Data Storage Devices

Disks are currently the reigning monarch of portableAlready, the latest USB drives have a capacity of 12
data storage devices and are very popular withGB, which is about three times higher than a DVD.
computer users. First introduced about 20 years ago,Those with a capacity of 1 GB to 8 GB are available
the optical disk technology has matured over timequite cheaply. USB drives offer many benefits over
and become extremely reliable. Their costs haveother devices. They have no moving parts, so there
crashed too, with each disk costing almost as muchis no friction or energy consumption. They are quite
as a floppy diskette. Also, they have capacities assmall and easily transportable. You can copy and
high as 4.6 GB which is more than sufficient for therecopy data on them thousands of times without
data storage needs of most computer users. Thereany problem. As their capacities go up and prices
is hardly any other storage device available in thecrash, USB drives are emerging as the storage
market today that gives such a fantastic combinationtechnology with a bright future. Already, Sony has
of price, reliability and capacity as optical disks.launched a laptop in the market that has a 60 GB
Optical disks are of two types: compact disks (CDs)flash-memory drive instead of a hard disk.
and digital video disks (DVDs). The former were thePortable Hard Disks
first ones to be introduced, with a capacity of aboutThese are identical to the fixed hard disks found
700 MB. CDs are today the portable storage mediascrewed inside a computer CPU, but made portable.
of choice for most computer and laptop users. SomeThe manufacturers try to build them as light and
years later, DVDs arrived in the market. These havereliable as they can, and that is the reason why the
a capacity of 4.6 GB that is more than sufficient tomarket for portable hard drives is growing at a
hold a full-length Hollywood movie.healthy rate.
The optical disks are used in tandem with an opticalThese disks are small and thin enough to fit inside a
drive that is attached to a computer CPU. Once ashirt pocket. They connect to a computer CPU
disk is inserted into the drive tray, it is spun at a highthrough the USB port. Most of these come with an
speed by the drive motor. A read / write head thatautomatic data-backup software that takes
can move back and forth reads the data that residesautomatic backups of files. The main benefits of
on the disk surface as a pattern of microscopic pits.portable hard disks are their random access and huge
This is done by the medium of a laser emitted bystorage capacities of up to 500 GB.
the head which can not only emit it but also read itTape Drives
once it bounces back from the disk surface.Tape drives have been around for many decades
USB Drivesnow and are still going strong. A tape drive system
USB (Universal Serial Bus) drives are the latestuses the tried-and-trusted magnetic tape technology
data-storage devices to hit the market. These doto store data. It has two main parts — the
not need stand-alone drives like optical disks. Instead,drive and the cartridges. The latter are made of
you simply insert the drive into the USB port of aplastic and carry a long and thin ream of magnetic
computer or laptop, and it is ready to be used. Dataplastic tape inside. This is the actual data-recording
can be saved to or extracted from the drive by thesurface.
simple expedient of “drag and drop.” The USBThe cartridge is inserted into the tape drive where
drives, which are small enough to be dangled by thethe spools are spun by the drive motor, moving tape
end of a key chain (hence also called “key chainfrom one spool to another. The tape moves past a
drives”) are made up of a tough protective plasticread / write head, making full physical contact. The
shell inside which exists a flash-memory chip. All datahead has an electro-magnet that accesses and
resides inside this chip. There are no moving parts ormodifies data on the tape. A tape drive gives
a motor.sequential access to data.
The USB drive technology is maturing very quickly.