Maxtor 5120 manual Logical Block Addressing

Page 68

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.

GL – 4

Page 67 Page 69
Image 68
Page 67 Page 69
Contents HA RD Drive Produc T MA Nual DiamondMax Plus 92048U8, 91792U7, 91536U6, 91280U5, 91024U4 and 90750U3Revisions Manual No Before You Begin U T I O NContents Product Specifications Handling and InstallationAT Interface Description Host Software InterfaceGlossary Interface CommandsService and Support Figures Introduction Maxtor CorporationManual Organization AbbreviationsSignal Conventions ConventionsKey Words NumberingDiamondMax Plus 5120 Key Features Product DescriptionProduct Features Functional / InterfaceOn-the-Fly Hardware Error Correction Code ECC Logical Block AddressingDefect Management Zone DMZ Software ECC CorrectionRead-Ahead Mode Cache ManagementBuffer Segmentation Automatic Write Reallocation AWRMajor HDA Components Subsystem Configuration Jumper Location/ConfigurationCylinder Limitation Dual Drive SupportProduct Specifications Drive ConfigurationPerformance Specifications Models and CapacitiesPhysical Dimensions Parameter Standard MetricPower Requirements Average Power Mode DefinitionsEPA Energy Star Compliance Environmental LimitsReliability Specifications Shock and VibrationCanadian Emissions Statement Safety Regulatory ComplianceRadiated Electromagnetic Field Emissions EMC Compliance Handling and Installation Hard Drive Handling PrecautionsPre-formatted Drive Important NoticeUnpacking and Inspection Multi-pack Shipping ContainerRepacking Physical InstallationRecommended Mounting Configuration Handling Precautions Tools for InstallationSystem Requirements Drive Identification InformationGeneral Requirements Hard Drive IdentificationSystems Using Cable Select Installing 5.25-inch Mounting Brackets and RailsInstalling in a Device Bay Mounting Drive in SystemAttaching Interface and Power Cables Attaching System CablesBios Cmos Parameters System SetupSetting the Bios Cmos Hard Drive Preparation System Hangs During Boot Pin Description Summary Interface ConnectorAT Interface Description PIN Name Signal Name Signal Description Pin Description TableTiming Parameters Mode PIO TimingDMA Timing Mode MIN MAX Ultra DMA TimingSustained Ultra DMA Data In Burst Device Terminating an Ultra DMA Data In Burst Initiating an Ultra DMA Data Out Burst Device Pausing an Ultra DMA Data Out Burst Device Terminating an Ultra DMA Data Out Burst Error Register Features RegisterHost Software Interface Task File RegistersSector Count Register Sector Number RegisterCylinder Number Registers Device/Head RegisterCommand Register Command Name Command Code Parameters Used SDH SummaryControl Diagnostic Registers Alternate Status RegisterDevice Control Register Digital Input RegisterInterrupt Handling Reset and Interrupt HandlingReset Handling Interface Commands Set Feature CommandsRead Verify Sectors Read CommandsRead Sectors Read DMA Read MultipleWrite Commands Set Multiple ModeWrite Sectors Write Verify SectorsWrite Multiple Write DMASet Feature Commands Set Features ModePower Mode Commands Sleep Mode Initialization Commands Identify Drive15-8 = PIO data transfer mode = Write Cache enabled Initialize Drive Parameters Format Track Seek, Format and Diagnostic CommandsExecute Drive Diagnostic A.R.T. Command Set Execute S.M.A.R.TService and Support Service PolicyNo Quibble Service SupportInternet MaxFax ServiceCustomer Service Access Time GlossaryCylinder Zero Gigabyte GB Logical Block Addressing Read Gate Signal THIN-FILM Media
Top Page Image Contents