Fundamental of Computers Manual

8/13/2019 Fundamental of Computers Manual

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ELGON VIEW COLLEGE

The Computer &

Personal Computer

Hardware Support

Notes

Lecturer : Mr Nyandika

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1 COMPUTER LITERACY

The vocabulary of computin i! all aroun" you# $efore the a"vent of computer!%memory &a! the mental ability to recall previou! e'perience!( !torae &a! an area&here you )ept out*of*!ea!on clothin( an" communication &a! the act ofe'chanin opinion! an" information throuh &ritin% !pea)in% or !in!# Into"ay+! &orl"% the!e &or"! an" countle!! other! have ta)en on ne& meanin! a!part of the common terminoloy u!e" to "e!cribe computer! an" their u!e#

,hen you hear the &or" computer% initially you may thin) of tho!e foun" in the&or)place * the computer! u!e" to create bu!ine!! letter!% memo!% an" othercorre!pon"ence( calculate payroll( trac) inventory( or enerate invoice!# In thecour!e of a "ay or &ee)% ho&ever% you encounter many other computer!# Yourhome% for in!tance% may contain a myria" of electronic "evice!% !uch a! cor"le!!telephone!% -CR!% han"hel" vi"eo ame!% camera!% an" !tereo !y!tem!% thatinclu"e !mall computer!#

Computer! help you &ith your ban)in in the form of automatic teller machine!.ATM!/ u!e" to "epo!it or &ith"ra& fun"!# ,hen you buy rocerie!% a computertrac)! your purcha!e! an" calculate! the amount of money you o&e( an"

!ometime! enerate! coupon! cu!tomi0e" to your buyin pattern!#Even your car i! euippe" &ith computer! that operate the electrical !y!tem%control the temperature% an" run !ophi!ticate" antitheft "evice!#

Computer! are valuable tool!# A! technoloy a"vance! an" computer! e'ten" intoevery facet of "aily livin% it i! e!!ential you ain !ome level of computer literacy.To be !ucce!!ful in to"ay+! &orl"% you mu!t have a )no&le"e an" un"er!tan"inof computer! an" their u!e!#

1#2# ,3AT I4 A COMPUTER A56 ,3AT 6OE4 IT 6O7

A computer i! an electronic machine% operatin un"er the control of in!truction!!tore" in it! o&n memory% that can accept "ata .input/% manipulate the "ataaccor"in to !pecifie" rule! .proce!!/% pro"uce re!ult! .output/% an" !tore there!ult! for future u!e#

Datai! a collection of un*orani0e" fact!% &hich can inclu"e &or"!% number!#imae!% an" !oun"!# Computer! manipulate an" proce!! "ata to createinformation#

Informationi! "ata that i! orani0e"% ha! meanin% an" i! u!eful# E'ample! arereport!% ne&!letter!% a receipt% a picture% an invoice% or a chec)# 6ata i! proce!!e"an" manipulate" to create a chec)#

6ata entere" into a computer i! calle" input# The proce!!e" re!ult! are calle"output# Thu!% a computer proce!!e! input to create output# A computer al!o canhol" "ata an" information for future u!e in an area calle" !torae# Thi! cycle ofinput% proce!!% output% an" !torae i! calle" the information processing cycle#

A per!on that communicate! &ith a computer or u!e! the information it enerate!i! calle" a u!er# The electric% electronic% an" mechanical euipment that ma)e! upa computer i! calle" hardware# Software i! the !erie! of in!truction that tell! thehar"&are ho& to perform ta!)!# ,ithout !oft&are% har"&are i! u!ele!!( har"&are#

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1#8 T3E COMPO5E5T4 O9 A COMPUTER

A computer con!i!t! of a variety of har"&are component! that &or) toether &ith!oft&are to perform calculation!% orani0e "ata% an" communicate &ith othercomputer!#

The!e har"&are component! inclu"e input "evice!% output "evice!% a !y!tem unit%!torae "evice!% an" communication! "evice!# 9iure 1*1 !ho&! !ome common

computer har"&are component!#

1.3.1 Input Devices

An input "evice allo&! a u!er to enter "ata an" comman"! into thememory of a computer# 9our commonly u!e" input "evice! are the)eyboar"% the mou!e% a microphone% an" a PC camera#

A computer )eyboar" contain! )ey! that allo& you to type letter! of thealphabet% number!% !pace!% punctuation mar)!% an" other !ymbol!# Acomputer )eyboar" al!o contain! !pecial )ey! that allo& you to perform

!pecific function! on the computer#

A mou!e i! a !mall han"hel" "evice that contain! at lea!t one button# Themou!e control! the movement of a !ymbol on the !creen calle" a pointer#9or e'ample% movin the mou!e acro!! a flat !urface allo&! you to movethe pointer on the !creen# You al!o can ma)e choice! an" initiateproce!!in on the computer by u!in a mou!e#

A microphone allo&! you to !pea) to the computer in or"er to enter "ataan" control the action! of the computer# A PC camera allo&! other! to !eeyou &hile communicatin &ith you% a! &ell a! allo&in you to e"it vi"eo!%create a movie% an" ta)e "iital photoraph!#

1.3.2. Output Devices

An output "evice i! u!e" to convey the information enerate" by acomputer to a u!er# Three commonly u!e" output "evice! are a printer% amonitor% an" !pea)er!#

A printer pro"uce! te't an" raphic!% !uch a! photoraph!% on paper orother har"copy me"ium# A monitor% &hich loo)! li)e a televi!ion !creen% i!u!e" to "i!play te't an" raphic!# 4pea)er! allo& you to hear mu!ic% voice%an" other !oun"! enerate" by the computer#

1.3.3 System Unit

The !y!tem unit i! a bo'*li)e ca!e ma"e from metal or pla!tic that hou!e!the computer electronic circuitry# The circuitry in the !y!tem unit u!uallyi! part of or i! connecte" to a circuit boar" calle" the motherboar"#

T&o main component! on the motherboar" are the central proce!!in unit.CPU/ an" memory# The central proce!!in unit .CPU/% al!o calle" aproce!!or% i! the electronic "evice that interpret! an" carrie! out thein!truction! that operate the computer#

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compact "i!c i! aD$D-!"# &hich ha! tremen"ou! !torae capacitie! *enouh for a full*lenth movie# To u!e a 6-6*ROM% you nee" a 6-6*ROM "rive#

1.3.% Communications Devices

Communication! "evice! enable computer u!er! to communicate an" toe'chane item! !uch a! "ata% in!truction!% an" information &ith another

computer# Communication! "evice! tran!mit the!e item! over tran!mi!!ionme"ia% !uch a! cable!% telephone line!% or other mean!% u!e" to e!tabli!h aconnection bet&een t&o computer!# A mo"em i! a communication! "evicethat enable! computer! to communicate via telephone line! or othermean!# Althouh mo"ern! are available a! both e'ternal an" internal"evice!% mo!t are internal( that i!% containe" &ithin the !y!tem unit#

1#?# ,hy I! a Computer a Po&erful Tool7

A computer+! po&er i! "erive" from it! capability of performin the information proce!!in cycle

operation! &ith !pee"% reliability% an" accuracy( it! capacity to !tore hue amount! of "ata%

in!truction!% an" information( an" it! ability to communicate &ith other computer!#

1.4.1 Speed

In!i"e the !y!tem unit% operation! occur throuh electronic circuit!# ,hen "ata%

in!truction!% an" information flo& alon the!e circuit!% they travel at clo!e to the !pee" of

liht# Thi! allo&! billion! of operation! to be carrie" out in a !inle !econ"#

1.4.& elia'ility

The electronic component! in mo"ern computer! are "epen"able becau!e they have a lo&

failure rate# The hih reliability of component! enable! the computer to pro"uce

con!i!tent re!ult!#

1.4.3 (ccuracy

Computer! can proce!! lare amount! of "ata an" enerate error*free re!ult!% provi"e" the

"ata i! entere" correctly# If inaccurate "ata i! entere"% the re!ultin output &ill be

incorrect# Thi! computin principle * )no&n a! arbae in% arbae out .@I@O/% point out

that the accuracy of a computer+! output "epen"! on the accuracy of the input#

1.4.4 Storage

Many computer! can !tore enormou! amount! of "ata an" ma)e thi! "ata available for

proce!!in any time it i! nee"e"# U!in current !torae "evice!% the "ata can betran!ferre" uic)ly from !torae to memory% proce!!e"% an" then !tore" aain for future

u!e#

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1.4.% Communications

Mo!t computer! to"ay have the capability of communicatin &ith othercomputer!# Computer! &ith thi! capability can !hare any+ of the fourinformation proce!!in cycle operation! * input% proce!!% output% an"!torae * &ith another computer# 9or e'ample% t&o computer! connecte"by a communication! "evice !uch a! a mo"em can !hare !tore" "ata%in!truction!% an" information# ,hen t&o or more computer! are connecte"toether via communication! me"ia an" "evice!% they compri!e a net&or)#

The mo!t &i"ely )no&n net&or) i! the Internet# a &orl"&i"e collection ofnet&or)! that lin)! toether million! of bu!ine!!e!% overnmentin!tallation!% e"ucational in!titution!% an" in"ivi"ual!#

1## COMPUTER 4O9T,ARE

4oft&are% al!o calle" a computer proram or !imply a proram% i! a !erie! ofin!truction! that tell! the har"&are of a computer &hat to "o# 9or e'ample% !omein!truction! "irect the computer to allo& you to input "ata from the )eyboar" an"!tore it in memory# Other in!truction! cau!e "ata !tore" in memory to be u!e" incalculation! !uch a! a""in a !erie! of number! to obtain a total# 4omein!truction! compare t&o value! !tore" in memory an" "irect the computer to

perform alternative operation! ba!e" on the re!ult! of the compari!on( an" !omein!truction! "irect the computer to print a report% "i!play information on themonitor% "ra& a color raph on the monitor% or !tore information on a "i!)#

$efore a computer can perform% or e'ecute% a proram% the in!truction! in theproram mu!t be place"% or loa"e"% into the memory of the computer# U!ually%they are loa"e" into memory from !torae# 9or e'ample% a proram miht beloa"e" from the har" "i!) of a computer into memory for e'ecution#

,hen you purcha!e a proram% !uch a! one that contain! leal "ocument!% you&ill receive one or more floppy "i!)!% one or more C6*ROM!% or a !inle 6-6*ROM on &hich the !oft&are i! !tore"# To u!e thi! !oft&are% you often mu!t in!tallthe !oft&are on the computer+! har" "i!)#

4ometime!% a proram can be loa"e" in memory "irectly from a floppy "i!)% C6*ROM% or 6-6*ROM !o you "o not have to in!tall it on a har" "i!) fir!t# ,hencomputer# it u!ually ha! !ome !oft&are alrea"y in!talle" on it! har" "i!)# Thu!%you can u!e the computer a! !oon a! you receive it#

4oft&are i! the )ey to pro"uctive u!e of computer!# ,ith the correct !oft&are% acomputer can become a valuable tool# 4oft&are can be cateori0e" into t&o type!B!y!tem !oft&are an" application !oft&are# The follo&in !ection! "e!cribe the!ecateorie! of !oft&are#

1.%.1 System Software

4y!tem !oft&are% &hich con!i!t! of proram! that control the operation! ofthe computer an" it! "evice!% !erve! a! the interface bet&een a u!er an"the computer+! har"&are# T&o type! of !y!tem !oft&are are the operatin!y!tem an" utility proram!#

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!)*(+I, SS+*"

The operatin !y!tem contain! in!truction! that coor"inate all ofthe activitie! of har"&are "evice!# The operatin !y!tem al!ocontain! in!truction! that allo& you to run application !oft&are#Micro!oft ,in"o&! i! the name of a popular operatin !y!tem thati! u!e" on many of to"ay+! computer!#

,hen you !tart a computer% the operatin !y!tem i! loa"e"% orcopie"% into memory from the computer+! har" "i!)# It remain! inmemory &hile the computer i! runnin an" allo&! you tocommunicate &ith the computer an" other !oft&are#

U+I/I+ )!("S

A utility proram i! a type of !y!tem !oft&are that perform! a!pecific ta!)# u!ually relate" to manain a computer# it! "evice!%or it! proram!# An e'ample of a utility proram i! an unin!taller%&hich remove! a proram that ha! been in!talle" on a computer#Mo!t operatin !y!tem! inclu"e !everal utility proram! for

manain "i!) "rive!% printer!% an" other "evice!# You al!o can buy!tan"*alone utility proram! to perform a""itional computermanaement function!#

US* I,+*0(C*

All !oft&are ha! a u!er interface that i! the part of the !oft&are&ith &hich you interact# The u!er interface control! ho& "ata an"in!truction! are entere" an" ho& information i! pre!ente" on the!creen# Many of to"ay+! !oft&are proram! have a raphical u!erinterface% or @UI .pronounce" ooey/% &hich allo&! you to

interact &ith the !oft&are u!in vi!ual imae! !uch a! icon!# Anicon i! a !mall imae thatrepre!ent! a proram% an in!truction% or!ome other ob>ect#

1.%.& (pplication Software

Application !oft&are con!i!t! of proram! "e!ine" to perform !pecificta!)! for u!er!# Popular application !oft&are inclu"e! &or" proce!!in!oft&are% !prea"!heet !oft&are% "ataba!e !oft&are% an" pre!entationraphic! !oft&are memo!# 4prea"!heet !oft&are allo&! you to calculatenumber! arrane" in ro&! an" column! an" often i! u!e" for bu"etin%foreca!tin% an" other financial ta!)!# 6ataba!e !oft&are i! u!e" to !tore"ata in an orani0e" fa!hion% a! &ell a! to retrieve% manipulate% an" "i!playthat "ata in a meaninful form# Pre!entation raphic! !oft&are allo&! youto create "ocument! calle" !li"e! that are u!e" in ma)in pre!entation!#The!e four application! often are !ol" toether a! a !inle unit% calle" a!uite% in &hich in"ivi"ual application! are pac)ae" in the !ame bo' an"!ol" for a price that i! !inificantly le!! than buyin the application!in"ivi"ually#

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Many other type! of application !oft&are e'i!t% thu! enablin u!er! toperform a variety of ta!)!# 4ome &i"ely u!e" !oft&are application!inclu"eB reference e"ucation% an" entertainment( "e!)top publi!hin( photoan" vi"eo e"itinB multime"ia authorinB net&or)% communication!%electronic mail% an" ,eb bro&!er!( accountinB pro>ect manaement( an"per!onal information manaement#

Application !oft&are i! available a! pac)ae" !oft&are% cu!tom !oft&are% !hare&are%

free&are% an" public*"omain !oft&are#

)(C(*D S!0+2(*

Pac)ae" !oft&are i! "e!ine" to meet the nee"! of a &i"e varietyof u!er!% not >u!t a !inle u!er or company# Pac)ae" !oft&are!ometime! i! calle" commercial off*the*!helf !oft&are becau!e youcan purcha!e the!e proram! off the !helf from !oft&are ven"or! or!tore! that !ell computer pro"uct!# You al!o can purcha!e pac)ae"!oft&are on the Internet# 4ome companie! to"ay offer pro"uct! onthe Internet( that i!% in!tea" of in!tallin the !oft&are onto yourcomputer% you run the proram! on the Internet#

CUS+!" S!0+2(*

4ometime! a u!er or orani0ation &ith uniue !oft&arereuirement! cannot fin" pac)ae" !oft&are that meet! all of it!nee"!# In thi! ca!e% the u!er or orani0ation can u!e cu!tom!oft&are% &hich i! a proram or proram! "evelope" at a u!er+!reue!t to perform !pecific function!#

S(*2(*

4hare&are i! !oft&are that i! "i!tribute" free for a trial perio"# Ifyou &ant to u!e a !hare&are proram beyon" that perio" of time%you are e'pecte" to !en" a payment to the per!on or company that

"evelope" the proram# Upon !en"in thi! !mall fee% the "eveloperrei!ter! you to receive !ervice a!!i!tance an" up"ate!#

0** 2(* (,D )U/IC-D!"(I, S!0+2(*

9ree&are i! !oft&are that i! provi"e" at no co!t to a u!er by anin"ivi"ual or company# Althouh free% free&are i! copyrihte"%meanin you cannot re!ell it a! your o&n# Public*"omain !oft&arei! free !oft&are that ha! been "onate" for public u!e an" ha! nocopyriht re!triction!#

E'ample! of !hare&are% free&are% an" public*"omain !oft&areinclu"e utility proram!% raphic! proram!% an" ame!#

Thou!an"! of the!e proram! are available on the Internet( youal!o can obtain copie! of the proram from the "eveloper% a co*&or)er% or a frien"#

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1# 5ET,ORD4 A56 T3E I5TER5ET

A net&or) i! a collection of computer! an" "evice! connecte" toether viacommunication! me"ia an" "evice! !uch a! cable! telephone line!% mo"em!% orother mean!# 4ometime! a net&or) i! &irele!!( that i!% u!e! no phy!ical line! or&ire!# ,hen your computer i! connecte" to a Computer! are net&or)e" toether!o u!er! can !hare re!ource!% !uch a! har"&are "evice!% !oft&are proram!% "ata%an" information# 4harin re!ource! !ave! time an" money# 9or e'ample% in!tea"of purcha!in one printer for every computer in a company or in a home% you can

connect a !inle printer an" all computer! via a net&or) .9iure 1*2/( the net&or)enable! all of the computer! to acce!! the !ame printer#

Mo!t bu!ine!! computer! are net&or)e" toether# The!e net&or)! can berelatively !mall or uite e'ten!ive# A net&or) that connect! computer! in a limite"eoraphic area% !uch a! a !chool computer laboratory% office% or roup ofbuil"in!% i! calle" a local area net&or) .LA5/# A net&or) that cover! a lareeoraphical area% !uch a! one that connect! the "i!trict office! of a nationalcorporation% i! calle" a &i"e area net&or) .,A5/.

The &orl"+! lare!t net&or) i!the Internet% &hich i! a &orl"&i"e collection ofnet&or)! that lin)! toether million! of computer! by mean! of mo"em!%telephone line!% &irele!! technoloy% an" other communication! "evice! an"me"ia# ,ith an abun"ance of re!ource! an" "ata acce!!ible via the Internet% morethan 1&% million u!er! aroun" the &orl" are ma)in u!e of the Internet for avariety of rea!on!% !ome of &hich inclu"e the follo&inB

4en"in me!!ae! to other connecte" u!er! .e*mail/ Acce!!in a &ealth of information% !uch a! ne&!% map!% airline !che"ule!%

an" !toc) mar)et "ata 4hoppin for oo"! an" !ervice! Meetin or conver!in &ith people aroun" the &orl" Acce!!in !ource! of entertainment an" lei!ure% !uch a! online ame!%

maa0ine!% an" vacation plannin ui"e!

One of the more popular !ement! of the Internet i! the ,orl" ,i"e ,eb% al!ocalle" the ,eb% &hich contain! billion! of "ocument! calle" ,eb pae!# A ,ebpae i! a "ocument that contain! te't% raphic!% !oun"% or vi"eo% an" ha! built*inconnection!% or lin)!% to other ,eb "ocument!# ,eb pae! are !tore" oncomputer! throuhout the &orl"# A ,eb !ite i! a relate" collection of ,eb pae!#You acce!! an" vie& ,eb pae! u!in a !oft&are proram calle" a ,eb bro&!er#The t&o mo!t popular ,eb bro&!er! are Micro!oft Internet E'plorer an"5et!cape 5aviator#

1#< CATE@ORIE4 O9 COMPUTER4

The four ma>or cateorie! of computer! are per!onal computer!% minicomputer!%mainframe computer!% an" !upercomputer!# The!e cateorie! are ba!e" on the"ifference! in the !i0e% !pee"% proce!!in capabilitie!% an" price of computer!# 6ueto rapi"ly chanin technoloy% the cateorie! cannot be "efine" preci!ely# 9ore'ample% the !pee" u!e" to "efine a mainframe to"ay may be u!e" to "efine aminicomputer ne't year# 4ome characteri!tic! may overlap cateorie!# 4till% theyfreuently are u!e" an" !houl" be un"er!too"#

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1.5.4 SU)*C!")U+*S

A !uper*computer i! the fa!te!t% mo!t po&erful computer * an" the mo!te'pen!ive# Capable of proce!!in more than ? billion in!truction! in a!inle !econ"% !upercomputer! are u!e" for application! reuirincomple'% !ophi!ticate" mathematical calculation!# 9or e'ample% a!upercomputer &oul" be u!e" for &eather foreca!tin% nuclear eneryre!earch% an" petroleum e'ploration#

1# EFAMPLE4 O9 COMPUTER4 U4A@E

Every "ay% people "epen" on "ifferent type! of computer! for a variety of application!#

1.7.1 ome Users

3ome u!er! rely on their computer! for entertainment( communication!(re!earch an" e"ucation( ,eb acce!!( !hoppin( per!onal finance( an"pro"uctivity application! !uch a! &or" proce!!in an" !prea"!heet!#

1.7.& Small usiness Users

4mall bu!ine!! u!er! utili0e pro"uctivity !oft&are a! &ell a!communication! !oft&are% ,eb bro&!er!% e*mail% an" !peciali0e"!oft&are#

1.7.3 "o'ile Users

Mobile u!er! have laptop computer! !o they can &or) on the roa"# Theyoften u!e pre!entation !oft&are#

1.7.4 /arge usiness Users

Lare bu!ine!! u!er! u!e computer! to run their bu!ine!!e! by u!inpro"uctivity !oft&are% communication! !oft&are% automate" !y!tem! formo!t "epartment! in the company% an" lare net&or)!#

1.7.% )ower Users

Po&er u!er! reuire the capabilitie! of &or)!tation! or other po&erfulcomputer! to "e!in plan!% pro"uce publication!% create raphic art% an"&or) &ith multime"ia that inclu"e! te't% raphic!% !oun"% vi"eo% an" otherme"ia element!#

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1# The System Unt

The !y!tem unit i! a bo'*li)e ca!e hou!in the electronic component! of a computer that are u!e" toproce!! "ata# 4y!tem unit component! inclu"e the proce!!or% memory mo"ule% e'pan!ion car"!% an"port! an" connector!# Many component! re!i"e on a circuit boar" calle" the motherboar" or !y!temboar"# The motherboar" contain! "ifferent type! of chip!% or !mall piece! of !emicon"uctin material on&hich one or more interate" circuit! .IC/ are etche"# One of the more important chip! i! the central

proce!!in unit#

2#2 Central Proce!!in Unit

The central proce!!in unit .CPU/!!ometime! referre" to a! the proce!!or% interpret! an" carrie! out theba!ic in!truction! that operate a computer# That i!% mo!t of the "evice! connecte" to the computercommunicate &ith the CPU in or"er to carry out a ta!) .9iure 2*1/# The CPU contain! the control unitan" the arithmeticGloic unit#

&.&.1 +he Control Unit

The control unit% one component of the CPU% "irect! an" coor"inate! mo!t of the operation! inthe computer# 9or every in!truction% the control unit repeat! a !et of four ba!ic operation! calle"the machine cycle .9iure 2*2/" .1/fetchin the in!truction or "ata item from memory% .2/"eco"in the in!truction into comman"! the computer un"er!tan"!% .8/ e'ecutin the comman"!%an"% if nece!!ary% .?/ !torin!or &ritin% the re!ult to memory#

&.&.& (rithmetic8/ogic unit

The arithmeticGloic unit% another component of the CPU% perform! the arithmetic% compari!on%an" loical operation!# Arithmetic operation! inclu"e a""ition% !ubtraction% multiplication% an""ivi!ion# Compari!on operation! involve comparin one "ata item to another to "etermine if the

fir!t item i! reater than% eual to% or le!! than the other item# Loical operation! &or) &ithcon"ition! an" loical operator! !uch a! A56% OR% an" 5OT

&.&.3 egisters

The CPU u!e! temporary !torae location! calle" rei!ter!% to hol" "ata an" in!truction!# The function inclu"e!torin location of &here in!truction &a! fetche" !torin an in!truction &hile it i! bein "eco"e"% !torin "ata &hilethe ALU proce!!e! it% an" !torin the re!ult! of a calculation#

2#8# Microproce!!or! Compari!on

A per!onal computer+! CPU u!ually i! containe" on a !inle chip calle" a microproce!!or#Early Intel

microproce!!or! &ere i"entifie" &ith number!% but a more recent !erie! i! )no&n a! Pentium;proce!!or!# Intel proce!!or! &ith MMFHtechnoloy have a built*in !et of in!truction! that can be u!e"to manipulate an" proce!! multime"ia "ata more efficiently#

Intel*compatible microproce!!or! have the !ame internal "e!in a! Intel proce!!or! an" perform the!ame function!% but are ma"e by other companie! an" often are le!! e'pen!ive# The Motorolamicroproce!!or i! an alternative to the Intel*!tyle microproce!!or an" i! foun" in Apple Macinto!h an"Po&er Macinto!h !y!tem!# The Alpha microproce!!or% from 6iital Euipment Corporation% i! u!e"primarily in &or)!tation! an" hih*en" !erver!#


13/69

2#? Type! of Microproce!!or!

&.4.1 )arallel )rocessing

4ome computer! u!e more than one proce!!or to !pee" proce!!in time!# Dno&n a! parallelproce!!in% thi! metho" u!e multiple proce!!or! !imultaneou!ly to e'ecute a proram .9iure 2*

8/ Reuire! !pecial !oft&are "e!ine" to reconi0e ho& to "ivi"e up the problem an" then brinthe re!ult! bac) toether aain#

&.4.& Coprocessors

Another &ay to increa!e the performance of a computer i! throuh the u!e of a coproce!!or%&hich i! a !pecial proce!!or chip or circuit boar" "e!ine" to a!!i!t the proce!!or in performin!pecific ta!)!# U!er runnin enineerin% !cientific% or raphic! application!% for in!tance% &illnotice a "ramatic increa!e in !pee" &ith a floatin*point coproce!!or

2## 6ata Repre!entation

Mo!t computer! are "iital!meanin they un"er!tan" only t&o "i!crete !tate!B on an" off# The!e !tate!are repre!ente" u!in t&o "iit!% = i! u!e" to repre!ent the electronic !tate of off .ab!ence of anelectronic chare/ an" 1 i! u!e" to repre!ent the electronic !tate of on .pre!ence of an electronic chare/.9iure 2*?/#

Each on or off value i! calle" a bit .!hort for binary "iit/% &hich i! the !malle!t unit of "ata a computercan han"le# Eiht bit! roupe" toether a! a unit are calle" a byte# A byte can repre!ent 2 in"ivi"ualcharacter! inclu"in number!% letter! of the alphabet% punctuation mar)!% an" other character!#Combination! of =! an" 1! u!e" to repre!ent "ata are "efine" by pattern! calle" co"in !cheme!% the

number 1 i! repre!ente" a! ==11===1% the number a! ==11==1=% an" the capital letter M a! =1==11=1.9iure 2*/# Popular co"in !cheme! are A4CII! E$C6IC% an" Unico"e#

&.%.1 (SCII

The American 4tan"ar" Co"e for Information Interchane% i! the mo!t &i"ely u!e" co"in!y!tem to repre!ent "ata# I! u!e" on many per!onal computer! an" minicomputer!#

&.%.& *CDIC

The E'ten"e" $inary Co"e 6ecimal Interchane Co"e% i! u!e" primarily on mainframecomputer!

&.%.3 Unicode

I! co"in !cheme capable of repre!entin all the &orl"+! current lanuae!#


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Co"in !cheme! !uch a! A4CII ma)e it po!!ible for human! to interact &ith ! "iital computer thatreconi0e! only bit!# ,hen you pre!! a )ey on a )eyboar"% the electronic !inal i! converte" into abinary firm the computer un"er!tan"! an" i! !tore" in memory# That i!% every character i! converte" toit! corre!pon"in byte# The computer then proce!!e! that "ata in term! of byte!% &hich actually i! a!erie! of onGoff electrical !tate!# ,hen proce!!in i! fini!he"% the byte! are converte" bac) into number!%letter! of the alphabet% or !pecial character! to be "i!playe" on a !creen or be printe" .9iure 2*/# All ofthe!e conver!ion! ta)e place !o uic)ly that you "o not reali0e they are occurrin#

2## 6ifferent Type! of Memory

In the !y!tem unit% a computer+! memory !tore! "ata% in!truction!% an" information# Memory !tore! threeba!ic item!B The operatin !y!tem an" other !y!tem !oft&are that control the u!ae of the computereuipment( Application proram! "e!ine" to carry out a !pecific ta!) !uch a! &or" proce!!in( an" The"ata bein proce!!e" by application proram!# The number of byte! it can !tore mea!ure! memory !i0e a)ilobyte .D$/ i! appro'imately one thou!an" byte!% an" a meabyte .M$/i! appro'imately one millionbyte!#

&.9.1 ("

RAM .ran"om acce!! memory/ i! a memory chip that the proce!!or can rea" from an" &rite to#RAM i! volatile memory% meanin that it! content! are lo!t &hen the computer+! po&er i! turne"off#

.9iure 2*


15/69

Another type of nonvolatile memory i! calle" fla!h memory or fla!h ROM# Unli)e a PROM clip that can beproramme" only once% fla!h memory can be era!e" electronically an" reproramme"# 9la!h memory i! u!e" to!tore proram! on per!onal computer!% a! &ell a! cellular telephone!% printer!% "iital camera!% paer!% an" per!onal"iital a!!i!tant# 9la!h memory i! available in !i0e! ranin from 1 to ?= M$#

&.9.4 C"!S

Another of memory clip in the memory unit i! complementary metal*o'i"e !emicon"uctor.CMO4/# CMO4 memory i! nonvolatile memory u!e" to !tore confiuration information aboutthe computer% !uch a! the type of "i!) "rive!% )eyboar"% an" monitor( the current "ate an" time(an" other !tartup information nee"e" &hen the computer i! turne" off# CMO4 u!e battery po&erto retain information even &hen the po&er to the computer i! turn off# $attery*bac)e" CMO4memory thu! )eep! the calen"ar% "ate% an" time current even &hen the computer po&er i! off#Unli)e ROM% information !tore" in CMO4 memory can be chane"% !uch a! &hen you chanefrom !tan"ar" time to "ayliht !avin time#

&.9.% "emory (ccess +imes

The !pee" at &hich the proce!!or can acce!! "ata from memory "irectly affect! ho& fa!t the computer proce!! "ata#Thi! !pee" often i! "efine" a! acce!! time# Acce!! time i! mea!ure" in fraction! of a !econ"# 9or memory% acce!!

time! are mea!ure" in term! of a nano!econ"% &hich i! one billionth of a !econ"#2#oin a cable to a "evice#

&.7.1 ow Is a Serial )ort Different from a )arallel )ort:

Serial )ort

A !erial port i! one type! of interface u!e" to connect a "evice! to the !y!tem unit#$ecau!e a !erial port tran!mit! only one bit of "ata at a time% it u!ually i! u!e" to connect"evice! that "o not reuire fa!t "ata tran!mi!!ion rate!% !uch a! a mou!e% )eyboar"% ormo"em .fiure 2*


16/69

connector# Thi! parallel port can tran!fer eiht bit! of "ata !imultaneou!ly throuh eiht!eparate line! in a !inle cable .9iure 2*/# A parallel port !ometime! i! calle" aCentronic! interface% after the company that fir!t "efine" the !tan"ar" for communicationbet&een the !y!tem unit an" a printer# T&o ne&er type! of parallel port!% the EPP.Enhance" Parallel Port/ an" the ECP .E'ten"e" Capabilitie! Port/% u!e the !ameconnector! a! the Centronic! port% but are more than ten time! fa!ter#

#1 ,hat i! Input7

Input i! any "ata or in!truction! you enter into the memory of a computer# Once input i! in memory% theCPU can acce!! it an" proce!! the input into output# 9our type! of input are "ata% proram!% comman"!%an" u!er re!pon!e!B

6ata i! a collection of unorani0e" fact! that can inclu"e &or"!% number!% picture!% !oun"!% an"vi"eo!# A computer manipulate! an" proce!!e! "ata into information% &hich i! u!eful# Althouh

technically !pea)in% a !inle item of "ata !houl" be calle" a "atum% the term "ata commonly i! u!e"an" accepte" a! both the !inular an" plural form of the &or"#

A proram i! a !erie! of in!truction! that tell! a computer ho& to perform the ta!)! nece!!ary toproce!! "ata into information Proram! are )ept on !torae me"ia !uch a! a floppy "i!)% har" "i!)%C6*ROM% or 6-6*ROM# Proram! re!pon" to comman"! i!!ue" by a u!er#

A comman" i! an in!truction iven to a computer proram# Comman"! can be i!!ue" by typin)ey&or"! or pre!!in !pecial )ey! on the )eyboar"# A )ey&or" i! a !pecific &or"% phra!e% or co"ethat a proram un"er!tan"! a! an in!truction# 4ome )eyboar"! inclu"e )ey! that !en" comman" to aproram &hen you pre!! them#

In!tea" of reuirin you to remember )ey&or"! or !pecial )ey!% many proram! allo& you to i!!uecomman"! by !electin menu choice! or raphical ob>ect!# 9or e'ample% proram! that are menu*"rivenprovi"e menu! a! a mean! of enterin comman"!# To"ay% mo!t proram! have a raphical u!er interfacethat u!e icon!% button!% an" other raphical ob>ect! to i!!ue comman"!# Of all of the!e metho"!% araphical u!er interface i! the mo!t u!er* frien"ly &ay to i!!ue comman"!#

A u!er re!pon!e i! an in!truction you i!!ue to the computer by replyin to a ue!tion po!e" by acomputer proram% !uch a!Do you want to save the changes you made: $a!e" on your re!pon!e% theproram perform! certain action!# 9or e'ample% if you an!&er% Ye!% to thi! ue!tion% the proram !ave!your chane" file on a !torae "evice#

8#2 ,3AT ARE I5PUT 6E-ICE47

An input "evicei! any har"&are component that allo&! you to enter "ata% proram!% comman"!% an"u!er re!pon!e! into a computer# Input "evice! inclu"e the )eyboar"% pointin "evice!% !canner! an"rea"in "evice!% "iital camera!% au"io an" vi"eo input "evice!% an" input "evice! for phy!icallychallene" u!er!# Each of the!e input "evice! i! "i!cu!!e" in the follo&in pae!#

8#8# T3E DEY$OAR6

One of the primary input "evice! on a computer i! the )eyboar"# You enter "ata into a computer bypre!!in the )ey! on the )eyboar"# 6e!)top computer )eyboar"! u!ually have from 1=1 to 1= )ey!%&hile )eyboar"! for !maller computer! !uch a! laptop! contain fe&er )ey!# A computer )eyboar"


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inclu"e! )ey! that allo& you to type letter! of the alphabet% number!% !pace!% punctuation mar)!% an"other !ymbol! !uch a! the "ollar !in .J/ an" a!teri!) .K/# A )eyboar" al!o contain! !pecial )ey! thatallo& you to enter "ata an" in!truction! into the computer#

All computer )eyboar"! have a typin area that inclu"e! the letter! of the alphabet% number!%punctuation mar)!% an" other ba!ic )ey!# Many "e!)top computer )eyboar"! al!o have a numeric )eypa"locate" on the riht !i"e of the )eyboar"# A numeric )eypa"i! a calculator*!tyle arranement of )ey!repre!entin number!% a "ecimal point% an" !ome ba!ic mathematical operator!# The numeric )eypa" i!"e!ine" to ma)e it ea!ier to enter number!# Acro!! the top% mo!t )eyboar"! contain function )ey!%&hich are labele" &ith the letter 9 follo&e" by a number#

$un%ton )ey! are !pecial )ey! proramme" to i!!ue comman"! an" accompli!h certain ta!)!# Thecomman" a!!ociate" &ith a function )ey "epen"! on the proram you are u!in# 9or e'ample% in manyproram!% pre!!in the function )ey 9l "i!play! a 3elp &in"o ,hen in!tructe" to pre!! a function )ey!uch a! 9l% "o not pre!! the letter 9 follo&e" by the number 1( in!tea" pre!! the )ey labelle" 9l# 9unction)ey! often are u!e" in combination &ith other !pecial )ey! .43I9T% CTRL% ALT% an" other!/ to i!!uecomman"!# Many proram! let you u!e a !hortcut menu% a button% a menu% or a function )ey to obtainthe !ame re!ult#

Deyboar"! al!o contain )ey! that can be u!e" to po!ition the in!ertion point on the !creen# The in!ertionpoint i! a !ymbol that in"icate! &here on the !creen the ne't character you type &ill "i!play# 6epen"inon the proram% the !ymbol may be a vertical bar% a rectanle% or an un"erline. Arro& )ey! allo& you tomove the in!ertion point left% riht% up% or "o&n# Mo!t )eyboar"! al!o contain )ey! !uch a! 3OME%E56% PA@E UP% an" PA@E 6O,5% that you can pre!! to move the in!ertion point to the beinnin oren" of a line% pae% or "ocument#

Mo!t )eyboar"! al!o inclu"e tole )ey!% &hich can be !&itche" bet&een t&o "ifferent !tate!# The 5UMLOCD )ey% for e'ample% i! a tole )ey# ,hen you pre!! it once% it loc)! the numeric )eypa" !o you canu!e it to type number!# ,hen you pre!! the 5UM LOCD )ey aain% the numeric )eypa" i! unloc)e" !othe !ame )ey! !erve a! arro& )ey! that move the in!ertion point# Many )eyboar"! have !tatu! liht! inthe upper*riht corner that liht up to in"icate that a tole )ey i! activate"#

Many of the ne&er )eyboar"! inclu"e button! that allo& you to acce!! your C6G6-6 "rive an" a">u!t!pea)er volume#

3.3.1 ey'oard +ypes

A !tan"ar" computer )eyboar" !ometime! i! calle" a ,ERTY )eyboar" becau!e of the layoutof it! typin area# Pronounce" D,ER*tee% thi! )eyboar" layout i! name" after the fir!t !i'leftmo!t letter! on the top alphabetic line of the )eyboar"# $ecau!e of the &ay the )ey! areorani0e"% a ,ERTY )eyboar" miht limit your typin !pee"#A )eyboar" &ith an alternative layout &a! "e!ine" to improve typin !pee"# Calle" the 6vora))eyboar" .pronounce" "e*-OR*0ha)/% thi! type of )eyboar" place! the mo!t freuently type"

letter! in the mi""le of the typin area# 6e!pite the more loical "e!in of the 6vora) )eyboar"%the ,ERTY )eyboar" i! more &i"ely u!e"#

Mo!t of to"ay+! "e!)top computer )eyboar"! are enhance" )eyboar"!% &hich mean! they havet&elve function )ey! alon the top% t&o CTRL )ey!% t&o ALT )ey!% an" a !et of arro& an"a""itional )ey! bet&een the typin area an" the numeric )eypa"#

Althouh mo!t )eyboar"! attach to a !erial port on the !y!tem unit via a cable% !ome )eyboar"! *calle" &irele!! )eyboar"! * tran!mit "ata via infrare" liht &ave!# 9or a &irele!! )eyboar" totran!mit !inal! to a computer% both the computer an" the &irele!! )eyboar" mu!t have an r6A


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port# The!e Ir6A port! mu!t be aline" !o that nothin ob!truct! the path of the infrare" liht&ave#

On laptop! an" many han"hel" computer!% the )eyboar" i! built into the top of the !y!tem unit#To fit in the!e !maller computer!% the )eyboar"! u!ually are !maller an" have fe&er )ey!# Atypical laptop computer )eyboar"% for e'ample% ha! only )ey!% compare" to the 1= )ey! onmo!t "e!)top computer )eyboar"!# To provi"e all of the functionality of a "e!)top computer)eyboar"% manufacturer! "e!in many of the )ey! to !erve t&o or three "ifferent purpo!e!#

8#? POI5TI5@ 6E-ICE4

A pointin "evice i! an input "evice that allo&! you to control a pointer on the !creen# In a raphicalu!er interface% a pointer i! a !mall !ymbol on the "i!play !creen. A pointer often ta)e! the !hape of abloc) arro&% an I*beam .T/ or a pointin han"# U!in a pointin "evice% you can po!ition the pointer tomove or !elect item! on the !creen# 9or e'ample% you can u!e a pointin "evice to move the in!ertionpoint( !elect te't% raphic!% an" other ob>ect!( an" clic) button!% icon!% lin)!% an" menu comman"!#

Common pointin "evice! inclu"e the mou!e% trac)ball% touchpa"% pointin !tic)% >oy!tic)% touch !creen%liht pen% an" raphic! tablet# Each of the!e "evice! i! "i!cu!!e" in the follo&in !ection!#

3.4.1"ouse

The mou!e i! the mo!t &i"ely u!e" pointin "evice on "e!)top computer! becau!e it ta)e! fulla"vantae of a raphical u!er interface# 6e!ine" to fit comfortably un"er the palm of your han"%a mou!e i! an input "evice that i! u!e" to control the movement of the pointer% often calle" amou!e pointer% on the !creen an" to ma)e !election! from the !creen# The top of the mou!e ha!one to four button!( !ome al!o have a !mall &heel# The bottom of a mou!e i! flat an" contain! amulti*"irectional mechani!m% u!ually either a !mall ball or an optical !en!or% &hich "etect!movement of the mou!e# Mou!e "evice! that contain a !mall ball often re!t on a mou!e pa"!&hich u!ually i! a rectanular rubber or foam pa" that provi"e! better traction for the mou!e thanthe top of a "e!)# The mou!e pa" al!o protect! the ball mechani!m from a buil" up of "u!t an""irt% &hich coul" cau!e it to malfunction#

USING A MOUSE A! you move the mou!e acro!! a flat !urface !uch a! a "e!)top% the pointeron the !creen al!o move!# 9or e'ample% &hen you move the mou!e to the riht% the pointermove! riht on the !creen## ,hen you move the mou!e to the left% the pointer move! left on the!creen% an" !o on# If you have never &or)e" &ith a mou!e% you miht fin" it a little a&)&ar" atfir!t( &ith a little practice% ho&ever% you &ill "i!cover that a mou!e i! uite ea!y to u!e#

@enerally% you u!e the mou!e to move the pointer on the !creen to an ob>ect !uch a! a button% amenu% an icon% a lin)% or te't an" then pre!! one of the mou!e button! to perform a certain actionon that ob>ect# In ,in"o&! % for e'ample% if you point to the 4tart button on the ta!)bar an"

then pre!!% or %l%! the primary mou!e button% the 4tart menu "i!play! on the !creen#

3.4.& +rac6'all

4ome u!er! opt for alternative pointin "evice! other than a mou!e% !uch a! a trac)ball# ,herea! a mechanical

mou!e ha! a ball mechani!m on the bottom% a trac)ball i! a !tationary pointin "evice &ith a ball mechani!m on it!

top# The ball mechani!m in a larer trac)ball i! about the !i0e of a Pin*Pon ball( !ome mou!e "evice! al!o have a

!mall trac)ball about the !i0e of a marble#

To move the pointer u!in a trac)ball% you rotate the ball mechani!m &ith your thumb% finer!%


19/69

or the palm of your han"# Aroun" the ball mechani!m% u!ually a trac)*ball al!o ha! one or morebutton! that &or) >u!t li)e mou!e button!#

Althouh it !hare! characteri!tic! &ith a mou!e% a trac)ball i! not a! accurate a! a mou!e# Atrac)ball+! ball mechani!m al!o reuire! freuent cleanin becau!e it pic)! up oil! from yourfiner! an" "u!t from the environment# If you have limite" "e!) !pace% ho&ever% a trac)ball i! aoo" alternative to a mou!e becau!e you "o not have to move the entire "evice#

3.4.3 +ouchpad

A touchpa" or trac)pa" i! a !mall% flat% rectanular pointin "evice that i! !en!itive to pre!!urean" motion# To move the pointer u!in a touchpa"% you !li"e your finertip acro!! the !urface ofthe pa"# 4ome touchpa"! have one or more button! aroun" the e"e of the pa" that &or) li)emou!e button!( on other!% you tap the pa"+! !urface to !imulate mou!e operation! !uch a!clic)in#

Althouh you can attach a !tan"*alone touchpa" to any per!onal computer% touchpa"! are foun"more often on laptop computer!#

3.4.4 Stic6A pointin !tic) i! a pre!!ure*!en!itive pointin "evice !hape" li)e a pencil era!er that &a! fir!t

"evelope" by I$M for it! laptop computer!# $ecau!e of it! !mall !i0e% the pointin !tic) i!po!itione" bet&een )ey! on the )eyboar"# To move the pointer u!in a pointin !tic)% you pu!hthe pointin !tic) &ith your finer# The pointer on the !creen move! in the "irection that youpu!h the pointin !tic)#

One a"vantae of u!in a pointin !tic) i! that it "oe! not reuire any a""itional "e!) !pace#Another a"vantae i! that it "oe! not reuire cleanin li)e a mechanical mou!e or trac)ball#,hether you !elect a laptop that ha! a trac)ball% touchpa"% or pointin !tic) i! a matter ofper!onal preference#

3.4.% ;oystic6U!er! runnin ame !oft&are !uch a! a "rivin or fliht !imulator may prefer to u!e a >oy!tic) a!

their pointin "evice# A >oy!tic) i! a vertical lever mounte" on a ba!e# You move the lever in"ifferent "irection! to control the action! of a vehicle or player# The lever u!ually inclu"e!button! calle" triggers that you can pre!! to activate certain event!# 4ome >oy!tic)! al!o havea""itional button! that you can !et to perform other action!#

3.4.9 +ouch Screen

A monitor that ha! a touch*!en!itive panel on the !creen i! calle" a touch !creen# You interact&ith the computer by touchin area! of the !creen &ith your finer% &hich act! a! an input"evice# $ecau!e they reuire a lot of arm movement!% touch !creen! are not u!e" to enter lareamount! of "ata# In!tea" you touch &or"!% picture!% number!% or location! i"entifie" on the!creen#

3.4.5 )en Input

Many input "evice! u!e an electronic pen in!tea" of a )eyboar" or mou!e for input# 4ome of the!e "evice! reuire

you to point to on!creen ob>ect! &ith the pen( other! allo& you to input "ata u!in "ra&in!% han"&ritin% an" other

!ymbol! that are &ritten &ith the pen on a !urface#

3.4.7 /I+ )*,


20/69

A liht pen i! a han"hel" input "evice that contain! a liht !ource or can "etect liht# 4ome lihtpen! reuire a !pecially "e!ine" monitor% &hile other! &or) &ith a !tan"ar" monitor# In!tea" oftouchin the !creen &ith your finer to interact &ith the computer% you pre!! the liht pen aain!tthe !urface of the !creen or point the liht pen at the !creen an" then pre!! a button on the pen#Liht pen! are u!e" in application! &here "e!)top !pace i! limite" !uch a! in the health*care fiel"or &hen a &i"e variety of people u!e the application% !uch a! electronic votin#

3.4.< )*, C!")U+I,

Many han"hel" computer! al!o allo& you to input "ata u!in an electronic pen# The pen .al!ocalle" a !tylu!/ loo)! li)e a ballpoint pen but u!e! an electronic hea" in!tea" of in)# Pencomputer! u!e han"&ritin reconition !oft&are that tran!late! the letter! an" !ymbol! u!e" inhan"&ritin into character "ata that the computer can u!e# Althouh mo!t han"&ritinreconition !oft&are reconi0e! printe" letter! an" can be traine" to "i!tinui!h &ritin !tyle!%pen*computin technoloy continue! to be refine"#

3.4.1= ()ICS +(/*+

A raphic! tablet% al!o calle" a "iiti0er or "iiti0in tablet% con!i!t! of a flat% rectanular%electronic pla!tic boar" u!e" to input "ra&in!% !)etche!% or other raphical "ata# Each locationon the raphic! tablet corre!pon"! to a !pecific location on the !creen# ,hen you "ra& on the

tablet &ith either an electronic pen or a puc)% the tablet "etect! an" convert! the movement! into"iital !inal! that are !ent into the computer# A puc) i! a "evice that loo)! !imilar to a mou!e%e'cept that i! ha! a &in"o& &ith cro!! hair! !o the u!er can !ee throuh to the tablet# U!er! &ithpreci!e pointin reuirement! !uch a! mapma)er! an" architect! u!e a puc)#

8# 4CA55ER4 A56 REA6I5@ 6E-ICE4

4ome "evice! ma)e the input proce!! more efficient by eliminatin the manual entry of "ata# In!tea" ofa per!on enterin "ata u!in a )eyboar" or pointin "evice% the!e "evice! capture "ata from a !ource"ocument% &hich i! the oriinal form of the "ata# ,hen u!in a )eyboar" or pointin "evice to enter"ata% the !ource "ocument miht be a timecar"% or"er blan)% invoice% or any other "ocument thatcontain! "ata to be proce!!e"#

6evice! that capture "ata "irectly from !ource "ocument! inclu"e optical !canner!% optical characterreconition "evice!% optical mar) reconition "evice!% bar co"e !canner!% an" manetic*in) characterreconition rea"er!# E'ample! of !ource "ocument! u!e" &ith the!e "evice! inclu"e a"verti!ement!%brochure!% photoraph!% inventory ta!% or chec)!# Each of the!e "evice! i! "i!cu!!e" in the follo&inpae!#

3.%.1 !ptical Scanner

An optical !canner% u!ually !imply calle" a !canner% i! a liht*!en!in input "evice that rea"!printe" te't an" raphic! an" then tran!late! the re!ult! into a form the computer can u!e .9iure8*1/# A !canner i! !imilar to a copy machine e'cept that it create! a file of the "ocument in!tea"of a paper copy# The file that contain! the !canne" ob>ect then can be !tore" on a "i!)% "i!playe"on the !creen% printe"% fa'e"% !ent via electronic mail% orinclu"e" in another "ocument# 9or e'ample% you can !can a picture an" then incorporate thepicture into a brochure u!in a "e!)top publi!hin proram#

,hen a "ocument i! !canne"% the re!ult! are !tore" in ro&! an" column! of "ot! calle" a bitmap#Each "ot on a bitmap con!i!t! of one or more bit! of "ata# The more bit! u!e" to repre!ent a "ot%the more color! an" !ha"e! of ray that can be repre!ente"# 9or in!tance% one bit per "ot i!enouh to repre!ent !imple one*color imae!% but for color! an" !ha"e! of ray% each "ot reuire!more than one bit of "ata# To"ay+! !canner! rane from 8= bit to ? bit% &ith the latter bein a


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hiher uality% but more e'pen!ive#The "en!ity of the "ot!% )no&n a! the re!olution% "etermine! !harpne!! an" clearne!! of there!ultin imae. Re!olution typically i! mea!ure" in "ot! per inch ."pi/% an" i! !tate" a! the numberof column! an" ro&! of "ot!# 9or e'ample% a == ' 12== .pronounce" == by 12==/ "pi !canner ha!== column! an" 12== ro&! of "ot!# If >u!t one number i! !tate"% !uch a! 12== "pi% that numberrefer! to both the number of ro&! an" the number of column!# The more "ot!% the better there!olution% an" the re!ultin imae i! of hiher uality#

4ome manufacturer! refer to the actual !canne" re!olution a! the optical resolution#

"ifferentiatin it from enhanced or interpolated resolution. The enhance" re!olution u!ually i!hiher becau!e it u!e! a !pecial formula to a"" "ot! bet&een tho!e enerate" by the opticalre!olution#

Mo!t of to"ay+! affor"able color "e!)top !canner! for the home or !mall bu!ine!! u!er have anoptical re!olution ranin from == to 2=== "pi# Commercial !canner! "e!ine" for po&er u!er!rane from ?=== to === "pi#

Orani0ation! u!e many type! of !canner! for imae proce!!in% or imain%&hich con!i!t! ofcapturin% !torin% analy0in% "i!playin% printin% an" manipulatin imae! .bitmap!/# Imaeproce!!in enable! orani0ation! to convert paper "ocument! !uch a! report!% memo!% an"proce"ure manual! into an electronic form# Once !ave" electronically% the routin of the!e

"ocument! can be automate"# They al!o can be !tore" an" in"e'e" u!in an imae proce!!in!y!tem% &hich !erve! a! an electronic filin cabinet that provi"e! acce!! to e'act repro"uction! ofthe oriinal "ocument!# The overnment% for e'ample% u!e! an imae proce!!in !y!tem to !toreproperty "ee"! an" title! to provi"e uic) acce!! to the public% la&yer!% an" loan officer!#

3.%.& !ptical eaders

An optical rea"eri! a "evice that u!e! a liht !ource to rea" character!% mar)!% an" co"e! an"then convert! them into "iital "ata that can be proce!!e" by a computer# The follo&in !ection!"i!cu!! three type! of optical rea"er!B optical character reconition% optical mar) reconition% an"bar co"e#

!)+IC(/ C((C+* *C!,I+I!,

Optical character reconition .OCR/ i! a technoloy that involve! rea"in type&ritten%computer*printe"% or han"&ritten character! from*or"inary "ocument! an" tran!latin theimae! into a form that the computer can un"er!tan"# Mo!t OCR "evice! inclu"e a !malloptical !canner for rea"in character! an" !ophi!ticate" !oft&are for analy0in &hat i!rea"#

OCR "evice! rane from lare machine! that can rea" thou!an"! of "ocument! perminute to han"hel" &an"! that rea" one "ocument at a time# OCR "evice! are u!e" torea" character! printe" u!in an OCR font# Althouh other! e'i!t% the !tan"ar" OCR fonti! calle" OCR*A# 6urin the !can of a "ocument% an OCR "evice "etermine! the !hape!

of character! by "etectin pattern! of liht an" "ar)# Optical character reconition .OCR/!oft&arethen compare! the!e !hape! &ith pre"efine" !hape! !tore" in memory an"convert! the !hape! into character! the computer can un"er!tan"#

OCR !oft&are al!o i! u!e" &ith optical !canner! !uch a! flatbe"% !heet*fe"% an" pen!canner!# 9or e'ample% !uppo!e you nee" to mo"ify a bu!ine!! report% but "o not have theoriinal &or" proce!!in file# You coul" u!e a flatbe" !canner to !can the "ocument% butyou !till &oul" not be able to e"it the report# The !canner% &hich "oe! not "ifferentiatebet&een te't an" raphic!% &ill !ave the report a! a bitmap imae% &hich cannot be e"ite""irectly in a &or" proce!!in proram# To convert it into an e"itable te't file that can bee"ite"% you mu!t have optical character reconition .OCR/ !oft&are that &or)! &ith the


22/69

!canner# The re!ultin output can be !tore" in a variety of file format!% inclu"in tho!ereconi0e" by &or" proce!!in !oft&are#

!ptical "ar6 ecognition >!"?

Optical mar) reconition .OMR/ "evice! rea" han"*"ra&n mar)! !uch a! !mall circle! orrectanle!# A per!on place! the!e mar)! on a form% !uch a! te!t% !urvey% or ue!tionnairean!&er !heet .9iure 8*8/# The OMR "evice fir!t rea"! a ma!ter "ocument% !uch a! an

an!&er )ey !heet for a te!t% to recor" correct an!&er! ba!e" on pattern! of liht( theremainin "ocument! then are pa!!e" throuh the OMR "evice an" pattern! of liht arematche" aain!t the ma!ter "ocument#

ar Code Scanners

A bar co"e !canner u!e! lea!er beam! to rea" bar co"e! .9iure 8*?/# A bar co"e !canner!i! an i"entification co"e that con!i!t! of a !et of vertical line! an" !pace! of "ifferent&i"th!# The bar co"e% &hich repre!ent! !ome "ata that i"entifie! the item% i! printe" on apro"uct+! pac)ae or on a label that i! affi'e" to a pro"uct !o it can be rea" by a bar co"e

!canner# The bar co"e !canner u!e! liht pattern! form the bar co"e line! to i"entify theitem#

$ar co"e! are u!e" on a variety of pro"uct! !uch a! rocerie!% pharmacy !upplie!%vehicle!% mail% an" boo)!# Each in"u!try u!e! it! o&n type of bar co"e# 9or e'ample% theU#4# Po!tal 4ervice u!e! a PO4T5ET bar co"e% &hile retail an" rocery !tore! u!e theUniver!al Pro"uct Co"e% or UPC .9iure 8*/# The table in 9iure 8* !ummari0e! !omeof the more &i"ely% u!e" type! of bar co"e!#

3.%.3 "agnetic In6 Character ecognition eader

A manetic*in) character reconition .MICR/ rea"er i! u!e" to rea" te't printe" &ith maneti0e"in)# MICR i! u!e" almo!t e'clu!ively by the ban)in in"u!try for chec) proce!!in# Each chec)in your chec)boo) ha! preco"e" MICR character! on the lo&er*left e"e( the!e character!repre!ent the ban) number% your account number% an" the chec) number#

,hen a chec) i! pre!ente" for payment% the ban) u!e! an MICR in!criber to print the amount ofthe chec) in MICR character! in the lo&er*riht corner .9iure 8*


23/69

0igure 3-4 +he "IC characters printed on the chec6 represent the 'an6 num'er# your account num'er#

and the chec6 num'er. +he amount of the chec6 in the lower-right corer is added after you write the chec6.

The ban)in in"u!try ha! e!tabli!he" an international !tan"ar" not only for ban) number!% but al!o for the font of theMICR character!# Thi! !tan"ar"i0ation ma)e! it po!!ible for you to &rite chec)! in another country

3.%.4 Data Collection Devices

In!tea" of rea"in or !cannin "ata from a !ource "ocument% "ata collection "evice! are "e!ine"an" u!e" to obtain "ata "irectly at the location &here the tran!action or event ta)e! place# 6atacollection "evice! are u!e" in factorie!% &arehou!e!% or other location! &here heat% humi"ity% an"cleanline!! are "ifficult to control# An e'ample of thi! type of environment i! a re!earcher &homu!t be out!i"e in the element! &hen collectin the "ata .point!% line!% an" area feature!/ for aeoraphic information !y!tem .@I4/# The "ata collection "evice! u!e" to ather "ata for a @I4thu! are rue" an" "urable% allo&in re!earcher! to create map!% analy0e an" interpret "ata forthe map!% an" capture imae! from the air or the roun"#

8# 6I@ITAL CAMERA4

A "iital camera allo&! you to ta)e picture! an" !tore the photoraphe" imae! "iitally in!tea" of ontra"itional film# ,ith !ome "iital camera!% you "o&nloa"% or tran!fer a copy of% the !tore" picture! toyour computer by connectin a cable bet&een the "iital camera an" your computer an" u!in !pecial!oft&are inclu"e" &ith the camera# ,ith other "iital camera!% the picture! are !tore" "irectly on !toraeme"ia !uch a! a floppy "i!)% PC Car"% or fla!h car"# You then copy the picture! to your computer byin!ertin the floppy "i!) into a "i!) "rive or the car" into a car" !lot or rea"er# Once the picture! are onyour computer% they can be e"ite" &ith photo*e"itin !oft&are% printe"% fa'e"% !ent via electronic mail%inclu"e" in another "ocument% or po!te" to a ,eb !ite for everyone to !ee# In!tea" of copyin the imae! to yourcomputer% many of to"ay+! "iital camera! allo& you to revie& an" e"it the imae! "irectly in the camera% a! &ella! connect the camera to a televi!ion or printer#

8#< AU6IO A56 -I6EO I5PUT

Althouh character! .te't an" number!/ are !till the primary form of input into a computer% the u!e ofother type! of input !uch a! imae!% au"io% an" vi"eo i! increa!in# In the previou! !ection!% you learne"about a variety of &ay! to enter imae "ata# The ne't !ection! "i!cu!! metho"! u!e" to enter au"io an"vi"eo "ata into a computer#

3.5.1 (udio Input

Au"io input i! the proce!! of enterin .recor"in/ mu!ic% !peech% or !oun" effect!# To recor" hihuality !oun"% your per!onal computer mu!t have a !oun" car"# .Mo!t ne& computer! to"ay

come euippe" &ith a !oun" car"#/ 4oun" i! entere" via a "evice !uch a! a microphone% tapeplayer% or au"io C6 player% each of &hich plu! into a port on the !oun" car"# E'ternal MI6I"evice! !uch a! an electric piano )eyboar" al!o can connect to the !oun" car" for au"io input#

Recall that% in a""ition to bein a port% MI6I .mu!ical in!trument "iital interface/ i! theelectronic mu!ic in"u!try+! !tan"ar" that "efine! ho& !oun"! are repre!ente" electronically by"iital mu!ical "evice!# 4oft&are proram! that conform to the MI6I !tan"ar" allo& you tocompo!e an" e"it mu!ic an" other !oun"!# 9or e'ample% you can chane the !pee"% a"" note!% orrearrane the !core to pro"uce an entirely ne& !oun"#


24/69

3.5.& Speech ecognition

Another u!e for a microphone i! !peech reconition# 4peech reconition% al!o calle" voicereconition% i! the computer+! capability of "i!tinui!hin !po)en &or"!# 4peech reconitionproram! "o not un"er!tan" !peech( they only reconi0e a vocabulary of certain &or"!# Thevocabulary of !peech reconition proram! can rane from t&o &or"! .!uch a! Ye! an" 5o/ tomore than !i'ty thou!an" &or"!#

4peech reconition proram! are either !pea)er "epen"ent or !pea)er in"epen"ent# ,ith !pea)er*"epen"ent !oft&are! the computer ma)e!a profile of your voice% &hich mean! you have to train the computer to reconi0e your voice# Totrain the computer% you mu!t !pea) each of the &or"! in the vocabulary into the computerrepeate"ly# After hearing the !po)en &or" repeate"ly% the proram "evelop! an" !tore! a "iitalpattern for the &or"# ,hen you later !pea) a &or"% the proram compare! the !po)en &or" totho!e !tore"# 4pea)er*in"epen"ent !oft&are ha! a built*in !et of &or" pattern!% !o you "o nothave to train a computer to reconi0e your voice#

4ome !peech reconition !oft&are reuire! "i!crete !peech% &hich mean! you have to !pea)!lo&ly an" !eparate each &or" &ith a !hort pau!e# 3iher*uality !peech reconition !oft&areallo&! you to !pea) in a flo&in conver!ational tone% calle" continuou!!peech# 4everalcontinuou!*!peech !y!tem! are available for per!onal computer!% an" a"vance! in !peech

reconition continue to be ma"e#

3.5.3 $ideo Input

-i"eo input or vi"eo capturei! the proce!! of enterin a full*motion recor"in into a computeran" !torin the vi"eo on a har" "i!) or !ome other me"ium# To capture vi"eo% you plu a vi"eocamera% -CR% or other vi"eo "evice into a vi"eo capture car"! &hich i! an e'pan!ion car" thatconvert! the analo vi"eo !inal into a "iital !inal that a computer can un"er!tan"# .Mo!t ne&computer! are not euippe" &ith a vi"eo capture car"#/ Once the vi"eo "evice i! connecte" to thevi"eo capture car"% you can bein recor"in# After you !ave the vi"eo on a har" "i!)% you canplay it or e"it it u!in vi"eo*e"itin !oft&are#

u!t a! &ith au"io file!% vi"eo file! can reuire tremen"ou! amount! of !torae !pace# A three*minute !ement% or clip% of hih*uality vi"eo% for e'ample% can ta)e an entire iabyte of!torae .eual to appro'imately %= million pae! of te't/# To "ecrea!e the !i0e of the file!% vi"eooften i! compre!!e"# A popular vi"eo compre!!ion !tan"ar" i! "efine" by the Movin PictureE'pert! @roup .MPE@/# 6-6*ROM! u!e the MPE@ !tan"ar" to compre!! vi"eo "ata#

3.5.4 $ideoconferencing

A vi"eoconferencei! a meetin bet&een t&o or more eoraphically !eparate" in"ivi"ual! &hou!e a net&or) or the Internet to tran!mit au"io an" vi"eo "ata# To participate in avi"eoconference% you mu!t have a microphone% !pea)er!% an" a vi"eo camera mounte" on your

computer# A! you !pea)% member! of the meetin hear your voice on their !pea)er!# Any imaein front of the vi"eo camera% !uch a! a per!on+! face% "i!play! in a &in"o& on each participant+!!creen#

Another &in"o& on the !creen that "i!play! note! an" "ra&in! !imultaneou!ly on all theparticipant!+ !creen!% calle" a &hiteboar"%provi"e! multiple u!er! &ith an area on &hich they can&rite or "ra A! the co!t! of vi"eoconferencin har"&are an" !oft&are continue to "ecrea!e%more people an" companie! are ta)in a"vantae of thi! co!t*effective &ay to con"uct bu!ine!!meetin!% corporate trainin% an" e"ucational cla!!e!#


25/69

8# I5PUT 6E-ICE4 9OR P3Y4ICALLY C3ALLE5@E6 U4ER4

The ro&in pre!ence of computer! in everyone+! live! ha! enerate" an a&arene!! of the nee" toa""re!! computin reuirement! for tho!e &ith phy!ical limitation!#

To"ay% the American! &ith 6i!abilitie! Act .A6A' reuire! that any company &ith 1 or moreemployee! ma)e rea!onable attempt! to accommo"ate the nee"! of phy!ically challene" &or)er!#,hether at &or) or at home% you may fin" it nece!!ary to obtain input "evice! that a""re!! phy!ical

limitation!# $e!i"e! !peech reconition% &hich i! i"eal for blin" or vi!ually impaire" u!er!% !everal otherinput "evice! are available#

U!er! &ith limite" han" mobility that &i!h to u!e a )eyboar" have !everal option!# A )eyuar"! &hich i!place" over the )eyboar"% allo&! you to re!t your han" on the )eyboar" &ithout acci"entally pre!!inany )ey!( a )eyuar" al!o ui"e! your finer or pointin "evice !o you pre!! only one )ey at a time#

Deyboar"! &ith larer )ey! al!o are available# 4till another option i! the !creen*"i!playe" )eyboar"% in&hich a raphic of a !tan"ar" )eyboar" "i!play! on the u!er+! !creen# U!in a pointin "evice% thein"ivi"ual pre!!e! the )ey! on the !creen*"i!playe" )eyboar"#

(#) What s Output*

Output i! "ata that ha! been proce!!e" into a u!eful form calle" information# That i!% a computerproce!!e! input into output# Computer! enerate !everal type! of output% "epen"in on the har"&are an"!oft&are bein u!e" an" the reuirement! of the u!er# You may choo!e to "i!play or vie& thi! output ona monitor% print it on a printer% or li!ten to it throuh !pea)er! or a hea"!et# 9our common type! of outputare te't% raphic!% au"io% an" vi"eo#

Te'tcon!i!t! of character! that are u!e" to create &or"!% !entence!% an" pararaph!# Acharacter i! a letter% number% punctuation mar)% or any other !ymbol that reuire! one byte ofcomputer !torae !pace#

@raphic!are "iital repre!entation! of nonte't information !uch a! "ra&in!% chart!% an"photoraph!# @raphic! al!o can be animate"% ivin them the illu!ion of motion# Animation i!create" by "i!playin a !erie! of !till imae! in rapi" !euence#

Many of to"ay+! !oft&are proram! !upport raphic!# 9or e'ample% you can inclu"e aphotoraph in a &or" proce!!in "ocument or create a chart of "ata in a !prea"!heet proram#

4ome !oft&are pac)ae! are "e!ine" !pecifically to create an" e"it raphic!# Paint proram!%for in!tance% allo& you to create raphic! that can be u!e" in brochure!% ne&!letter!% an" ,ebpae!#

Imae e"itin !oft&areallo&! you to alter raphic! by inclu"in enhancement! !uch a! blen"e"color!% animation% an" other !pecial effect!#

Au"io i! mu!ic% !peech% or any other !oun"# Recall that !oun" &ave!% !uch a! the humanvoice or mu!ic% are analo# To !tore !uch !oun"!% a computer convert! the !oun"! from acontinuou! analo !inal into a "iital format# Mo!t output "evice! reuire that the


26/69

computer convert the "iital format bac) into analo !inal!#

-i"eocon!i!t! of imae! that are playe" bac) at !pee"! that provi"e the appearance offull motion# -i"eo often i! capture" &ith a vi"eo input "evice !uch a! a vi"eo camera or-CR# Mo!t vi"eo !inal! are analo( ho&ever% !ome vi"eo "evice! recor" the vi"eoimae! "iitally#

A vi"eo capture car" convert! an analo vi"eo !inal into a "iital !inal that a computer can un"er!tan"# The "iital

!inal then i! !tore" on the computer+! har" "i!)# 4ome output "evice! accept the "iital !inal% &hile other! reuire

that the computer convert the "iital !inal! bac) into analo !inal!#

?#2 ,3AT ARE OUTPUT 6E-ICE47

An output "evice i! any computer component capable of conveyin information to a u!er# Commonlyu!e" output "evice! inclu"e "i!play "evice!% printer!% !pea)er!% hea"!et!% "ata pro>ector!% fac!imilemachine!% an" multifunction "evice!# Each of the!e output "evice! i! "i!cu!!e" in the follo&in pae!#

?#8 6I4PLAY 6E-ICE4

A "i!play "evicei! an output "evice that vi!ually convey! te't% raphic!% an" vi"eo information#Information !ho&n on a "i!play "evice often i! calle" !oft copy !becau!e the information e'i!t!

electronically an" i! "i!playe" for a temporary perio" of time#

6i!play "evice! inclu"e CRT monitor!% flat*panel "i!play!% an" hih*"efinition televi!ion!#

4.3.1 C+ "onitors

A CRT monitor% or monitor% i! a "i!play "evice that con!i!t! of a !creen hou!e" in a pla!tic ormetal ca!e# A color monitor "i!play! te't% raphic!% an" vi"eo information in color. Colormonitor! are u!e" &i"ely &ith all type! of computer! becau!e mo!t of to"ay+! !oft&are i!"e!ine" to "i!play inforlnation in color#

Monitor! that "i!play only one color are Con!i"ere" monochrome# A monochrome monitor"i!play! te't% raphic!% an" vi"eo information in one color .u!ually &hite% amber% or reen/ on ablac) bac)roun"#

$ecau!e monochrome monitor! are le!! e'pen!ive than color monitor!% !ome orani0ation! u!ethem for application! that "o not reuire color or "etaile" raphic!% !uch a! or"er entry#

To enhance the uality of their raphic! "i!play% !ome monochrome monitor! u!e ray !calin%&hich involve! u!in many !ha"e! of ray from &hite to blac) to form the imae!#

Li)e a televi!ion !et% the core of a CRT monitor i! a lare la!! tube calle" a catho"e ray tube

.CRT/. The !creen% &hich i! the front of the tube% i! coate" &ith tiny "ot! of pho!phor materialthat lo& &hen electrically chare"# In!i"e the CRT% an electron beam move! bac) an" forthacro!! the bac) of the !creen% cau!in the "ot! to lo&% &hich pro"uce! an imae on the !creen#

Each "ot% calle" a pi'el.!hort forpicture element/% i! a !inle point in an electronic imae.9iure ?*1?. Monitor! con!i!t of hun"re"!% thou!an"!% or million! of pi'el! arrane" in ro&! an"column! that can be u!e" to create imae!# The pi'el! are !o clo!e toether that they appearconnecte"#

6eterminin &hat !i0e monitor to u!e "epen"! on your inten"e" u!e# A lare monitor allo&! youto vie& more information on the !creen at once% but u!ually i! more e'pen!ive# If you &or) on


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the ,eb or u!e multiple application! at one time% ho&ever% you may &ant to inve!t in at lea!t a1*inch monitor# If you u!e your computer for inten!e raphin application! !uch a! "e!)toppubli!hin an" enineerin% you may &ant an even larer monitor#

4.3.& 0lat-)anel Displays

A flat*panel "i!play i! a liht&eiht% thin !creen that con!ume! le!! po&er than a CR1 monitor#T&o common type! of flat*panel "i!play! are LC6 an" a! pla!ma#

/CD DIS)/(S

LC6 "i!play! commonly are u!e" in laptop computer!% han"hel" computer!% "iital&atche!%+ an" calculator! becau!e they are thinner an" more liht&eiht than CRTmonitor!# ,hile mo!t LC6 "i!play! are color% even tho!e on ne&er mo"el! of han"hel"computer!% !ome "evice! u!e monochrome LC6 "i!play! to !ave battery po&er

Unli)e a CRT monitor% an LC6 "i!play "oe! not u!e a catho"e ray tube .CR1+/ to createimae! on the !creen( it in!tea" u!e! a liui" cry!tal "i!play .LC6/# A liui" cry!tal"i!play .LC6/ha! !pecial molecule! .calle" liui" cry!tal!/ "epo!ite" bet&een t&o!heet! of material# ,hen an electric current pa!!e! throuh them% the molecule! t&i!t%

cau!in !ome liht &ave! to be bloc)e" an" allo&in other! to pa!! throuh% &hich thencreate! the "e!ire" imae! on the !creen#

Li)e CRT monitor!% the LC6 "i!play! u!e" &ith laptop computer! are available in avariety of !i0e!% &ith the more common bein 1?#1% 1%.=# an" 1#? inche!# LC6 "i!play!pro"uce color u!in either pa!!ive matri' or active matri' technoloy#

An active-matri@"i!play u!e! a !eparate tran!i!tor for each color pi'el an" thu! can"i!play hih*uality color that i! vie&able from all anle!# Active*matri' "i!play!!ometime! are calle" +0+"i!play!% name" after the thin*film tran!i!tor .T9T/ technoloythey u!e# $ecau!e they u!e many tran!i!tor!% active*matri' "i!play!# reuire a lot ofpo&er#

Apassive-matri@"i!play u!e! fe&er tran!i!tor! an" reuire! le!! po&er% but it! color"i!play often i! not a! briht a! an active*matri' "i!play# Imae! on a pa!!ivematri'"i!play can be vie&e" be!t &hen you &or) "irectly in front of the "i!play# Pa!!ive*matri'"i!play! are le!! e'pen!ive than active*matri' "i!play!#

,hile LC6 "i!play! are u!e" mo!t often &ith laptop!% !tan"*alone LC6 monitor! al!ocan be u!e" &ith "e!)top computer!. Li)e CRT monitor!% LC6 monitor! are available ina variety of !i0e!% &ith the more common bein 1% 1% an" 2= inche!# .The term monitortypically i! u!e" for "e!)top "i!play "evice!% &hile the term "i!play i! u!e" for "i!play"evice! on portable computer!#/ LC6 monitor! reuire le!! po&er an" ta)e up le!! "e!)!pace than tra"itional CRT monitor!% ma)in them i"eal for u!er! &ith !pace limitation!#

4ome LC6 monitor! even can be mounte" on the &all for increa!e" !pace !avin!#4tan"*alone LC6 monitor!% ho&ever% are more e'pen!ive than CRT monitor!#

as )lasma "onitors

9or even larer "i!play!% !ome lare bu!ine!! or po&er u!er! prefer a! pla!ma monitor!%&hich can mea!ure more than ?2 inche! an" han "irectly on a &all @a! pla!ma monitor!u!e a! pla!ma technoloy% &hich !ub!titute! a layer of a! for the liui" cry!tal materialin an LC6 monitor# ,hen voltae i! applie"% the a! lo&! an" pro"uce! the pi'el! thatform an imae# @a! pla!ma monitor! offer larer !creen !i0e! an" hiher "i!play ualitythan LC6 monitor! but are much more e'pen!ive#


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4.3.3 "onitor Auality

The uality of a monitor+! "i!play "epen"! larely on it! re!olution% "ot pitch% an" refre!h rate#The re!olution% or !harpne!! an" clarity% of a monitor i! relate" "irectly to the number of pi'el! itcan "i!play# Re!olution i! e'pre!!e" a! t&o !eparate number!B the number of column! of pi'el!an" the number of ro&! of pi'el! a monitor can "i!play#

A !creen &ith a ?= ' ?= .pronounce ?= by ?=/ re!olution% for e'ample% can "i!play ?=column! an" ?= ro&! of pi'el! .or a total of 8=


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The number of color! that a vi"eo car" can "i!play i! "etermine" by the number of bit! it u!e! to!tore information about each pi'el# 9or e'ample% an *bit vi"eo car" .al!o calle" *bit color/ u!e! bit! to !tore information about each pi'el an" thu! can "i!play 2 "ifferent color!% a 2?*bitvi"eo car" u!e! 2? bit! to !tore information about each pi'el an" can "i!play 1#< million color!.In ,in"o&!% you can chane the number of "i!playe" color! in the 6i!play Propertie! "ialo bo'.

Over the year!% !everal vi"eo !tan"ar"! have been "evelope" to "efine the re!olution% number ofcolor!% an" other propertie! for variou!type! of monitor!# To"ay% >u!t about every monitor!upport! the !uper vi"eoraphic! array .4-@A/!tan"ar"% &hich al!o !upport! re!olution! an"color! in the -@A !tan"ar"# The table in 9iure ?*2 outline! the !ue!te" re!olution an" numberof "i!playe" color! in the M6A% -@A% F@A% an" 4-@A !tan"ar"!#

?#? PRI5TER4

+printeri! an output "evice that pro"uce! te't an" raphic! on a phy!ical me"ium !uch a! paper ortran!parency film# Printe" information i! calle" har" copy becau!e the information e'i!t! phy!ically an"i! a more permanent form of output than that pre!ente" on a "i!play "evice .!oft copy/#

3ar" copy% al!o calle" a printout%can be printe" in portrait or lan"!cape orientation# A pae &ith portraitorientation i! taller than it i! &i"e% &ith information printe" acro!! the !horter &i"th of the paper( a pae&ith lan"!cape orientationi! &i"er than it i! tall% &ith information printe" acro!! the &i"e!t part of thepaper# Letter!% report!% an" boo)! typically are printe" in portrait orientation( !prea"!heet!% !li"e !ho&!%an" raphic! often are printe" in lan"!cape orientation#

Printin reuirement! vary reatly amon u!er!# 3ome computer u!er! miht print only a hun"re" pae!or fe&er a &ee)# 4mall bu!ine!! computer u!er! miht print !everal hun"re" pae! a "ay# U!er! ofmainframe computer!% !uch a! lare utility companie! that !en" printe" !tatement! to hun"re"! ofthou!an"! of cu!tomer! each month% reuire printer! that are capable of printin thou!an"! of pae! perhour# The!e "ifferent nee"! have re!ulte" in the "evelopment of printer! &ith varyin !pee"!%capabilitie!% an" printin metho"!#

@enerally% printer! can be roupe" into t&o cateorie!B impact an" nonimpact# Printer! in each of the!ecateorie! are "i!cu!!e" in the follo&in !ection!#

4.4.1 Impact )rinters

An impact printerform! character! an" raphic! on a piece of paper by !tri)in a mechani!maain!t an in) ribbon that phy!ically contact! the paper# $ecau!e of the !tri)in activity% impactprinter! enerally are noi!y#

Many impact printer! "o not provi"e letter uality print# Letter uality.L/output i! a uality ofprint acceptable for bu!ine!! letter!# Many impact printer! pro"uce near letter uality .5L/

print% &hich i! !lihtly le!! clear than letter uality# 5L impact printer! are u!e" for >ob! thatreuire only near letter uality% !uch a! printin mailin label!% envelope!% or invoice!#

Impact printer! al!o are i"eal for printin multipart form! becau!e they ea!ily can print throuhmany layer! of paper# 9inally% impact printer! are u!e" in many factorie! an" at retail counter!becau!e they can &ith!tan" "u!ty environment!% vibration!% an" e'treme temperature!#

T&o commonly u!e" type! of impact printer! are "ot*matri' printer! an" line printer!# Each ofthe!e printer! i! "i!cu!!e" in the follo&in !ection!#


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D!+-"(+IB )I,+*S

A "ot*matri' printer i! an impact printer that pro"uce! printe" imae! &hen tiny &ire pin!on a print hea" mechani!m !tri)e an in)e" ribbon .9iure 4-3?. ,hen the ribbon pre!!e!aain!t the paper% it create! "ot! that form character! an" raphic!#

Mo!t "ot*matri' printer! u!e continuou!,form paper% in &hich each !heet of paper i!

connecte" toether# The pae! enerally have hole! punche" alon t&o oppo!ite !i"e! !othe paper can be fe" throuh the printer# Perforation! alon the in!i"e of the punche"hole! an" at each fol" allo& the !heet! to be !eparate" into!tan"ar"*!i0e" !heet! of paper%!uch a! 1G2 ' 11 inche!# One a"vantae of continuou!*form paper i! that it "oe! not haveto be chane" very often becau!e thou!an"! of pae! are connecte" toether# Many "ot*matri' printer! al!o can be a">u!te" to print pae! in either portrait or lan"!capeorientation#

The print hea" mechani!m on a "ot*matri' printer can contain nine to t&enty*four pin!%"epen"in on the manufacturer an" the printer mo"el# A hiher number of pin! mean!more "ot! are printe"% &hich re!ult! in hiher print uality#

The !pee" of a "ot*matri' printer i! mea!ure" by the number of character! per!econ".cp!/ it can print# The !pee" of "ot*matri' printer! rane! from = to et printer!% la!er printer!% an" thermalprinter!# Each of the!e printer! i! "i!cu!!e" in the follo&in !ection!#


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I,;*+ )I,+*S

An in)*>et printeri! a type of nonimpact printer that form! character! an" raphic! by!prayin tiny "rop! of liui" in) onto a piece of paper# In)*>et printer! u!ually u!ein"ivi"ual !heet! of paper !tore" in a removable or !tationary tray# The!e printer! canpro"uce letter*uality te't an" raphic! in both blac)*an"*&hite an" color on variou!material! !uch a! envelope!% label!% tran!parencie!% an" iron*on t*!hirt tran!fer!% a! &ell a!a variety of paper type!# 4ome in)*>et printer! can print photo*uality imae! on any typeof paper% &hile other in)*>et printer! reuire a heavier &eiht premium paper for better*

loo)in color "ocument!# Many in)*>et printer! are !ol" &ith !oft&are for creatinreetin car"!% banner!% bu!ine!! car"!% letterhea"!% an" tran!parencie!#

$ecau!e of their rea!onable co!t an" letter*uality print% in)*>et printer! have become themo!t popular type of color printer for u!e in the home# You can purcha!e an in)*>et printerof rea!onable uality for a fe& hun"re" "ollar!#

One factor that "etermine! the uality c an in)*>et printer i! it! re!olution% or !harpne!!an" clarity# Printer re!olution i! mea!ure" by the number of "ot! per inch ."pi/ a printercan output# The hiher the "pi% the better the print uality# ,ith an in)*>et printer% a "ot i!a "rop of in)# A hiher "pi mean! the "rop! of in) are !maller% &hich provi"e! a hiheruality imae Mo!t in)*>et printer! have a "pi that rane! from 8== to 1%??= "pi#

Typically% printer! &ith a hiher "pi are more e'pen!ive#The !pee" of an in)*>et printer i! mea!ure" by the number of pae! per minute .ppm/itcan print# Mo!t in)*>et printer! print from one to t&elve pae! per minute .ppm/#@raphic! an" color! print at the !lo&er rate#

The print hea" mechani!m of an in)*>et printer contain! in)*fille" print cartri"e!% each&ith fifty to !everal hun"re" !mall in) hole!% or no00le!# The !tep! in 9iure ?*? illu!trateho& a "rop of in) appear! on a pae# Each no00le in the print cartri"e i! !imilar to anin"ivi"ual pin on a "ot*matri' printer# u!t a! any combination of "ot*matri' pin! can beactivate"% in) can be propelle" by heat or pre!!ure throuh any combination of theno00le! to form a character or imae on the paper#

,hen the print cartri"e run! out of in)% you !imply replace the cartri"e# Mo!t in)*>etprinter! have at lea!t t&o print cartri"e!B one containin blac) in) an" the other.!/containin color!#

/(S* )I,+*S

A la!er printeri! a hih*!pee"% hih*uality nonimpact printer. La!er printer! for per!onalcomputer! u!ually u!e in"ivi"ual !heet! of paper !tore" in a removable tray that !li"e!into the printer ca!e# 4ome la!er printer! have tray! that can accommo"ate "ifferent !i0e!of paper% &hile other! reuire !eparate tray! for letter* an" leal*!i0e" paper# Mo!t la!erprinter! have a manual fee" !lot &here you can in!ert in"ivi"ual !heet! an" envelope!#

You al!o can print tran!parencie! on a la!er printer#

La!er printer! can print te't an" raphic! in very hih uality re!olution!% ranin from== "pi to 1%2== "pi# ,hile la!er printer! typically co!t more than in)*>et printer!% theyal!o are much fa!ter% printin te't at !pee"! of four to thirty pae! per minute#

6epen"in on the uality an" !pee" of the printer% the co!t of a blac)*an"*&hite la!erprinter rane! from a fe& hun"re" to !everal thou!an" "ollar!# Althouh color la!erprinter! are available% they are relatively e'pen!ive% &ith price! e'cee"in !everalthou!an" "ollar!# The hiher the re!olution an" !pee"% the more e'pen!ive the printer#3ih*en" fa!t la!er printer! are u!e" &ith mainframe computer!#


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,hen printin a "ocument% la!er printer! proce!! an" !tore the entire pae before theyactually print it# 9or thi! rea!on% la!er printer! !ometime! are calle" pae printer!# 4torina pae before printin reuire! la!er printer! to have a certain amount of memory#

6epen"in on the amount of raphic! you inten" to print% a la!er printer can have up to2== M$ of memory# To print a full*pae ==*"pi picture% for in!tance% you miht nee" M$ of memory on the printer# If your Printer "oe! not have enouh memory to print thepicture% it either &ill print a! much of the picture a! it! memory &ill allo& or it &ill

"i!play an error me!!ae an" not print any of the picture#

La!er printer! u!e !oft&are that enable! them to interpret a pae "e!cription lanuae.P6L/#A P6L tell! the printer ho& to layout the content! of a printe" pae# ,hen youpurcha!e a la!er printer% it come! &ith at lea!t one of t&o common pae "e!criptionlanuae!B PCL or Po!t4cript# 6evelope" by 3e&lett*Pac)ar"% a lea"in printermanufacturer% PCL .Printer Control Lanuae/i! a !tan"ar" printer lanuae "e!ine" to!upport the font! an" layout u!e" in !tan"ar" office "ocument!# Po!t4criptcommonly i!u!e" in fiel"! !uch a! "e!)top publi!hin an" raphic art becau!e it i! "e!ine" forcomple' "ocument! &ith inten!e raphic! an" color!#

+*"(/ )I,+*S

A thermal printerenerate! imae! by pu!hin electrically heate" pin! aain!t heat*!en!itive paper# 4tan"ar" thermal printer! are ine'pen!ive% but the print uality i! lo& an"the imae! ten" to fa"e over time# Thermal printer! are% ho&ever% i"eal for u!e in !mall"evice! !uch a! a""in machine!#

T&o !pecial type! of thermal printer! have a much hiher print uality# A thermal &a'*tran!fer printer! al!o calle" a thermal tran!fer printer%enerate! rich% non*!mearinimae! by u!in heat to melt color*&a' onto heat*!en!itive paper# Thermal &a'*tran!ferprinter! are more e'pen!ive than in)*>et printer!% but le!! e'pen!ive than many color la!er

printer!# A "ye*!ublimation printer% al!o calle" a thermal "ye tran!ferprinter% u!e! heat totran!fer colore" "ye to !pecially coate" paper# ,hile amon the more e'pen!ive type! ofprinter!% "ye*!ublimation printer! can create imae! that are of photoraphic uality#4ome manufacturer! offer a printer for a fe& thou!an" "ollar! that have both capabilitie!%that i!% thermal &a'*tran!fer an" "ye !ublimation#

)orta'le )rinters

A portable printeri! a !mall% liht&eiht printer that allo&! a mobile u!er to print from alaptop or han"hel" computer &hile travellin# $arely &i"er than the paper on &hich theyprint% portable printer! ea!ily can fit in a briefca!e alon!i"e a laptop computer#

4ome portable printer! u!e in)*>et technoloy% &hile other! are thermal or thermal &a'*tran!fer# Portable in)*>et printer! provi"e better output uality than portable thermalprinter!% but u!ually are larer# Many of the!e printer! connect to a parallel port( other!have a built*in infrare" port throuh &hich they communicate &ith the computer#

)lotters and /arge-0ormat )rinters


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Plotter! an" lare*format printer! are !ophi!ticate" printer! u!e" to pro"uce hih*uality"ra&in! !uch a! blueprint!% map!% circuit "iaram!% an" !in!. $ecau!e blueprint!% map!%an" other !uch "ra&in! can be uite lare% the!e printer! typically can han"le paper &ith&i"th! up to = inche!# 4ome plotter! an" lare*format printer! u!e in"ivi"ual !heet! ofpaper% &hile other! ta)e lare roll!# The!e printer! are u!e" in !peciali0e" fiel"! !uch a!enineerin% "raftin% an" raphic art an" u!ually are very co!tly#

T&o ba!ic type! of plotter! are pen plotter! an" electro!tatic plotter!# A pen plotteru!e!

one or more color pen liht beam!% or a !cribin "evice to "ra& on paper ortran!parencie!# Pen plotter! "iffer from other printer! in that they pro"uce continuou!line!% &herea! mo!t printer! enerate line! by printin a clo!ely !pace" !erie! of "ot!#

An electro!tatic plotteru!e! a ro& of chare" &ire! .calle" !tyli/ to "ra& an electro!taticpattern on !pecially coate" paper an" then fu!e! toner to the pattern# The printe" imae i!compo!e" of a !erie! of very !mall "ot!% &hich provi"e hih*uality output#

Operatin li)e an in)*>et printer% but on a much larer !cale% a lare*format printer create!photo*reali!tic uality color print!# U!e" by raphic arti!t!% the!e hih performanceprinter! are u!e" for !in!% po!ter!% an" other "i!play!#

Special-)urpose )rinters

In a""ition to the printer! >u!t "i!cu!!e"% other printer! have been "evelope" for !pecialpurpo!e!. A photo printer i! a color printer "e!ine" to pro"uce photo lab uality picture!"irectly from a "iital camera# A label printer i! a !mall printer that print! on an a"he!ive*type material that can be place" on a variety of item! !uch a! envelope!% "i!)!%au"ioca!!ette!% photoraph!% an" toy!# Many label printer! are u!e" to print bar co"e!#

?% AU6IO OUTPUT

Au"io i! mu!ic% !peech% or any other !oun"# Au"io output "evice! are the component! of a computer thatpro"uce mu!ic% !peech% or other !oun"!% !uch a! beep!# T&o commonly u!e" au"io output "evice! are

!pea)er! an" hea"!et!#

Mo!t per!onal computer! have a !mall internal !pea)er that u!ually output! only lo&*uality !oun"# 9orthi! rea!on% many per!onal computer u!er! a"" hiher*uality !tereo !pea)er! to their computer! orpurcha!e PC! &ith larer !pea)er! built into the !i"e! of the monitor.

To boo!t the lo& ba!! !oun"!% you can a"" a &oofer .al!o calle" a !ub&oofer/# The !tereo !pea)er! an"&oofer are connecte" to port! on the !oun" car"# Mo!t !pea)er! have tone an" volume control! !o youcan a">u!t the!e !ettin!#

?# OT3ER OUTPUT 6E,CE4

Althouh monitor!% printer!% an" !pea)er! are the more &i"ely u!e" output "evice!% many other output"evice! are available for particular u!e! an" application!# The!e inclu"e "ata pro>ector!% fac!imile!% an"multifunction "evice!# Each of the!e "evice! i! "i!cu!!e" in the follo&in !ection!#

4.9.1 Data )roectors

A "ata pro>ectorta)e! the imae that "i!play! on a computer !creen an" pro>ect! it onto a !creen!o that an au"ience of people can !ee the imae clearly. 6ata pro>ector! can be lare "evice!attache" to a ceilin or &all in an au"itorium% or they can be !mall portable "evice!# T&o type! of!maller% lo&er*co!t unit! are LC6 pro>ector! an" 6LP pro>ector!#


34/69

/CD proector

An LC6 pro>ector! &hich u!e! liui" cry!tal "i!play technoloy% attache! "irectly to acomputer an" u!e! it! o&n liht !ource to "i!play the information !ho&n on the computer!creen# $ecau!e LC6 pro>ector! ten" to pro"uce lo&er*uality imae!% !ome u!er! preferto u!e a 6LP pro>ector for !harper% brihter imae!#A "iital liht proce!!in .6LP/ pro>ectoru!e! tiny mirror! to reflect liht% pro"ucincri!p% briht% colorful imae! that remain in focu! an" can be !een clearly even in a &ell*

lit room#

0acsimile >0a@? "achine

A fac!imile .fa'/ machinei! a "evice that tran!mit! an" receive! "ocument! overtelephone line!# The "ocument! can contain te't% "ra&in!% or photoraph!% or can behan"&ritten# ,hen !ent or receive" via a fa' machine% the!e "ocument! are )no&n a!fa'e!# A !tan"*alone fa' machine !can! the oriinal "ocument% convert! the imae into"iiti0e" "ata% an" tran!mit! the "iiti0e" imae. A fa' machine at the receivin en" rea"!the incomin "ata% convert! the "iiti0e" "ata into an imae% an" print! or !tore! a copy ofthe oriinal imae#

9a' capability al!o can be a""e" to your computer u!in a fa' mo"em# A fa' mo"em i! acommunication! "evice that allo&! you to !en" .an" !ometime! receive/ electronic"ocument! a! fa'e!. A fa' mo"em tran!mit! computer*prepare" "ocument!% !uch a! a&or" proce!!in letter% or "ocument! that have been "iiti0e" &ith a !canner or "iitalcamera# A fa' mo"em i! li)e a reular mo"em e'cept that it i! "e

Fundamental of Computers Manual

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