This is important to know about the hard disk for the Computer Science students. Even it’s important for everyone who uses computer, because after knowing this, you will be able to save your computer from disaster.
The computer’s hard disk comprise of one or more platters that contain all the information on your computer (Operating system, Drivers, Applications and Data).That’s right, it’s usually not a single disk. For example if a disk capacity is 120GB, Then it may comprise three platters each with 40GM capability of storing data. This all is magnetically encoded on the platters with billions of 0’s and 1’s. Information is stored on both sides of platters.
The platters are mounted on a spindle (rounded rod), which is attached to a spindle motor. In most hard drives, the spindle motor spins the hard disk platters at the speed of up to 10,000RPM (Revolution per Minute).
The hard disk has arms that move back and forth of across the surface of platters to precise locations by an actuator. A slider is attached to each arm, and an electromagnetic read/write is attached to the slider. The read/write heads read data from and write data to the platters by either converting electrical energy to magnetic energy to magnetic fields (to write data to the disk) or reversing the process (to read data from the disk).
The actuator moves all the arms across the surface of the platters in unison as a fixed assembly unit. Thus, all the arms are always located over the same respective position on each platter, forming an imaginary cylinder.
A logic board contains the electronics that control the other components of the hard disk. There are other components- cables, jumpers, connectors and so on, that connects various components, provide power to hard drive, and connect the hard drive with the motherboard.