January 5, 2011

 Hard Disk



The Hard drive also called the hard disk or fixed disk. This is the main storage for a computer and Non-volatile storage device. Every computer has a hard disk they are used to store the data files. Computers store information in two locations, First one, the computer’s RAM is used as a temporary storage location since whatever it contains is lost when the computer is powered off and Second one, Information that is stored permanently is written to the hard drive. Hard disk/Hard drive is different from RAM, because the information stays stored even if the power is turned off. Hard Drive can store a large amount of computer data in a small space and it storage provides faster access to files than a diskette.

Hard disks contain a number of magnetic platters that store information in the form of 0’s & 1’s and is stored in a series of concentric circles. A hard disk consists of one (or) more platters and several read/write heads that read and record data magnetically on platters, a stack of rotating disks inside the hard drive.  A read/write head is the device that reads the data from the disk platter into the computer.


Types of HDD (Hard Disk Drives) :
1.    IDE : Integrated Drive Electronics. it also known as PATA drives ( Parallel Advance Technology Attachment )
2.    SATA : Serial ATA or Serial Advance Technology Attachment.
3.    SCSI : Small Computer System Interface.
4.    SAS : Serial Attached SCSI.


Types of Hard Disk interfaces:

HD drives come in two main sizes, (i) 2.5" for laptops and (ii) 3.5" for desktops.

•    Desktop Hard Disk Types :- 3.5', IDE and SATA Interfaces.
•    Laptop Hard Disk Types :- 2.5', 1.8', IDE, SATA, SCSI.
•    Server Hard Disk Types :- 3.5', SATA, SCSI.

December 29, 2010

 Floppy Drive



Floppy drives are most advanced storage devices and it reads and writes data on floppy disks. Floppy Drive connects to the motherboard with a ribbon (data) cable and also power cable attached to it. Presently new computers do not have this floppy drives because USB flash drives and optical drives have replaced floppy drives in newer systems, it can be added internally to your computer (or) externally with a USB cable. It is a removable media or removable drive you can remove whatever disk is currently in the drive, and replace with another.
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