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Chapter 1.  Portable Systems Background

Chapter 1.  Portable Systems Background

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DefiningthePortableComputer

Portables,liketheirdesktopcounterparts,haveevolvedagreat

dealsincethedayswhenthewordportablecouldrefertoa

desktop-sizedsystemwithahandleonit.Today,muchsmaller

portablesystemscanrivaltheperformanceoftheirdesktop

counterpartsinnearlyeveryway.Manyportablesarenowbeing

marketedas"desktopreplacements,"whichareportable

systemspowerfulenoughtoserveasaprimarysystem.This

chapterexaminesthephenomenonofportablecomputing,

showinghowithasevolvedandwhyitissopopular.

Portablesstartedoutassuitcase-sizedsystemsthatdiffered

fromdesktopsmainlyinthatallthecomponents,includinga

CRT-stylemonitor,wereinstalledintoasinglecase.Intheearly

1980s,asmallHouston-basedstartupcompanynamedCompaq

wasamongthefirsttomarketportablePCssuchasthese.

Althoughtheirsize,weight,andappearancearealmost

laughablewhencomparedtotoday'slaptopornotebook

systems,theywerecutting-edgetechnologyforthetime.In

fact,unlikemodernlaptops,thecomponentsusedbythese

bulkyfirstgenerationportableswerevirtuallyidenticaltothose

usedinthemostpowerfuldesktopsoftheday.

Mostcurrentportablesystemsarenowapproximatelythesize

ofthepaper-basednotebooktheyareoftennamedforandare

builtusingtheclamshelldesignthathasbecomeanindustry

standard.Insidethesesystems,nearlyeverycomponenthas

beendevelopedspecificallyforuseinmobilesystems.

PortablePCs,however,arenotthesameasPersonalDigital

Assistants(PDAs),suchasthePalmseries,Handspring,and

PocketPC.PortablecomputersdifferfromPDAsinthattheyuse

thesameoperatingsystemsandapplicationsoftwareas

desktopcomputersandusememory,CPU,anddrive

technologiesthataresimilartodesktopPCsaswell.PDAs,on



theotherhand,usedifferentoperatingsystems,applications,

andhardwarecomparedtoeitherdesktoporportablePCsand

thusfalloutsidethescopeofthisbook.Instead,thisbook

focusesprimarilyonlaptopsornotebook-styleportablePCs.

Thatsaid,intermsoftechnology,muchofthisbookwillalsobe

applicabletoarelativelynewcategoryofportables:TabletPCs.

ActuallyTabletPCshavebeenaroundsincetheearly'90s,buta

lackofstandardizedsoftware,combinedwithrelativelylow

powerandfunctionality,limitedthemtospecialapplications

ratherthanmainstreamuse.Inmanyrespects,modernTablet

PCsareidenticaltolaptop/notebookcomputersexceptthat

theyareequippedwithatouch-sensitivedisplay,lackthe

integratedremovablestorage(suchasaCD/DVD-ROMdrive),

andincludeaspecialtablet-orientedversionofWindows.While

mostincludeakeyboardandbasicallylooklikeastandard

notebookcomputer,afewTabletPCsdonotcomewitha

keyboardatall.Thosethatdon'tincludeakeyboardgenerally

offeroneasanaccessoryorcanuseanystandardexternal

keyboardifdesired.

Manypeopleuseportablesystemsasanadjunctoraccessory

toaprimarydesktopsystemintheirprincipalworkinglocation.

Inthosecases,theportablesystemmaynotneedtohaveall

thepowerofadesktop,sinceitwillonlybeusedwhenaway

fromthemainoffice.Inmysituation,therolesarereversed.All

myprofessionallifeIhavebeenteachingPChardwareand

software,usuallyontheroad.AssuchIhavealwaysneededa

powerfulcomputerIcantakewithme,andbecausetheamount

oftimespenttravelingisequaltoormorethantheamountof

timespentatahomeoffice,IhavehadtorelyonportablePCs

ofonetypeoranotherasmyprimarysystem.

AllmybooksonupgradingandrepairingPCs,startingwithmy

firstself-publishedseminarworkbooksin1985,havebeen

writtenonaportablesystemofonetypeoranother.Withthe

processingpowerofmodernlaptop/notebooksystemsevolving

tothepointwheretheyarenearlyequaltoallbutthemost



powerfuldesktopsystems,Ilookforwardtocarryingeven

smaller,lighter,andmorepowerfullaptopsinthefuture.

Portablecomputershavesettledintoanumberofdistinctroles

thatnowdeterminethesizeandcapabilitiesofthesystems

available.Travelingusershavespecificrequirementsofportable

computers,andtheaddedweightandexpenseincurredby

additionalfeaturesmakeitlesslikelyforausertocarrya

systemmorepowerfulthanisnecessary.Othersmaynotdo

muchtraveling,butsimplyliketheflexibilityandsmallfootprint

thatalaptopprovides.



PortableSystemDesignElements

Obviously,portablesystemsaredesignedtobesmallerand

lighterthandesktops,andmuchofthedevelopmentworkthat

hasbeendoneondesktopcomponentshascertainly

contributedtothisend.Muchofthisdevelopmenthasbeenin

simpleminiaturization.Forexample,whereas3.5-inchhard

drivesmaybepopularondesktops,mostlaptopswouldnot

haveroomforthesedevices.Instead,theynormallyuse2.5inchharddrives,whichareadirectresultoftheminiaturization

thathasoccurredinhard-drivetechnologyoverthepastfew

years.SomeofthesubnotebookandTabletPCsystemsuse

evensmaller1.8-inchdrivesfirstmadepopularinportable

musicplayers.

Inadditiontominiaturization,however,advancementsinthree

otherareashavecontributedgreatlytothedesignoftoday's

laptopcomputers:flat-paneldisplays,powersystems,and

thermalmanagement.



Flat-PanelDisplays

Thesleeklinesofflat-panelLiquidCrystaldisplays(LCDs)have



causedthemtobeseenincreasinglymoreoftenondesktops.It

wasnotlongago,however,thatthesedisplayswerealmost

exclusivelyinthedomainoflaptops.

Aflat-paneldisplayisoneofthemostvisuallyapparent

componentsofalaptop.Theyarealsousuallythecomponent

thathasthegreatestimpactonthesize,shape,andcostofa

laptop.Intheearlydaysofportables,theonlyaffordable

portabledisplaywasthesmallCRTmonitor,adevicethatwas

sopower-hungrythatitrequiredACpower.Thesedisplayswere

alsobulky,causingearlyportablestolooklikesmallsuitcases.

Whengas-plasmadisplaysbecameavailable,thesizeof

portablesdiminishedtothatofalunchboxorbriefcase.Still,the

powerrequirementsofgas-plasmadisplaysagainmandateda

nearbyACoutlet.Itwasnotuntilthedevelopmentoflarge,

low-powerLCDsthatthefamiliarclamshell-style,batterypoweredlaptopbecameareality.

Astheinternalcomponentsofalaptopbecameincreasingly

small,thelaptopsgraduallyshrunkinsizetothepointwhere

theywerenolargerthanapapernotebook.Indeed,the

categoryofnotebookcomputersoriginallystartedoutwitha

footprintnolargerthan8.5x11inches.Inthepastfewyears,

however,ashigh-qualityLCDscreensbecameavailableinlarger

andlargersizes,thesizeofsomenotebooksalsoincreased.



LowPowerConsumption

Likethecarthatspendsmostofitstimeinagarage,orthe

pleasureboatthatspendsmostofitstimeatthedock,portable

computersspendmostoftheirtimeinadecidedlynon-mobile

environmentonadeskconnectedtoanACpoweroutlet.Take

awayalaptop'sbattery,however,andyouhavegreatly

diminisheditsvalue.Infact,oneoftheprimaryfeaturesof

importancetoalaptopbuyeristhe"batterylife"thelengthof

timethesystemcanrunonasinglebatterycharge.



Environmentalconcernsareleadingtothedevelopmentofmore

efficientpower-managementtechnologies,but,obviously,

operatingacomputerfromabatteryimposessystemlimitations

thatdesignersofdesktopsystemsneverhadtoconsiderbefore

theadventofbattery-poweredportablesystems.What'smore,

thedemandforadditionalfeatures,suchasDVDandCD-RW

drives,largerdisplays,andeverfasterprocessors,has

enormouslyincreasedthepowerdrainonthetypicalsystem.

Theproblemofconservingpowerandincreasingthesystem's

batterylifeistypicallyaddressedinthreeways:

Low-powercomponentsNearlyallthecomponentsin

today'sportablesystems,fromCPUstomemorytodisplays

anddrives,arespecificallydesignedtouselesspowerthan

theirdesktopcounterparts.

IncreasedbatteryefficiencyNewerbatterytechnologies,

suchaslithiumionandlithiumpolymer,areenabling

batteriesandpowersuppliestobelighterandhavegreater

capacities,allowingforlongerbatterylifeonasingle

charge.

PowermanagementOperatingsystemsandutilitiesthat

turnoffspecificsystemcomponents,suchasdiskdrives,

whentheyarenotinusecangreatlyincreasebatterylife.



ThermalManagement

Perhapsamoreseriousproblemthanbatterylifeinportable

systemsisheat.Allelectricalcomponentsgenerateheat,of

course,andintheconfinesofalaptopthisheatcanbea

significantproblem.Insidealaptop,alargenumberof

componentsarepackedinarelativelysmallspace,creatingan

extremelyhighconcentrationofthermalenergy.Thisenergy

mustsomehowbedissipated.Inmostdesktopsystems,thisis



accomplishedbyusingfansthatcontinuouslyventilatethe

emptyspacesinsidethesystem.Becausefansuseupbattery

power,however,portablesystemsmustbedesignedtorunfanfreemostofthetimeandthereforeemployinnovativesystems

formovinganddissipatingheat.

Theworstculprit,asfarasheatisconcerned,isthesystem

processor.Whentheywerefirstreleased,theamountofheat

generatedbyIntel's486andPentiumprocessorsbecamea

problemevenindesktopsystems.Newerandfasterprocessors

consumemoreandmorepower.Itbecamecleartoprocessor

manufacturerssuchasIntelandAMDthatspecialprocessor

designswouldbenecessarytoreducepowerconsumptionand

thermaloutputinmobilesystems.Modernmobileprocessors

benefitfromtechnologyfeaturinglowervoltages,smallerdie

sizes,largerintegratedcaches,and,ingeneral,lowerpower

consumptionthantheirpredecessors.

Becausemanyportablesystemsarenowbeingdesignedas

replacementsfordesktops,theyrequirethemostpowerful

processorsavailable.Eventhenewestandfastestprocessors

designedfordesktopsystemsareoftenadaptedforusein

mobilesystems.Evenwithdedicateddesignsformobile

systems,thesehigh-speedprocessorscangeneratesurprisingly

largequantitiesofheat.

Toaddressthisproblem,IntelandAMDhavecreatedspecial

methodsforpackagingmobileprocessorsthataredesignedto

keepheatoutputtoaminimum.Mobileprocessorsalsoreduce

heatthroughtheuseofextra-low-voltagedesigns(multiple

voltagesinrecentdesigns)andbyintegratingboththeLevel1

andLevel2memorycachedirectlyontheprocessordie.These

techniques,bytheway,notonlyreduceheatbutalsolower

powerdemandsandthusincreasebatteryendurance.

However,eventhebestmobileprocessordesignswillstillresult

inasubstantialquantityofheatbeinggeneratedinasmall

space.Usuallythisheatismoreconcentratedthanthatinsidea



desktop.Tocopewiththisproblem,manynotebook

componentsaredesignednotonlytorequirelittlespaceand

powerbutalsotobeabletowithstandhightemperatures.



ThePopularityofPortables

Officestaffersfrequentlyhavetotakeworkhome.Salespeople

regularlycrisscrossthecountry,spendingmoretimeintheir

carsthanattheirdesks.Constructionengineersneed

computingpower,butrarelysitinsideatraditionaloffice.Itis

nowonderthatportablecomputershavehadanalmost

continuouspresenceinthecomputerindustry.Infact,notonly

doportablecomputerscompriseasignificantportionoftotal

annualcomputersales,thatportioniscontinuallygrowing,and

isevenexceedingthatofdesktopsystemsinsomecases.For

example,accordingtotheresearchfirmCurrentAnalysis,

laptopsoutsolddesktopsystemsforthefirsttimeintheU.S.

duringthecalendarmonthofMay,2005,accountingfor53

percentofthetotalmarketduringthatmonth,upfrom46

percentduringthesameperiodinthepreviousyear.

Asfurtherevidenceofthepopularityoflaptops,Intelsaidthat

about31percentofitsprocessorswillendupinmobile

computersin2005,comparedwithonly17percentin1999.

IBMreportedin2000thattheysoldatotalof10million

ThinkPadlaptopsinthe8yearssincetheirfirstappearanceon

themarketin1992.Theydoubledthatfigureto20milliontotal

ThinkPadlaptopsby2003,only3yearslater.Notonlyare

laptopsgrowinginpopularityascomparedtodesktops,butthe

totalmarketforlaptopshasbeenincreasingaswell.According

toDisplaySearchInc.,laptopsalesfor2004wereexpectedto

exceed46millionunits,anastonishingfigurewhenyoulookat

it.

Finally,accordingtoCharlesSmulders,vicepresidentandchief

analystatGartnerDataquest,"…themobilesegmenthas



representedoneofthefewareasofsustainedgrowthinan

otherwisedifficultPCmarket.Between1998andmid-2002,

mobilePCsincreasedtheirunitshareoftheglobalPCmarket

byover50percent.ForeveryfourPCsshipped,oneisnowa

mobile,andthisshareisprojectedtorisefurther,approaching

oneinthreeby2006."



Who'sSellingLaptops?

Becauseoftheirpopularity,laptopandnotebookcomputersare

availablefromalargenumberofvendors.Table1.1liststhe

majorlaptop/notebookvendorsintheU.S.,alongwiththe

brandnamesassociatedwiththosevendors.

Table1.1.MajorLaptop/NotebookVendorsinthe

UnitedStates

Vendor



BrandNames



Acer



TravelMate,Aspire,Ferrari



Alienware



Area-51m,Sentia



Amrel



Rocky



AshtonDigital



Excelente,Maximate,Passport



Asus



Asus



Casio



CassiopeiaFIVAMPC



ChemUSA



ChemBook



Compaq



Evo,Presario



Cybernet



DeskBook



Dell



Inspiron,Latitude,Precision



Dolch



NotePAC



Electrovaya



Scribbler



FOSA



FOSA



FujitsuPC



Celsius,LifeBook,Stylistic



Gateway



Solo



HP



OmniBook,Pavilion



Lenovo/IBM



ThinkPad



Itronix



GoBook



MicronPC,MPC



TransPort



NEC



Versa



Panasonic



ToughBook



Pelican



Executive,Rugged



RuggedNotebooks



Talon,Hawk,RoughRider



Sager



NP



Sceptre



Soundx,Mobility,N-Series



Sharp



Actius,Mebius



Sony



VAIO



Toshiba



Portege,Satellite,SatellitePro,

Tecra



Twinhead



Durabook,Stylebook



ViewSonic



ViewPad



WinBook



WinBook



XploreTechnologies



GeneSYS



Althoughtherearemanyvendorsoflaptops,mostvendorsdo

notmanufacturethesedevicesthemselves.Infact,65%ofall

laptopsareproducedinTaiwanbyoneofseveralcompanies

locatedthere.Thesecompaniesarenotwellknownbecausethe

systemstheymanufactureareusuallynotlabeledwiththeir

ownname,butinsteadareprivatelylabeledwiththenameof

thevendor.Here'salistofthemajormanufacturersinTaiwan;

whilemostofthemsellsystemsunderothernames,afewof

thesecompaniesalsosellsystemsundertheirownlabelsas

well:

Acer



Inventec



Anadem



MiTac



Arima



Quanta



Clevo



Sotec



CMC/Computex



Twinhead



Compal



Wistron



Anincreasingportionofnotebooksisbeingproducedin

mainlandChinaaswell.Thelargestbuilderofnotebooksinthat

countryisLenovo,whoacquiredIBM'sPersonalComputing

Division(globaldesktopandnotebookPCbusiness)in2005.

ThisacquisitionmakesLenovo/IBMthethird-largestglobalPC

leader,behindDellandHP/Compaq.







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Chapter 1.  Portable Systems Background

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