- 1. InputDevicesKeyboard, mouse, scanners,microphones,
graphicstablets, digital cameras,touch screens, and joysticks.
2. Keyboard Today, standard keyboards have 104 or105 keys. An
electronic circuit inside thekeyboard transmits the code of a
pressedkey to the CPU. QWERTY is the most used modern-daykeyboard
layout on English-languagecomputers. It takes its name from the
first sixletters at the upper left of the keyboard. 3. Keyboard 4.
Mouse 5. Touch ScreenTouch Screen is a type of display screenthat
has a touch-sensitive transparent panelcovering the screen so that
it can recognizethe location of a touch on its surface. 6. Light
PenA light pen is a form ofa light-sensitive wandused in
conjunctionwith a computersmonitor. It allows theuser to point
todisplayed objects ordraw on the screen ina similar way to atouch
screen but withgreater positionalaccuracy. 7. Graphics Tablet (Pen
Tablet)A tablet is an alternate type of input devicethat can be
used in place of a pointingdevice. It enables you to enter
drawingsand sketches into a computer. The tabletconsists of two
parts, a flat surface fordrawing and a pen or stylus that
isprogrammed to work with the tablet. 8. Concept Tablet and
ConceptKeyboard Concept tablets and keyboards arewidely used for
special purposecomputers when fast input is needed.They are ideally
suited for selecting from alimited range of choices, such as
takingorders in a fast food restaurant. 9. WebcamA webcam is
essentially a small camera that is connectedto a computer, either
directly or wirelessly, and gathers aseries of images that are
viewed in real time on thecomputer screen or over a network,
especially over theInternet. 10. Scanner 11. Microphone 12.
Joystick 13. OutputDevices 14. MonitorThere are two main types
ofmonitor:Flat panel monitors and cathoderay tube (CRT) monitors.A
flat panel monitor uses a liquidcrystal display (LCD) instead of
acathode ray tube to displaydata. LCD monitors occupy lessspace,
consume less energy, andare much lighter than CRTmonitors. Many
monitorcompanies have alreadystopped producing CRT monitors. 15.
MonitorA monitor connects to either a VGA (videographics array) or
DVI (digital visual interface)port on a video card. Both devices
shouldsupport the same type of connection. 16. PrinterDepending on
the printing technologies, printersare divided into three main
categories: impact,ink-jet, and laser printers. Ink-jets
(bubble-jets) printers: Ink-jet printers usetiny jets to spray ink
onto the paper. Laser Printers: Laser printers produce high
printquality at high speed. They are called laserprinters because
they use a laser beam toproduce an image on a drum. Dot matrix
printers push a row of pins through anink ribbon onto the paper.
Dot matrix printers areused for cheaper, low quality Printing. 17.
PrinterA dot-matrix printerA laser printer An Ink-Jet Printer 18.
PlotterA plotter is an outputdevice similar to aprinter, but for
largerimages. Plotters useeither pens orelectrostatic chargesand
special chemicalsto print an image. 19. Speakers and Headphones 20.
DataStorageDevices 21. A storage device is a hardware device
designed tostore and retrieve information.Types of storage devices
There are two types of storage devices:temporary storage devices
and permanentstorage devices RAM, CPU caches, and CPU registers
aretemporary storage devices. Permanent storage devices hold
information untilit is deleted or overwritten. Depending on
thetechnology, secondary storage devices can bedivided into three
categories: magnetic, optical,and flash storage. 22. Hard Disk
Drive (HDD)A hard disk drive (HDD), commonly referredto as a hard
drive, hard disk, or fixed diskdrive, is a device that stores
digitallyencoded data on rapidly rotating platterswith magnetic
surfaces. Hard disks are themain large data storage area inside
yourcomputer. Hard disks are used to store yourprograms and data.
They are much fasterthan most other types of storage deviceand can
also hold much more data. 23. Hard Disk Drive (HDD) 24.
FormattingWhen a hard disk is manufactured, theplatters are empty,
so your computercannot read them. The process of creatingthe tracks
and sectors on the platters andpreparing the disk for use is
calledformatting. 25. Hard Disk Drive (HDD) 26. Solid-State Drive
(SSD)A solid-state drive is astorage device thatuses
solid-statememory to storedata. In contrast withtraditional
harddrives, solid-statedrives contain nomoving parts: nospinning
platters, nomoving heads. Dataare split into word-lengthpieces
andstored in memory. 27. Why SSD?Solid-state drives may be
preferred over traditionaldisk drives for a number of reasons: The
first advantage is the speed of operation. The second advantage is
that breakdown is lesslikely. Because there are no moving parts,
lesscan go wrong mechanically and dropping thedrive is less likely
to cause damage to the data. 28. Floppy Diskette (FDD)Floppy disks
are also called diskettes. Theyare very slow compared to hard disks
orCD-ROMs and hold a smaller amount ofdata (1.44 megabytes).Floppy
disks are also quite fragile. Floppydiskettes are not used any more
andmodern computers do not come withfloppy disk drives. 29.
Magnetic TapeComputers can read and write data on specialcartridges
of magnetic tape. A magnetic tapecartridge looks like a music
cassette. 30. CD-ROMA CD ROM (compact disc-read-only memory) is
atype of optical diskcapable of storing largeamounts of data up to
1GB, although the mostcommon size is 700 MB. 31. CD-ROM 32.
DVD-ROMIts main uses are videoand data storage. DVDsare of the
samedimensions as compactdiscs (CDs) but arecapable of storing
muchmore data (about 4.7 or8.5 GB of data on oneside, or 17 GB on a
diskwith two sides) 33. Double Layer DVD8.55 GB 34. Flash Disk 35.
Portable Hard Drive 36. SD (Secure Digital) Card 37. Blu-ray
DiscThe Blu-ray disk is a highdensity optical storagemedium.The
format offers morethan five times the storagecapacity of
traditionalDVDs and can hold up to25GB on a single-layer discand
50GB on a dual-layerdisc. Recent developmentby Pioneer has pushed
thestorage capacity to 500 GBon a single disc by using 20layers.
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