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C DataRecoveryGlossary

CableSelect

(CSEL)

An

alternative

option

which

can

be

used

in

place

of

setting

Master/Slavejumpersinthedesignationofdrivesinadualdriveconfiguration.

Master/Slavedesignationisbasedonthepositionofdrivesrelativetothecable.

Specialcablingisrequiredbythesystemmanufacturertoselectivelygroundthe

CSELsignalononeoftheIDEcableconnectors.Forexample,whenoneofthedrives

isconnectedtothegroundedCSELconductor,itconfiguresitselfasaMaster.When

theseconddriveisconnectedtotheotherconnector,onwhichCSELisnot

grounded,itbecomesslave.Thiseliminatestheneedforuniquejumpring

configurationbetweentheMastersandslavedrives.

CacheHighspeedRAMisusedasabufferbetweentheCPUandaharddrive.The

cacheretainsrecentlyaccessedinformationtospeedupsubsequentaccesstothe

samedata.Whendataisreadfromorwrittentodisk,acopyissavedinacache,

alongwiththeassociateddiskaddress.Thecachemonitorstheaddressesof

subsequentreadoperationstoseeiftherequireddataisalreadyinthecache.Ifitis,

thedrivereturnsthedataimmediately.Ifitisnotinthecache,thanitisfetched

fromthediskandsavedinthecache.

Capacity Theamountofinformation,measuredinbytesthatcanbestoredona

harddrive.

It

is

also

known

as

Storage

Capacity.

CardAcircuitboardthatisusuallydesignedtoplugintoaconnectororslot.See

alsoadapter.

CARAnacronymforrewritableCDstechnologybywhichmediacanbewrittento

anderasedapproximately1,000timesbeforefailure.Standard74minCDRWmedia

canholdupto500MBwhenformattedforfixedlengthpacketwriting.

Channel Aconnectionorsocketonthemotherboardorcontrollercard.Amother

boardmay

have

one

or

two

channels

(primary

and

Secondary).

If

your

motherboard

hasonlyonechannel,youmayneedtoaddacontrollercardtocreateasecondary

channel.

ChannelAssemblyInthecomputerindustry,thefinalassemblyofasystembya

distributororresellerfromkits,providedbythemanufacturerandfromcomponents

shippeddirectlytotheassemblerbysubsystemmakers.

CleanRoomAnenvironmentallycontrolleddustfreeassemblyorrepairfacilityin

whichharddiskdrivesareassembledorcanbeopenedforinternalservicing.See

ourClean

Room

Components

.

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ClickToclickanitemmeanstopointtoitwiththescreenpointer,andthenpress

quicklyandreleasetheleftmousebuttonatonce.

ClusterWindowsallocatespacetofilesinunitscalledClusters.Eachcluster

containsfrom1to64sectors,dependingonthetypeandsizeoftheDisk.Aclusteris

thesmallestunitofDiskspacethatcanbeallocatedfortheusagebythefiles.Ahard

disktermreferstoagroupofsectors,thesmalleststorageunitrecognizedbythe

DOS.Onthemostmodernharddisk,512bytesectorsmakeupacluster,andoneor

moreclustersmakeupatrack.

CMOSApartofthemotherboardthatmaintainsasystemvariableinstaticRAM.It

alsosuppliesarealtimeclockthatkeepstrackofthedate,dayandtime.CMOS

Setupistypicallyaccessiblebyenteringaspecificsequenceofkeystrokesduringthe

POSTatsystemstartup.

ColdBoltStartingorrestartingacomputerbyturningOnthepowersupply.See

alsoWarmBoot.

CommandAgingAnSCSIfeaturethatpreventsthecommandofreordering

algorithmfromkeepingI/Oprocessonwaitinginthecommandqueueforthe

extendedperiodoftime.

CommandQueuingAfeaturethatenablesthedrivetoreceiveI/Oprocessesfrom

oneormoreinitiatorsandexecutetheminanoptimumsequence.

CommandReordering AfeaturethatallowsthedrivetoreorderI/Oprocessesin

thecommandqueue,whichresultsinminimizingtheseektimeandrotational

latencyandthusincreasesthroughput.

ContextMenuAlsocalledacontextsensitivemenu,orashortcutmenu,acontext

menuincludesthecommandswhicharecommonlyassociatedwithanobjectonthe

screen.Toactivateanitemscontextmenu,pointtoitwiththescreenpointer,then

pressandreleasetherightmousebuttononce.

Controller

See

disk

controller,

interface

controller,

and

disk

drive

controller.

ControllerCardAnadapterwithanelectroniccontrolforoneormoreharddrives.

Usuallyinstallinabusslotinthecomputer.

Cookies(InternetBrowser)Holdsinformationonthetimesanddatesyouhave

visitedwebsites.Otherinformationcanalsobesavedtoyourharddiskinthesetext

files,includinginformationaboutonlinepurchases,validationinformationaboutyou

formembersonlywebsites,andmore.

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CorrectableErrorAnerrorthedrivecancorrectbyusingErrorDetectionand

Correctionschemes.

CPUStandsforCentralProcessingUnit,aprogrammablelogicdevicethatperforms

alltheinstruction,logic,andmathematicalprocessinginacomputer.

CrashAsudden,usuallydrasticfailure.Itcanbesaidoftheoperatingsystemora

particularprogramwhenthereisasoftwarefailure.Also,adiskdrivecancrash

becauseofhardwarefailure.

CRCAcronymforCyclicRedundancyCheck.TheCRCisusedtoverifydatablock

integrity.Inatypicalscheme,2CRCbytesareaddedtoeachuserdatablock.The2

bytesarecomputedfromtheuserdata,bydigitallogicalchips.Themathematical

modelismadeupofpolynomialswithbinarycoefficients.Whenreadingbackdata,

theCRC

bytes

are

read

and

compared

to

new

CRC

bytes

computed

from

the

read

backblocktodetectareaderror.Thereadbackerrorcheckprocessis

mathematicallyequivalenttodividingthereadblock,includingitsCRC,bya

binomial.Ifthedivisionremainderiszero,thedataiserrorfree.

CrosslinkedfilesTwofiles,bothrefertothesamedata.

CylinderThecylindricalsurfaceformedbyidenticaltracknumbersonvertically

stackeddiscs.Atanylocationoftheheadpositioningarm,alltracksunderallheads

arethecylinder.Thecylindernumberisoneofthethreeaddresscomponents

requiredto

find

aspecific

address.

The

other

two

are

head

number

and

sector

number.

Cylinder,Head,Sector(CHS)AddressingAmethodofreferencingthesectorsona

drive,asacollectionofuniquecylinders,headandsectoraddresses.Eachblockon

thedrivewillhaveauniquecylinder,headandsectoraddress.

DolphinDataLabhttp://www.dolphindatalab.com/