May 312012
 

A computer consists of different units such as Input Unit, Processing Unit, Output Unit etc. Among those units Storage Unit is also the one whose main function is to store data and information for future further use. There are some devices which lie under storage unit. One of those devices which lie under storage unit is Hard Disk.

When the floppies are kept one after another in a pile like structure with the help of a common spindle, all the disks move with the same speed when the spindle rotates. The cartridge is known as hard disk. For each floppy, two read and write headers are connected with the help of an arm. These arms are connected with the header actuator motors and the spindle is rotated with the help of a motor. Generally such types of floppies in a pack or disk pack contains six to eleven disks, called platters. Each platter has two surfaces so that it needs twenty two read and write heads. Each head is controlled by a circuit board. In case of exchangeable disks, the uppermost and the lowermost surfaces may come in contact with hand. Therefore, these two surfaces in such disks do not contain data. Hard disks are commonly used in all types of computers. Recent development in computer technology has facilitated computers with removable and portable hard disks which can easily removed from computers and easy transported from one place to another. These types of hard disks are generally known as external hard disks which are smaller in size but they have high data storage capacity.

Hard disk platters are constructed by metal called aluminium. These platters cannot bend or flex at all. In most drives, these platters cannot be removed. International Business Machine (IBM) calls these platters fixed disk drives for this reason. Hard disk contains the following major components which are listed below:

  1. Disk platters
  2. Read and write head
  3. Head actuator
  4. Spindle motor
  5. Logic board
  6. Configuration items
  7. Connector
  8. Bezel

In the computers of today’s time, hard disks have became an inseparable part because they are required to store data and information. Generally, people are using hard disks ranging from 80GBs to more than 7oo GBs. People are being more attracted to hard disks of high data storage capacity because they can store high amount of data easily into such types of hard disks. Hard disks are also the one which define the cost of a computer. The computers having hard disks of high storage capacity are more expensive than those which have less storage capacity. Scientists and computer experts are working very hard in order to produce hard disks having more and more data storage capacity. Some famous hard disk producers of modern era are International Business Machine (IBM), Samsung, Seagate, Sony, Phillips, Toshiba etc.