- Input Unit
- Output Unit
- Processor
- Control Unit
- Arithemetic and Logic Unit
- Registers
- Data Bus
- Address Bus
- Control Bus
- Primary Memory
- Secondary Memory
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A data storage device is a device for recording information. Recording can be done using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs. A storage device may hold information, process information, or both. A device that only holds information is a recording medium. Devices that process information may either access a separate portable recording medium or a permanent component to store and retrieve information.
Electronic data storage is storage which requires electrical power to store and retrieve that data. Most storage devices that do not require vision and a brain to read data fall into this category. Electromagnetic data may be stored in either an analog or digital format on a variety of media. This type of data is considered to be electronically encoded data, whether or not it is electronically stored in a semiconductor device, for it is certain that a semiconductor device was used to record it on its medium.
Types of storage Devices:
Floppy diskette: A Floppy Disk Drive, or FDD or FD for short, is a computer disk drive that enables a user to save data to removable diskettes. Although 8" disk drives were first made available in 1971, the first real disk drives used were the 5 1/4" floppy disk drives, which were later replaced with 3 1/2" floppy disk drives. Today, because of the limited capacity and reliability of floppy diskettes many computers no longer come equipped with floppy disk drives and are being replaced with CD-R, other writable discs, and flash drives.CD-ROM disc: Short for Compact Disc-Read Only Memory, CD-ROM drives or optical drives are CD players inside computers that can have speeds in the range from 1x and beyond, and have the capability of playing audio CDs and computer data CDs. Below is a picture of the front and back of a standard CD-ROM drive.CD-R disc: Alternatively referred to as CD-WO (Write once) or WORM (Write Once Read Many) drive. CD-R is short for CD-Recordable and is a writable disc and drive that is capable of having information written to the disc once and then having that disc read many times after that. If the data is not written to the disc properly, has errors, or has the incorrect information that disc or portions of that disc cannot be erased and is often jokingly referred to as a coaster.
A CD-R disc is coated with a photosensitive organic dye that allows a user to record information. Once the CD-R disc is placed within the computer, the recording process begins. The laser inside the drive heats the dye to reveal areas that diffuse the light like a traditional CD pit. The CD-R drive does not actually create pits on the CD; instead the burner creates reflective sections on the CD causing the computer's CD-ROM laser to interpret it as a pit. Once a CD-R disc is finished recording, the CD will be able to be used in any standard CD-ROM, CD-R, CD-RW, or DVD drive. Although, there were issues with the first revision DVD drives reading CD-R discs.DVD-RM: Short for Digital Versatile Disc-Read/Write, DVD-RW is an approved standard by DVD Forum and, much like CD-RW, is a technology that enables a user to read and write to a DVD-RW or DVD-R disc several times. DVD-RW drives are capable of recording to DVD-R and DVD-RW discs, also known as DVD-5 and DVD-10 discs.
Note: DVD-RW discs are compatible with most stand-alone DVD players and computer DVD-ROM drives.USB flash drive: Alternatively referred to as a USB flash drive, data stick, pen drive, keychain drive and thumb drive, a jump drive is a portable drive that is often the size of your thumb that connects to the computer USB port. Today, flash drives are available in various sizes including but not limited to 256MB, 512MB, 1GB, 5GB, 16GB, and beyond and are widely used as an easy and small way to transfer AND store information from their computer.Hard disk drive: Alternatively referred to as a hard disk drive and abbreviated as HD or HDD, the hard drive is the computer's main storage media device that permanently stores all data on the computer. The hard drive was first introduced on September 13, 1956 and consists of one or more hard disk platters inside of air sealed casing. Most computer hard drives are in an internal drive bay at the front of the computer and connect to the motherboard using either ATA, SCSI, or a SATA cable and power cable. Below, is an illustration of what the inside of a hard disk drive looks like for a desktop and laptop hard disk drive.Zip diskette: When referring to computer software or software compression, zip is a file extension associated with such compression programs as WinZip or PKZIP. Zip files are commonly a collection of software files or programs compressed into the one zip file.
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