GLOSSARY

LOGICAL ADDRESS

Astoragelocationaddressthatmaynotrelatedirectlytoaphysicallocation.Usually usedtorequestinformationfromacontroller,whichperformsalogicaltophysical addressconversion,andinturn,retrievesthedatafromaphysicallocationinthemass storageperipheral.

LOGICAL BLOCK ADDRESSING

Definestheaddressingofthedevicebythelinearmappingofsectors.

LOGICAL SECTOR

ThelowestunitofspacethatDOScanaccessthroughadevicedriver;oneormore physicalsectors.

LOW FREQUENCY

Thelowestrecordingfrequencyusedinaparticularmagneticrecordingdevice.With FMorMFMchannelcodes,thisfrequencyisalsocalled“IF.”

M

MAIN MEMORY Random-accessmemory(RAM)usedbythecentralprocessingunit(CPU)forstoring programinstructionsanddatacurrentlybeingprocessedbythoseinstructions.(Seealso randomaccessmemory.)

MASS STORAGE

Auxiliarymemoryusedinconjunctionswithmainmemory;generallyhavingalarge, on-linestoragecapacity.

MEGABYTE (MB)

Aunitofmeasureapproximatelyonemillionbytes(actually1,048,576bytes)or106.

MEMORY

Anydeviceorstoragesystemcapableofstoringandretrievinginformation.(Seealso storagedefinitions.)

MICROCOMPUTER

Acomputerwhosecentralprocessingunitisamicroprocessor.Itisusually,butnot necessarily,desktopsize.

MICROPROCESSOR

Acentralprocessingunit(CPU)manufacturedasachiporasmallnumberofchips.

MISSING PULSE

Atermusedinsurfacecertification.Itiswhenaprerecordedsignalisreducedin amplitudebyacertainspecifiedpercentage.

MODIFIED FREQUENCY MODULATION (MFM)

Amethodofencodingdigitaldatasignalsforrecordingonmagneticmedia.Alsocalled “threefrequencyrecording.”Recordingcodethatonlyusessynchronizingclockpulse ifdatabitsarenotpresent.Doublesthelinealbitdensitywithoutincreasingthelineal fluxreversaldensity,comparedtoFrequencyModulation.

MODIFIED MODIFIED FREQUENCY MODULATION (MMFM)

ArecordingcodesimilartoMFMthathasalongerrunlengthlimiteddistance.

MODULATION

1.Readbackvoltagefluctuationusuallyrelatedtotherotationalperiodofadisk.2.A recordingcode,suchasFM,MFM,orRLL,totranslatebetweenfluxreversalsandbits orbytes.

N

NON-RETURN TO ZERO

Aformofdataencodingthatisnotself-clocking,inotherwords,itneedstobe providedwithanexternalbitcellclocksignal.Generallyusedinhigher-performance diskdrives.

O

OFF-LINE processingorperipheraloperationsperformedwhiledisconnectedfromthesystem CPUviathesystembus.

ON-LINE processingorperipheraloperationsperformedwhiledisconnectedfromthesystem CPUviathesystembus.

OPEN LOOP SERVO

Aheadpositioningsystemthatdoesnotusepositionalinformationtoverifyandcorrect theradiallocationoftheheadrelativetothetrack.Thisisusuallyachievedbyuseofa steppermotorwhichhaspredeterminedstoppingpointthatcorrespondstotrack locations.

OPERATING SYSTEM

Asoftwareprogramthatorganizestheactionsofthepartsofthecomputerandits peripheraldevices.(Seediskoperatingsystem.)

OUTSIDE DIAMETER

Thelargestradiusrecordingtrackonadisk.

OVERWRITE

Atestthatmeasurestheresidual1Frecordedfrequencyonatrackafterbeing overwrittenbya2Fsignal.Variationsofthetestexist.

P

PARALLELISM

1.Theconditionoftwoplanesorlinesbeingparallel.Importantindiskdrivesbecause alackofitinmechanicalassembliescanresultinpositioninginaccuracy.More precisely:planes-coplanar;lines-colinear.2.Isthelocalvariationindiskthickness measuredindependentlyofthicknessitself.3.Theabilityofamultiprocessorcomputer toallocatemorethanoneprocessor(CPU)toacomputingproblem,whereeachCPU worksonaseparateproblemorseparatesegmentofthatproblem.Alsoreferredtoas parallelprocessing.

PARITY

Asimplemethodofdataerrordetectionsthatalwaysmakesnumberseitheroddor even,usinganextrabitinwhichthetotalnumberofbinary1s(or0s)inabyteis alwaysoddoralwayseven;thus,inanoddparityscheme,everybytehaseightbitsof dataandoneparitybit.Ifusingoddparityandthenumberof1bitscomprisingthe byteofdataisnotodd,theninthorparitybitissetto1tocreatetheoddparity.Inthis way,abyteofdatacanbecheckedforaccuratetransmissionbysimplycountingthe bitsforanoddparityindication.Ifthecountisevereven,anerrorisindicated.

PARTITION

Alogicalsectionofadiskdrive,eachofwhichbecomesalogicaldevicewithadrive letter.

PEAK SHIFT

Theshiftingintimeofthezero-slopeportionofareadbackvoltagefromthevalues containedinthewritecurrentwaveform.Sometimesincorrectlyusedtodescribebit jitter.

PERIPHERAL EQUIPMENT

Auxiliarymemory,displays,printers,andotherequipmentusuallyattachedtoa computersystem’sCPUbycontrollersandcables.(Theyareoftenpackagedtogetherin adesktopcomputer.)

PHASE LOCKED LOOP (PLL)

Acircuitwhoseoutputlocksontoandtracksthefrequencyofaninputsignal. Sometimesincorrectlycalledadataseparator.

PHASE MARGIN Measureindegreesoftheamountofdifferencebetweenexcursionsfromthewindow centerwherefluxreversalscanoccurandtheedgeofthedatawindow.Similarto windowmargin.

PHYSICAL SECTOR

Thesmallestgroupingofdataontheharddisk;always512bytes.

PIO

ProgrammableInputOutput.Ameansofaccessingdeviceregisters.Alsodescribesone formofdatatransfers.PIOdatatransfersareperformedbythehostprocessorusing PIOregisteraccessestothedataregister.

PLATED THIN FILM MEDIA

Magneticdiskmemorymediahavingitssurfaceplatedwithathincoatingofametallic alloyinsteadofbeingcoatedwithoxide.

PROCESSING

Theprocessofthecomputerhandling,manipulatingandmodifyingdatasuchas arithmeticcalculation,filelookupandupdating,andwordpressing.

PULSE CROWDING

Modificationofplaybackamplitudeduetosuper-positioningofadjacentfluxreversal fieldsbeingsensedbytheread/writegap.

PULSE DETECT

Adigitalpulsetraininwhicheachleadingedgeoreachedgecorrespondstoa magnetictransitionreadfromthedisk.Iftransitionqualificationcircuitryexistsinthe drive,thissignalistheoutputofsame.Alsoknownastransitiondetect.

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Maxtor 4320 manual Logical Block Addressing

4320 specifications

The Maxtor 4320 is a notable entry in the realm of hard disk drives, widely recognized for its reliability and performance in data storage. Released in the early 2000s, it quickly gained traction among both consumers and professionals looking for efficient solutions for their data management needs.

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