turntable. It is susceptible to strong jarring, which could cause the heads to physically damage the disk. The disk is enclosing in an airtight casing to keep it dust-free. HDD is a is a non-volatile, random access digital data storage device, which was first introduced by IBM in 1956.

The Microsoft Operating Systems allow a drive letter assignment such as C Drive, D Drive, E Drive etc. . This is the process of assigning alphabetical identifiers to physical or logical disk drives or partitions (drive volumes) in the root file system namespace.

Why there is no B drive?

It’s not that computers don’t have B drives. We should be aware that the primitive personal computers didn’t have hard discs. They were equipped with two floppy drives called drives A and B. Later, a hard disk was introduced and was labeled as the C drive. Other drives like the CD drive, DVD drive, flash drive and others were labeled D, E, F,G, H etc.

The basic question here arrives that how does computer write information to the hard disk. Please note that unlike a cassette, a computer writes information to the hard disk in a sequential manner. This means that one file’s a data may be scattered around the disk. When files are deleted, or even edited, blank spaces may appear around the disk.

Can a computer have more than one hard disk?

Yes. We use usually two kinds of Hard Disks today. IDE (Integrated Drive Electronics) and SCSI (Small Computer System Interface) hard drives. The IDE drives are used in PCs and SCSI in servers. Motherboards usually come with two embedded IDE ports. Each port can have two devices connected to it on the same data cable for a total of four devices. CD and DVD units are also connected to the IDE ports and counted as one of those four devices. Once we have four devices, then we can add a PCI IDE controller to have more ports to add devices. SCSI hard drives are connected to a PCI SCSI controller that will be able to accept seven devices for standard SCSI and 15 for the newer, wide SCSI.