Computer Literacy BASICS: A Comprehensive Guide to IC3, 3rd

Transcription

Computer Literacy BASICS: A Comprehensive Guide to IC3, 3rd Edition, page: Mod1-27
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Q)
Estimated Time:
2 hours
LESSON 2
Input, Output, and
Processing
• OBJECTIVES
• VOCABULARY
Upon completion of this lesson, you should be able to:
audio input
•
Ident ify and describe standard and specialized input devices.
biometrics
•
Ident ify and describe standard and specialized output devices.
digita I camera
•
Ident ify and describe how input and output devices are connected
to the computer.
expansion slot
•
Consider computer performance factors.
inkjet printer
FireWire
input
keyboard
• DATA FILES
laser printer
You do not need data files to complete this lesson.
modem
monitor
mouse
output
plug-and-play
pointing device
port
printer
scan ner
trackball
Universal Seri al Bus (USB)
Modl-27
User: Ali Kaba <akaba@harmonytx.org>
Page 7 of 10
MDdl -28
MODULE 1
Computing Fundamentals
~ VOCABULAR Y
input
However, it need, help. II/Pil i , wh.ich is data or instructions, must be entered into
When it comes to processing data, it is the computer that does all of the work.
key boa rd
the computer and then stored temporarily or permanently on a storage media device.
To tum the data into inform.ation. it must be processed. The central processing unit
(C PU). which you learned about in Lesson I. processes tbe data . After the data is
processed. it is ",Presented" to t he user thro ugh an output device.
Standard Input Devices
Input devices cmlble you to enter data and commands into the computer, and output
deyices enable the computer to give you the results of the processed data. Some
devices perfonn both input and output functions, slich .as the fax machine and
fax modem. You use these devices to send (outpUI) ;:Ind receive (input) data over
communications media.
The type of input device you use is determined by the task you need to complete.
An input device can be as simple as the keyboard or as sophisticated as those used
for specialized applications such as voice or retinal recognition.
Keyboard
The keyboard is the mosl commonly used input device for entering IlLII1leric and
alphabetic data into a computer. Lf you are going to use the compuler etlicielltly, it is
impommt that yOlt learn to type. Most of the keyboards provided with desktop com·
pll ters are enhanced. An enhanced keyboard has 12 function keys .along the lOp, two
All keys, two Clrl keys. and a set of directional/arrow keys between the typing area
and the numeric keY]Jad.
Some keyboards. sllch as the one shown in Hgure 2- 1, have multimedia hot
keys that enable you to access e-mail and the Internet, adjus;t speaker volume. and
have other features such as:l zoom slider. This device makes it easy to zoom in for a
closer look .at documents, spreadsheets, pictures, maps, and Web pages .
@
EXTRA FOR EXPERTS
Need more space on your desk?
Consider the Near ly Indestructible
Keyboard {N!K)- it is flexible, can
be rolled up and put into a briefcase, and even washed with soap
and water or a spray cleaner (www.
dovecoteglobal.comlnik. fltmn.
FIGURE 2- 1
Enhanced keyboard
Not all keyboards. however, are traditional. Some other popular types of
keyboards arc:
•
Ergonomic: This type of keyboard is designed to provide users with more
natural. comfortable hand. wrist. and ann positions.
•
Cordll!Ss or wireless: TIlis is .a battery-powered keyboard that trallsmits data
using wircle~s technology.
Page 8 of 10
LESSON 2
Input, Output, and P,oce"ing
•
Speciali:ed: This keyboard h::t.<; specia lizoo keys that represent items such as
those used in fas t-food rcslllu rWl l S.
•
Secllrity: Th is keyboard provides security fe."uurt'S such as a biometric fingerprint reader. nmgnctic stri pe, and s mart card readers (sec J' jg ure 2-2).
Modl -29
Biometric
fingerprint
reader
FIGURE 2-2
•
FO/llable or fl exible: An easily lransponed keyboard prinwrily used with PDA
and pocket PC-type devices. thi s type of keyboard has a SOfl louch and is w ater
res ist.lIlt (sec Figure 2-3).
FIGURE 2-3
•
Keyboard with tingcll'ri nt reader
Foldable keyboard
ulser \lirlual keyboard : Packaged in a case smaller Ih~ a soda can. a hlscr beam
is used
10
ge ne rate a full- size laser keyboard. This keyboard eas ily connects to
any person .. ] computer, including Macintosh, BlackBerry or ocher smart pho ne,
and most ot her handhe ld devices (sec Fig ure 2-4).
FIGURE 2-4
Laser vi rtual keyboard
Page 9 of 10
MODULE 1
Modl-30
Pointing Devices
A p oilltillg device is an inp ut device th~ll allows you to position the pointer on the
screen. TIle pointer Gill have scveml shapes, but the most common is an arrow. You
use a pointing dc\"ice to move the pointer: select objects, such as text or graphics: and
• VOCABULARY
pointing devi c~
mouse
click buttons. icons, menu items, and links. The following sections discuss several
pointing devices.
Mouse
The //IO llse is the most commonly used poiming device for personal computers. Jt
moves on a flat surface and controls the pointer on the screen. TIle mouse fits conveniently in the palm of your hand. Yo u can use any of the following fouT types of mice:
•
Mechanical: This type of mouse has a ball located on the bottom that rolls
around on a flat surface as the mouse is moved. Sensors inside the mouse dete rmine the direction and distance of the movement. A mouse pad genemlly is used
wi th a mechanical mo use.
•
OpTOlIlecJumica/: This mouse is the same as a mechanical mouse, but uses optical sensors to detect motion of the ball.
•
Optical: An optical mouse (see F igure 2-511) uses a laser to detect tbe mouse' s
move m ent. 0 p1iclll m ice h ave no mechani c al moving part~. T hey respon rl more
q uickly and precisely than mechanical and optomechanical mice.
•
Wirde.~s: A wLrelcss mouse (see Figure 2-Sb) is a battery-powered device that
relies on infnred or ntdio waves to com municate with the computer.
Receiver
(al
(bl
FIGURE 2-5
(a) Optical mouse (b) Wireless mouse and receiver
Most miee have two or three buttons; some have a wheel. You use the left button
for most mouse opemtions. Genemlly, clicking the right button d isplays a shortcut
menu. After you pl.ace the on-screen pointer where you want it, press a button on the
mouse. This causes some type of action to take place in the computer: the type of
act ion depends on the program. Use the wheel to scroll or zoom a page.
You use the mouse to accomplish the followi ng techniques in most software
programs and Web pages:
•
Poimillg: Plac ing the oil-screen pointer at a designated location
•
Clicking: Pressi ng and relcasing the mOllse button to select a specific location
within a document
•
Draggil1g: Pressing down thc mouse button and moving the mouse whilc
continuing to hold down the button to highlight :I. selected portion of text
Page 10 of 10
LESSON 2
•
Input, Output, and Processing
Modl-31
Double-clicking: Pressing and releasing the mouse button two times in rapid
succession to select a word
•
Triple -clicking: Pressing and releasing the mouse button three times in rapid
succession to select a paragraph
•
Right-clicking: Pressing the right mouse button to display a menu
•
Rorate I'i"'heei: Rotate wheel forward or backward to scroll vertically
•
Tilt wheel: Press the wheel right or left to scroll horizontally
Trackball
The IrackbaJ[ is a pointing device that works like a mouse turned upside down: the
ball is on top of the device. See Figure 2-6a. You usc your thumb and ringers \0
operate the ball, thus controlling the pointer on the screen. A trackbal l is a stationary
de ... ice and is a good altemative to the mouse whcn you nave limitcd desktop space.
Some trackballs arc built into the keyboard. See Figure 2-6b.
lal
FIGURE 2- 6
• VOCABULARY
Inlckball
Ibl
(a) Trackball on a mouse (b) Trackball on a keyboard
Touchpad
A common feature on l.aptop computers is tbe touchpad. a pointing device wiib a
specialized surface that can conven the motion and position of your fingers to a
rel(Jtive position on screcn. Touchpads are a common femme of laptop computers
and can be fou nd on personal digital assistants (PDAs) and ponable media players.
Pointing Stick
Many notebook computers contain a pointing stick- a pressure-sensitive device that
looks like a penc il erascr. It is located on the keyboard. generally betwecn tne C. H.
and B keys. See Figure 2-7. It is moved with the forefinger, while the tnumb is used
to press related keys. In a confi ned space. a lot of people find 11 pointing stick more
convenient than a mousc. IBM popu larized tbis device by introducing the TrackPoi nl
on its 1l1inkPad notebooks.
Page 1 of 10
Modl -32
MODULE 1
FIGURE 2-7
Pointing stick
Audio Input
IJ VOCABULARY
A udio il/pllt is the process of inputting sound into the computer.TIlis could include
audiu input
speech, sound effects. and music. Audio in put devices include microphones. COl
output
DVD players. radios. and other hardware such as electronic kcytmards. Voice input is
a category of audio input. Voice-recognition devices are used to "speak" commands
monitor
into the computer and to ellier text. These devices usually are micropbones. The
computer must have some lype of voice-recognition software installed before you
can use a yo ice-recognition device. Directory assisHUlce is a type ofyoicc-rccognition
technology. as ar~ devices that dis:lbled persons use to command wheelchairs and
other objects that make them more mobile.
~
1·1.1 .5
Standard Output Devices
Olltput is data that has been processed into a useful format. Examples of output are
printed text, spoken words, music, pictures, video, or graphics . The most common
output devices arc monitors and printers. Output devices display information.
Monitors
Desktop computers typi ca lly use a monitor as their dis play device. The screen is part
of the monitor, which also includes the housing for its electrical components. Screen
output is called soft copy because it is temporary.
Computer mOllitors come in many varieties. The cathode ray tube (CRT) was
one of the earliest types of mon itors. This type of monitor is similar to a standard
televisioll and can be either monochrome or color. A monochrome monitor screen has
a one-color display. which can be whjte. green, or amber. Most of today's monitors
are color monitors, which display thousands of colors. CRT monitors are available in
various sizes, with the more common being 17-, 19-, and 21 -inch. See }"igure 2-8<'1.
Some of the newest monitors are avai lable in sizes lip to 30 inches or more.
Flat-pallel monitors come in two varieties: liquid crystal display (LCD) and gas
plasma. Both types of monitors are more expensive than CRT monitors. They take
up less space. however, and are much lighter in weight.
LCD panels produce an image by manipulating light withi n a layer of liquid
crystal cells. See Figure 2-8b. Until recently, LCD p:mels were uscd p"imarily on
notebook computers and other mobi le devices such as cell phones and PDAs. 1n
1997, several manufacturers started producing full -size LCD panels as alternatives
to CRT monitors.
Page 2 of 10
LESSON 2
Input, Output , and Processing
Modl-33
Gas plasma technology consists of a tiny amount of gas that is activated by an
electrieal charge. See F igure 2-8c. The glls illuminntcs mini.aturc colored f1uoresccnt lights arranged in a panel-like screen. These monitors have a brilliant color
display and are available in sizes up to 60 inches or more.
la)
FIGURE 2-8
(b)
(e)
(a) CRT (b) LCD panel (e) Gas plasma display
Printers
Pri"ter~ arc used to produce a paper or hard copy of the processing results. Printer
output is called hard copy because it is pemlanent. Several types ofprintcrs arc available. with significant differences in speed. print quality. price, and special feature.s
When selecting a printer, consider the following features:
•
Speed: Printer speed is measured in pages per minute (ppm). The number of
pages a printer can print per minute varies for text and for graphics. Graphics
print more slowly than regular text.
•
Prim qualiTY: Prillt quality is measured in dots per inch (dpi). The higher the dpi.
the higher the resolution or print qualit y.
•
Price: The price includes the original cost of the printer as well <IS what it
costs to maintain lhe printer. A good-quality printcr can be purchased very
inexpensiVely; however, a high-output system can cost thousands of dollars. The
ink cartridges and toners need to be replaced periodically. Printers are classified
as either impact or nonimpact. Impact printers usc a meehani~m that actually
strikes the paper to !"onn lettcrs and images. Dot matrix printers are impact
printers. Nonimpact printers form characters without striking the paper. The two
most popular types of printers. laser printers and inkjet printers, are examples of
nonimpact printcrs.
t VOCABULARY
printer
laser printer
Laser Printers
A la~er prillter produces images using the same technology as copier machines.
The image is made with a powdery .substance called toner. A laser printer produces
high-quality output. The cost of laser printers has come dO'Nn substantially ill recenl
years. Color laser printers, however. are still expensive. some costing thousands of
dollars. See Figure 2-9.
Page 3 of 10
MODULE 1
MDdl-34
Output tray
1~
beam
__--::::::____·TO""catridge
guide rollers
Manuill feed
picKup roller
SIMMs (RAM)
Fixi ng ,"1111''''; ~~
Input paper _ _
cassette
Printing process
Paper handl ing
Controlling the printer
T he laser beam ~etches'
Mosllaser primers allow
paper to be fed either
automatically or
While laser printers
usually include a control
panel, most of the
manually. Manual
controlling of t he
printing process is do ne
from the computer by
the image on a
photosensitive drum.
T he developing cylinder
picks up a fine blacl:
powder ca lled toner,
which is attracted t o the
fee d ing allows
envelopes, heavier paper,
and nonstandard sizes of
etched image on the
paper t o be used .
softwa re.
surface of the d rum.
When the paper comes
into contact with the
drum holding the image,
the toner is transferred
to the paper, creating the
01 the page.
image
FIGURE 2-9
Howa laser printer works
Inkjet Printers
• VOCABULARY
illkjet printer
An illkjet primer provides good-quality color printing for less expense tllan a laser
printer. See Figure 2-10. Inkjet printing, like laser printing, is a nonimpact process.
Ink is squirted ti·om nozzles as they pass over the media. Unlike earlier vcrsions of
the inkjel printer, newer versions c an use regular photocopy papcr.
Page 4 of 10
LESSON 2
Modl -35
In put tray
Contro l panel
Carriage
Output tray
Printing process
Paper and Ink
Controlling the printer
During ptinting, the
paper passes below
1he carriage, which
hol ds the ink
ca rtridges and print
head. As the carri.age
moves back and forth
over the paper, ink is
sprayed in minute
droplets onto the page.
Inkjet printers u se
single sheets of paper.
Since plain paper can
be too absorbent for
inkjets, manufacturers
recomme nd special ink·
jet paper, w hich has a
~ arder surface.
The contro l panel
includes the oni off
switch, an online
button, and an LCD
panel that displays
messages and menus.
FIGU RE 2-10
How an in kjet pri nter works
Speakers
Speakers are also a type of output device . Spe akers and headsets generate sound,
such as mmic or ins tructions on how to comple te a tuto rial. Indi viduals use headsets
o r earpho nes to hear the music o r othe r voice output privatel y.
Page 5 of 10
MODULE 1
Modl -36
Specialized Input Devices
1-1. 1.6
A variety of other input devices arc also available, most of which are used for
specialized applications. The following section describes these input devices.
Digital Cameras
• VOCABULARY
The pictures taken with a digital call/era arc stored digitally and then transferred to
digital Cllme m
the computer's memory. Digital cameras usc a variety of storage media to store the
images, including flash memory cards, memory sticks, USB keys, m i lll~d i scs, and
other solid-state storage devices. After the pictures are transferred to the computer.
they can be viewed quickly and any imperfections can be edited with photo-editing
@
EXTRA FOR EXPERTS
You do not need a digital camera
to have digital pictures. Many
photo labs can deliver photos
via the Internet or on a disc in
digital format.
software.
Video input is the process of capttlring full -Illotion images with a type of video
camera and then saving the video on a storage medium such as a hard drive, CD, or
OVD. After the video is saved, you can view .and edit it. A digital video (DV) camera
records video as digital signals: some cameras also capture still images, Some are
just a little klrger than 11 crcdjt card. See .' igure 2-11 . A PC video camera is 3typc of
digital video camera that allows the user to send live images over the internet. make
video telephone calls. and send e-mail messages with video attachments.
FIGURE 2- 11
Miniaturized digital video camera
Webcams arc video-capillring camems th~lt are connected to computers or to
computer networks and display images through the World Wide Web. Generally.
these c.ameras arc used for videocollferencillg 3nd or monitoring. WebC:UliS are also
used for security purposes. monitoring both movement and sound.
Game Controllers
The joystick Rnd wheel are types of pointing devices. Joysticks and wheels, such as
the ones shown in Figure 2-12, most often Rre used for games. Th ejoy stick consists
of a plastic or metal rod mounted on a base. You can move thc rod in any direction.
Some joysticks have switches or buttons that c an input data in an onfoff respo nse.
A wheel is a steering-wheel type of device used to si mulate driving a vehicle. Most
wheels also include foot pedals used for braking and acceleration ~lctiom.
Page 6 of 10
LESSON 2
I')
Modl -37
Ib)
FIGURE 2-12
(a) Joyst ick (b) Wheel
Scanners/ Bar Code Readers
Sea/m en are devices that can change image.." into codes for input to the computer.
Scanners are available in various sizes and lypeS, including Ihe following:
•
III/age
scanller.~:
t VOCABULARY
scanner
These devices convert images into an elcctronic form that can
he stored in a computer's memory. The image can then be manipulated.
•
Bar code scanllers: This type of sc~mner reads bar lines that are printed on prodlIcts (for example. in a grocery store or departmcnt store). Sec Fi gu re 2-1311.
•
Magnetic scanJlers: These devices read encoded information on the bad: of
c redit cards. The magnetic strip on the back of the cards contains the user's
encoded account number.
•
Wireless SCl/Jlllers: A Bluetooth barcode scanner lIses Bluetooth wireless technology to SCllll data. such as from 11 hospital bracelet. and transmit it to 11 computer. Sce Figure 2-lJb.
•
Optical cJwracler recognition (OCR) and optical mark recognitioll (OMR):
111cse devices usc a light source to read characters. marks. and codes: Ihe data
is then converted into digital data. Banks usc OCR technology to scan checks.
Commonly known as Sc:mtrons, schools and other organizations usc OM R for
testing purposes.
I')
FIGURE 2-13
Ib)
(a) Optica l scanner (b) Bluetooth scanner
Page 7 of 10
Modl-J8
MODULE 1
Touch Display Screen
The touch display screen, shown in Fig ure 2-14, is a special screen with pictures
or shapes. You li se your fingers to "point" to the desired object to make a selection.
You can find theie screens in many public pl.aces sllcn as airports, hotels, banks.
libmrics. delivery services, and fast - food restaurants. Many mobile devices have
touch screens.
FIGURE 2- 14 Touch screen on a handheld device
Stylus
A stylus and digital pen are pen-like writing instruments. See F igure 2-1 5. These
II PDA or other mobiLe device
or to usc the pen as a pointer.
devices allow you to input information by writing on
Page 8 of 10
LESSON 2
FIGURE 2- 15
Input, Output , and Processing
Modl-39
Stylus for mobile device
Environmenta l Probe:; and Sensors
Environmental monitoring in many indus.tries and companie s is a critical component
o f stabil ization in the work area. Workers c:m use environmenfal probe.~ and sensor.\·
with .a standard \Veb browse r, such as Internet Explorer. to view clements such as
the tempcmture and humidity of a remote environment. smoke detector readings.
pollution control readings, and so on. Indu stries such as farming, tropical fish production, moisture monitoring. and warehouse security use environmental probes and
selL~ors .
Remote Controls
RemOTe conrrols. also a type of spec ialized inplll device, are used for numerous
standard applications, such as television, lights, fan s, and soon. Ind ustry and business
also use remote controls for various applications. For example, a construction worker
can use a remote comrol to control a crane. or a warehouse worker can have a remote
cOlltrol for a product cart.
Security Devices
Consider the following scenario: You are going on a two-weck vacation to Tahiti and
Bora Bora- you are packed and ready to go. but you do not need a wallet or credit
cards. You use your fingerprint as an input device to pay for all of your expe nses.
In infonTI:ltion technology. h iom etric .~ is an authcntic:ltion teChnique using
automated methods of recognizing a person based on a phys io logical or bebavioral
characteristic . Biometric devices consist of a reader or scanning device and software
that converts tbe scanned information into a digital format . The scanned information
then is compared to a database of stored bio metric data.
• VOCABULARY
biomet ri cs
Page 9 of 10
MDdl-40
MODULE 1
Severnl types of biometric identification techniques ex ist. Some of the morc
com m o n usc a perso ll 's fingerprints , facc , handwriti ng. or voice. Other less co mmon
techniq ue.. are retina (analysis of the capillary vessels located at the bac k of the
eye), iris (analysis of the colored ring sunuunding the eye's pupil), hand geometry
(analysis of the s hape of thc hand and length of Ihe fingers). and vei n \a n.alysis of
pattern of veins 011 the back of the hand and the wrist}.
The process or thc way in which biometric technology works. however. is
basically the same for all identification techniques:
•
Enrollmem: The user enrolls in the system by establishing a baseline measurement for comparison.
•
Sllbmis.~ion: The user presents biological proof of his or her idclltity to tne
c apture systcm.
•
Verificatioll: Thc system compares tne submitted sample with the stored
sample.
Privacy and civil liberties advocates, however, are concerned about the
widespread adoption of biomctric systems. They argue that by using biometric data,
un authorized parties can access someone's dat~l witnout their conscllI and link it to
other information, resulting in secondal)' uses of the information. T nis erodes tne
users' personal control over their private infonnation. On the other hand, biometrics
can also be applied to private security. For ex.ample, several compani e~ now offer
biometric compute r keyboards and USB nash drives with finge rprint authentication
that can be used for personal applications. (Flash drives were discussed in Lesson I.)
Sec Figure 2-16.
(a)
FIGURE 2- 16
(b)
(a) Biometric keyboard scanner (b) Fingerprint scanner
Vi dual Devices
Similar to the la.s~r virtual keyboard mentioned earlier, virtual de vices usc the synchronized positiuning of light-emitting and sensing devices to detect user input.
Figure 2-l7a shows a virtual computer keyboard and Figure 2-17b shows a virtual
piano keyboard.
Page 10 of 10
LESSON 2
(0)
Modl-41
(b)
FIGURE 2- 17
(a) Virtual computer keyboard (b) Virtual piano keyboard
Touch-Sensitive Pads
llle louch -sensitive pad on a portable device, such as an iPod, enables you to scroll
through a list adjust the volume. play music. ,'iew videos or pit:1Ures. and customize
settings.
Input Devices for the Physically Challenged
A variety o f special input dC\'ices are available for the physically ch'lllenged.
Following arc some examples:
•
Some keyboards can be operated with one hand or with the feet.
•
A progrum called Camera Mouse enables users 10 use a Wcbcam and control the
mouse pointer by moving their heads.
•
A human-computer interface uses eye control to move a pointer and make
selections.
•
A joystick compute r mouse can be operJled with
tongue for people with little or [}o head moveme nt.
•
Voice input devices allow visually impaired. blind. and physically challc ngcd
individuals to more easily interact with computers.
•
A compute r di spl ay screen is sensitive to hUlllan to UGh and allows the user to
intcmct with the computer by touching an active area or a targe!. or to control
d ata such as pictures or words on Ihe screen.
I ~c lip.~.
chin. or wilh the
Specialized Output Devices
Simi lar to speci.. lizcd input devices. a varie ty of s pecialized output devices arc .. Iso
available:
•
Pmjec/ors: A data projector projects the computer image onto a screen: this is
mostl y used for prcscnt.. tions.
•
Fax machilles {lillI/ax moJems : A fax machine and fax modem tmnsmit and
receive document s over a telephone line or through a computer.
•
Mil iti/ilne/ioll primer. A multifunction printer combines various output options
suc h us printjng. scanning. copy in g. and faxin g.
•
COllI/vi devices/robots: The field of robotics is dclincd as the study, design. lUld
lISC of robot systems for m~mufacturin g. Some of the typical applic:.t!ions of robots
includc tcsti ng. product inspection, painting, assembly, packagi ng. and p<linting.
1·1.1.7
Page 1 of 10
MODULE 1
MDdl -42
Specialized Printers
Impact printe rs, such as the dot matrix and line printer, have been around for a long
time. Dot matrix printers transfer ink to the paper by stri kin g a ribbon with pins. The
higher the number of pim. (dpi), the better the resolution or output. The mechanism
that act ually does the printing is called a printhcad. The speed of the dOl matrix
printer is measured in ehamelers per second (c ps). With the reduction in cost of
laser and ink jet printers, dot matrix printers are used less often toclay. A variation of
the dol matrix prin ter is the line printer. This type of high-speed printer is attached
primarily to large computers such as m ainfmmes or rnidnmgc servers.
Scycm] other types of specialty pri nters are available. Some examples are:
•
Thermal: A thermal printer fonns characters by heating paper. The printer
requires special hem-sensitive paper.
•
Mobile: A mobile printer is a small. battery-powered printer. primarily used to
print from a note book computer.
•
Ulbe! {wd poslllge: A label printer prints labels of various types and sizes on an
adhesive-type paper: a postage printer is a special type of label pri nter. This lype
of printer contains a built-in digit~11 scale and prints postage stamps.
•
PlotTers/large-f()rmat: Engineers, architects. and graphic artists use plotters and
large-fonn at printers for drawings and drafting output.
Output Devices for the Physically Challenged
Similar to input devices for the physically challenged . output devices are also
available. Following are some eX3Inples:
•
Screen magnifiers: T hese devices contain a range of magnifications and a
variety of fonts llnd are used to e nlarge the information displayed on the computer screen.
•
Screen readers: A screen reader assists people who Me blind or otherwise visllally impaired. A speech synthesizer genera lly is used to read the screen content.
Some screen readers can also read sca nned documents.
•
Voice synThesizers: Speech synthesis is the computer-generated simulation of
human speech. A voice cha nges written computer text into synthetic speech.
This technology is useful especially for people with limited sight.
Connecting Input and Output Devices to the
Computer
1-1. 1.8
Input and output devices must be connected to the comp uter. Some devices connect
to the computer through a physical co nnection. sllch as a port. For instance. you can
plug the cable for a physical device into an existing pon located on the back or front
of the computer. Some monitors also have ports. Wireless devices Cotlnt!ct through
infrared or radio waves.
Page 2 of 10
LESSON 2
Modl-43
Ports and Connectors
A port, also c;:.lIed a jack, is an interface 10 which a per iphcml d evice allachcs 10
or communicates with the system unit. Older peripheral device.. usc seri al and
parnllcl ports to connect to the computer. Se rial devices transmit data one bit at a
lime. lJ:w.!l1e1 devices transfer eight bi ls at a lime. A b it is represented by a 0 Of I .
Typically, eig ht bits make O [)C byte. Most computers traditionally have al Jelisl one
pamUci pori and one serial porI. In older compUlers. you willlikcly find a printer
connected to 01 parallel port and perhaps a mOllse connected loa scri:ll port. A modem
is:1device Ihal allows one computer to talk to anothe r.
The Ull il,trsai Serial n its (US8) port can connect up [0 127 differenl peripherals with:1 single cOllnector and supports data trans fe r rates of 1I1) to 200 million bits
per second (Mbps) . USB replaces the standard serial and pamllcl ports on newer
compute rs. US B 2.0 is a recent and more advanced version of USB techno logy, with
speeds 40 times fll ster than that of its predecessors. Today 's personal computers typically have four to eight USB ports either on the front or back of the system unit.
Using a duisy-chain arrangement or a USB bub, you can usc a ~i n gle USB port to
connecl up 10 127 peripheral devices. A US B hub is a device Ihm plugs inlo a USB
pon und contains multiple USB ports into which cablcs from USB devices elm be
plugged . US B also supports plug-and-play and hot plugging. Plllg-lIl1d-play refers
10 Ihe ability of a computer syslem to configure expansion boards .md olher devices
automatkillly. Hot plugging is the ability to add and remove devices to a computer
while the compu ter IS runnmg and tlave ttle operaung system automatic,llIy recogniz..: the change.
Another type o f external bus is Fire1t'ire. also known as IEEE 1394 and
IEEE I 394b. The IEEE 1394 bus standard supports data transfer nltes of up to
400 Mbps and can connect up to 63 extern.al devices: IEEE I 394b pro"idcs speeds
up 10 3200 Mbps . •' igu re 2- 18 shows an example of some of the more popular
Ir.tditionlll porlS and exa mples of FireWire and US B ports.
• VOCABULARY
poet
modem
Uni,·e.-sal Serial Bus (USH)
plug-and-play
.-ireWire
@
EXTRA FOR EXPERTS
USB 3.0 has recently been
released, and has ten times the
current bandwidth of USB 2.0.
Transfer ra tes are approximately
4.8 Gb itslsec (Gigabits per second) and should be a..,ailable in
commercial products in 2009.
FireWire port
USB potts
ports
FIGURE 2-18
Traditiona l, USB, and FireWire ports
Page 3 of 10
MDdl -44
MODULE 1
Computing Fundamental s
In addition to the preceding ports. you mi ght find three additional specialpurpose ports on various computin g devices. These special-purpose po rls arc:
•
SCSI: An abbreviation for Small Computer Syslcmlntcrface, SCS I (pronounced
skuzzy) is a standard interface for connecti ng peripherals such as disk drives
printers.
;:lIld
•
IrDA: A wireless standard that allows data to be transferred between devices
usi ng infmred light instead of cables is called lrDA. Both thc computer and thc
device must have an lfDA port, and thc IfDA (XJrt 011 the device must aLign with
the lrDA port on the computer.
•
Bluetoorh: B[uclooth uses radio waves ;:md provides wireless short-range
communications of data and voice between both mobile and stationary devices.
This technology does not require alignment: it is an alternative to IrDA. See
l ' igu re 2- 10
FIGURE 2- 19
• VOCABULARY
e xpa nsion slul
Bluetooth device
Erpa ".~ioll slots are openings on the motherboard where :.111 expansion board .
also called an ad~pter card. elill be inserted. Expansion boards e nhance functions of
a component of the system unit lmd/or provide connections through a pon or other
connectors to peripheral devices. Exp.ansion boards are also called expansion cards,
add-ins. and add-ons. See Figu re 2-20.
Page 4 of 10
LESSON 2
Input, Output, and P,oce" ing
Modl-45
Expansion ---Il;"
card
Expansion
slots
FIGURE 2-20
Expansion slots and card
Tr.tditio nally. rorts have been located on Ihe back of the system unie. With the
introduction of portable devices, such as digital camcr.lS and pocket pes, mnny
newer computers also indude pOrlS on the front of the sys tem unit. This provides fo r
easier :.ccess.
Hardware Installation
For most hardw:tre devices to work. they need a set of instruc tions Ihal communic,ltes with thc computer's operating system. This ~ ct of instructio ns is called u
driver. In many instances. the operating system includes drivers for the more popular
pe rip heral devices LInd performs tin automatic plug-and-play imnallutio n fOf newly
connected devices.
If thc opcrUling system docs not contain a driver for the hardware, the dri ver
needs 10 be inslalled manually. Usually, the software is included wilh the hurdwarc
device. If an installation di sk is nOi available, Ihe manuf(lourer"s Web site gcncmll y
prGvides a downloadable fil e.
Computer Performance Factors
A variety of factors can affect a computer's pcrfomlance . In Lesson I , you leamed
aboUllhe celllmi processor. compuler me mory. and inpulfootplll devices. 11lcsc Ih.rce
components. plus video capability and disk organization. affetl lhe speed at whjch
1· 1.1.9
the computer performs.
The followin g list provides an overview of these various devices and disc usses
how more than one component can slow down or speed up computer performance.
I. Micro/Jroce.ssor: The architecture of the central processor is the most important
processing clemen!. CPUs arc classified by generations. The higher the
gcner:ltion. the faster and better the processing speed. Some processors support
Page 5 of 10
MDdl -46
MODULE 1
parallel processing. With this type of processing. while one instruction is being
executed . the next instruction is fetched from memory and decoded. Th u s., thc
faster the processor, the more instructions per second it can process.
2.
R illlt/Oll! access memol)' (RAM ): The amount of RAM also helps to increase
the processing cycle and to enhance the computer's performance. When the
memory capacity is reached , the CP U stores data o n the hard drive. This slows
down the processi ng cycle because it takes longer for the CPU to read from a
hard drive compared to reading from RAM.
3. Hard disk: The size and speed of the hard drive also affects a computer' s
performance. The bigger and faster the hard drive. the faster the data is
processed. In addition, how the disk is organized affects computer perfonn;mce.
If a hard disk contai ns many unneeded and outdated files , it takes longer for the
computer to find the information it needs.
4.
Video: The video device that is connected to the computer c a.n enhance or slow
down the comput er's perfannance. Having adequate video memory far the
video card allows the processor to petform 10 its full potential.
Windows Vista provides several options to dctennine what hardware yo u have in
your computer system. In Step-by-Step 2.1 . you learn how to view th is infonnatioll.
When you view this information. most likely you will see abbreviations suc h as MB or
GB. which are units for measuring bytes. Bits and bytes were discussed in Lesson I.
Step-by-Step 2_1
1. Click the Start button
on the taskba r, and t hen click Computer. The
Computer window appears, as shown in Figure 2- 21.
FIGURE 2- 21
Computer window
2. Cli c k System praperties on the menu bar. The System screen is
displayed (see Figure 2- 22 ). Most likely, your System screen will
display different system information than that in Figure 2- 22.
Page 6 of 10
LESSON 2
Modl-47
FIGURE 2- 22
----.,....._c ___ . __
--------- 1!lI - --
System window
System
window
--
<
---""'--. . . . .
<----
~-
~-~-
Change
" - setti ngs link
~-
--
---
3. What Microsoft Windows edit ion is listed for your computer? What processor does your computer contain? How much Memory (RAM) is in you r
computer? What description and name are assigned to your computer?
4 . Click the Change settings l ink. If a User Account Control dialog boK is
displayed, click the Continue button. The System Properties dialog box
is displayed (see Figure 2- 23 ),
FIGURE 2-23
Tabs
Wndow,
on the
u, e ~
nd"""'"
the I_
g " ",motion 10 ;;,.ntiy Y'Y
For ",""",,": '1(Jcn.., ~ .. " C<
Coovi"'''
FUloo:rp.te rnarne:
O\OIUl
W'<MI<~ -..>:
WORKGR OUP
System Properties
dialog box
~ er
''''.9'.
OK button
Conce!
~
Page 7 of 10
MDdl -48
MODULE 1
5 . Click each of the tabs in the dia l og box and read the information con-
tained on each tab . If directed by your instructor, use Notepad or your
word-processing program and write an overv iew of the features contained wit hin the System Properties dia log box.
6. Click the OK button to close t he System Properties dialog box, and then
close the System window.
ETHICS IN TECHNOLOGY
''''''
~ ~ ~
Computer Viruses
The word virus can put fear into anyone who uses the Internet or exchanges disks. How can such a small
.....ord cause such fear? It is because a virus can cause tremendous damage to your computer files!
A virus is a computer program that is written intentionally to attach itself to other programs or disk boot
sectors and dup licates itself whenever those programs are executed or the i nfected disks are accessed . A
virus can wipe out all of t he files on your computer.
Viruses can sit on your computer for weeks or months and not cause any damage unti l a predetermined
date or time code is activated . Not all viruses cause damage . Some are just pranks; maybe your mon itor will
display some sil ly message . Viruses are created by persons who are impressed with the power they possess
because of their expertise in the area of computers; sometimes they create them just for fun . To protect your
c·:lmputer from virus damage, insta ll an antivirus software program on your computer and keep it running at
all times so that it can continuously scan for viruses.
SUMMARY
In this lesson, you Il'arnro:
•
Input devices enable you to inpul data and commands into the
computer. The most C0l111110n input devices arc the keyboard
and mouse.
•
Other type... of input devices include the trackball. joystick.
wheel. poillling stick. g raphics tablet. tOlleh display screen.
stylus, voice recognition dcyices, louchpad, scanner, digital
camera. video input. and biometric input.
•
Monitors and printers arc examples of output devices. Monitors
produce soft copy. Primers arc used to produce a paper or hard
copy of the processed result.
•
Criteria for selecting a printer include speed. print quality.
and cos!.
•
[nput and output dcvices must be connected to the computer.
Somc input and output devices communicate with the com·
puter through a physical mnnectioll. Wireless devices communicate with the computer through infrared or radio waves.
•
Peripheral devices arc connected 10 [he computer through
serial, parallel. and Universal Serial Bus (USB) pGm. USB is a
newer standard expected 10 replace serial and parallel ports.
•
Firc\Vire is a type of external bus thm can amncet up to
63 external dc:vices.
•
SCSI. IrDA, and Bluelootll arc s.pecial-purpos.e ports.
•
A computer·s pc:rformance is affected by the speed of the pro·
cessor, the amount of RAM, hard disk size and sp'~ed , capabil.
ity of monitor. and disk organization.
Page 8 of 10
LESSON 2
•
VOCABULARY REVIEW
Detin~
th e- following t('rms:
audio inplII
biometrics
d igital camcra
cxpansion slot
FireWirc
inkjct printer
input
•
keyboard
laser prinler
modcm
monitor
mouse
output
plug -and-play
Modl-49
pointing device
port
printer
scanner
trackball
Universal Scrial Bus (US B)
REVIEW QUESTIONS
TRUEI FALSE
Cirde T if the statement is true- or F irthe state-ment is false_
T
F
1.
Vidco input is thc proccss of capturing full -motion images with a vidco camcra.
T
F
2.
Input and outpul device~ perfonn the sallie funelion.
T
F
3.
A data projector is a type of specializcd output device that projects the computer image onto a screen.
u~ually
duri llg a
presentation.
T
F
4.
In put and output deviccs can stand alone-they do not nced to be connected to the computer.
T
F
5.
An optical mousc uscs a laser to detcct!.hc mouse's movcment.
MULTIPLE CHOICE
Select the best response for the following statements.
I. Wh ich of the fol lowing is 110/ considered an input device?
C. mouse
B.
scanner
D. monitor
2. \¥hich onc of the follow ing is a type of scanner that con"erL~ graphics into an eleetronic form?
A.
image scanner
C. bar code scanner
B.
magnetic scanner
D. OCR scanner
3. Plug-and-play refers to a computer's abili ty to _ _ _ _ _ _ __
A.
connect mu lti ple USB devices
B.
c()nfi gure hordwnrt: devices uutolllu ti cally
C.
c()t1Imunicatc with lhc system unit
D.
talk to another computer
produce an image by manipulating light within a layer of liquid crystal cells.
4.
A.
Gas plasma mon itors
C. CRT monitors
B.
LCD panels
D. Scanners
5. \¥hich of thc following is a biometri c identification scunn ing technjque?
A.
fingerprint
C. V01ee
B.
face
D. all of the above
Page 9 of 10
MODULE 1
Modi -50
FILL IN THE BLANK
Complete the following senll'nces by wrilin g t he
I. A(n) _ _ _ _ _ _ _ _
i~
cor~ct
word or words in the blanks provided.
the most widely used device for entering data into the computer.
2. _ _ _ _ _ _ _ _ is data or instructions entered into the computer.
3. The _ _ _ _ _ _ _ _ port can conneCI up to 127 different peripherals with a si n gle con nector.
4. To improve perform ance dramatically. increase the amount of _ _ _ _ _ _ _ _ on your COllllJutcr.
S. A(n) _ _ _ _ _ _ _ _ is a small. battery-powered printer. primarily used to print from a notebook computer.
•
PROJECTS
PROJECT 2- 1
PROJECT 2- 2
Gmai! is a frcc Web mail service provided through Goog lc. Complete
the following sleps to create an account.
Biometric tech nology is lhe autom[lted method of recognizing a
person based on a physiological or behavioral characteristic. Usc
lhe Internet and other sources to research this topic.
I. Opcn your browser and go to IlIIp:llmllil.google.comlllwifl
heip/open./wlll.
2. W hen the W elcome
to
Gmu; ] screen is displayed, read the
information prov ided on the page.
accounl link.
TI1Cil
clic k thc Create an
3. Type your first and las t name and desired 10Bin name. C lick the
check availability button to verify that thc name is availab lc.
I. Use your favorite search engine to search for Web pages
discuss ing b iometric technology.
2.
Ba~ed on your findings, creale a d(K; ument listing the pros and
cons of biometric tech nology. Include your personal opi n ion
about this topic.
3. Submit the doc ument to your instructor as rcquested.
4. When selceting a password, Google assists w ith a password
stre ngth level- poor, fai r, and strong. Your goal is \0 create a
strong password. It must be a minimum of eight character.;..
Be sure to wri te down your password or send the password to
yourself in an e-mail.
PROJECT 2- 3
Preparc a wriltc n report on input devices.
I . Select at least fivc input dcviccs discussed in Ihis lesson.
S. If you arc using a schoo! computer or a computer other than
your own . do not se!eet lhe " Remember me on Ihis computer"
or the " Enable Web History" check boxes.
2. Create a document for the report. Include a table i[1 your report
6. Select a Security Question that you arc sure to remember.
E- maillhe answer 10 yourself.
3. Submit the document to your instruclOr as rcquested.
7. If you have anothe r e-mai! address. you can emer it illlo thc
Secondary c-mai! text box. However, this is nOl necessary or
required.
8. For Word Vcrifkation. type the charactcrs displayed on the form.
9. Read the Terms of Service. and then click the I accept. C reate
my account bullon.
10. When an Introduction to Gmail page is dis played, read the
information on the page and the n click Sho w me my account.
Sign in to your account using your user name and password.
II. Click the Compost' Mail link and send a message to your
instructor and/or another classmate. List three facts in the
message thal rdate to the topics presented in this lesson. Print
a copy of your message and sub mit it to your illslructor.
listing eac h input device. describing how it could be used. and
explaining the dcvice's advantages and disadvantages.
I:lI TEAMWORK PROJECT
This exercise is a stu dent role-playing activ it y. Students arc given
a specific task and a set of rules. They then role-play paris of a
computer to accompl ish thc task. Studcnt roles incl ude a processor,
main memory. 5torage dcvice.~. ilnd input/outpul devic(;~. Followi ng
are some of the task examples: (a) inpulling pictures from a digital camcra, modifying and viewing the !JictUI·CS . and outpUlling and
printing the pictures; (b) using word-proccssing software toereate a
report on a specified schoo! lopic. addi ng pictures \0 the repol1. and
then pri ming copies for all students in the class; (c) students usc a
5prcadshcct program to create a worksheet and chart and then print
copies for al! students in the class: Cd) students use a presentation
program such as PowerPoilit and create a prescntation with tex!.
images. and video: they display the prcscntation to the class.
f'Or additional infonnation, sce hltp:/Illwil.goog le.com/supporlf.
Page 10 of 10
LESSON 2
•
CRITICAL THINKING
You wan! to leam more about how the computer processes data
and the factors that innucncc the processing speed. Your ins tructor
thinks this is a great idea and asks you to prepare a report on what
•
Modl-51
factors produce the Dcsl overall processing system. Prepare !I report
lis ting the devices you would sekct to produce the best all -around
process ing system .
ONLINE DISCOVERY
Google has a feature thai focuses solely on blog searching. This featurc. called Blog Search. is located at www.google.comlblogsearch.
Access this Web site and then search for increase COmpl/fer speed.
Wri te a one-page report on what you learned.
Page 1 of 10
Page 2 of 10

Computer Literacy BASICS: A Comprehensive Guide to IC3, 3rd

Transcription

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