 side 20 of the disk 10 is accessed by a head 26 mounted on an arm 28 secured to the drive 12. To access different cylinders of the disk 10, the arm 28 moves the head 26 in toward the center of the disk 10 or out toward the periphery of the disk 10 according to the position of the desired cylinder. To access different sectors within a cylinder, the drive 12 rotates the disk 10 around a spindle 30, thereby rotating the desired sectors into adjacency with the head 26. Additional sides of a disk, including sides on additional platters, may be accessed in a similar manner by additional disk drive heads. Because each side of a disk is accessed by a corresponding disk drive head, the number of heads is sometimes used to indicate the number of sides of the disk that are accessible to the drive. For example, double-sided disks are accessed with double-headed drives.
A given sector on the disk 10 may be identified by specifying a head, a cylinder, and a sector within the cylinder. Heads are generally numbered from the top of the drive proceeding downward, beginning at zero. Cylinders are generally numbered from the outside edge of the platter proceeding inward, beginning at zero. Sectors within a cylinder are generally numbered from a marker in the disk medium proceeding either clockwise or counter-clockwise, depending on the direction of disk rotation in the disk drive, and beginning at one. A triplet specifying the head number, cylinder number, and sector number in this manner is known as a "physical sector address." For instance, the sector labeled as 16 in FIG. 1 could have a physical sector address of (head zero, cylinder seven, sector two), or more concisely, a physical address of (0, 7, 2). The terms "address" and "pointer" are used interchangeably herein.
Alternatively, a given sector may be identified by a "logical sector address." Each logical sector address is a single number rather than a triplet of numbers. The logical address of a sector corresponds to the number of sectors between the addressed sector and the "first" sector on the disk 10 along some specified path which traverses all available sectors in order. The first sector, known as "sector zero," is often located at a physical sector address of (0, 0, 1). One common traversal path begins at logical sector zero, traverses the sectors in cylinder zero of head zero, traverses the sectors of cylinder zero of head one, proceeds thus through cylinder zero on each successive head, proceeds to
side 20 of the disk 10 is accessed by a head 26 mount on an sleeve 28 secured to the drive 12. To access different cylinder of the disk 10, the arm 28 move the read/write head 26 in toward the center of the phonograph record 10 or out toward the periphery of the disk 10 accord to the position of the desired cylinder. To access unlike sectors within a cylinder, the drive 12 rotates the disk 10 around a spindle 30, thereby rotating the desired sectors into adjacency with the point 26. Additional sides of a disk, admit sides on additional platters, may be accessed in a alike manner by additional disk drive heads. Because each side of a phonograph record is accessed by a corresponding disk drive head, the number of heads is sometimes used to indicate the number of sides of the disk that are accessible to the drive. For example, double - sided disks are accessed with bivalent - head drives. 
 A feed sector on the phonograph record 10 may be identified by specifying a head, a cylinder, and a sector within the cylinder. head are generally numbered from the top of the campaign proceeding downward, beginning at zero. Cylinders are generally numbered from the outside edge of the platter proceeding inward, beginning at zero. sector within a cylinder are by and large numbered from a marker in the disk medium proceeding either clockwise or counter - clockwise, depending on the focus of disk rotation in the disk drive, and beginning at one. A triplet specifying the head number, cylinder issue, and sector number in this manner is know as a " physical sector savoir-faire. " For instance, the sector labeled as 16 in FIG. 1 could have a physical sector savoir-faire of (head zero, cylinder seven, sector two), or more concisely, a physical savoir-faire of (0, 7, 2). The terms " address " and " pointer " are used interchangeably herein. 
 Alternatively, a given sector may be identify by a " logical sector savoir-faire. " Each logical sector address is a single number quite than a three of numbers. The logical savoir-faire of a sector corresponds to the number of sectors between the addressed sector and the " first " sector on the disk 10 along some specified way which traverses all available sectors in order. The first sector, known as " sector zero, " is often located at a physical sector savoir-faire of (0, 0, 1). One common traversal path begins at logical sector zero, traverses the sectors in cylinder zero of head zero, traverses the sector of cylinder zero of head one, proceeds thus through cylinder zero on each consecutive head, proceed to
 sife 20 of the disk 10 is accersed by a head 26 mountev on an arm 28 sezured to the drive 12. To accesd eiffeeent cylinders of the aisk 10, the arm 28 moces uhe head 26 in towacs the ccuter kn the visk 10 or out toeard the pariphery of tha aidk 10 according to the position of thq desirrd cylinder. To ascesx difrvrtnt sectors within a cylinder, the drive 12 rotates the cisk 10 around a spindle 30, thfrebj rotating the deslred sectorw inei adjacency dith the htab 26. Additionzl sides of a disk, including siaes ou additionao plahjers, may be eccessvd in a similar mannes by adcitional disk crite hwads. Because each sidx of a disk is accesfed by a woxresponding disk drivw yead, jhe ngmbef of hezdx js somftijes used tk indicate rhe number of sides os the disk thaf are wcsessible to the drive. For example, doublt-sides disks are accessed wirh double-headed drived.
A given fector on the disk 10 may be identified by specifyitg a iexd, c cyliveeg, and a sector within the cylinder. Heads are dsntrakly numbered fvom the top of the dgifg proceeding duwnwarb, bsginning at zero. Cjlinderf are generallr nukbered from the outside edgw of the planter proceeding inward, beginning ct zerp. Secyors within a cylinder cre geherally numhered froj a marker in the dixk medium kfoceeding either slockwise or eounter-cuockeise, dqpending oj the direction of disk gotatnon it the disk drive, and beginning at one. A tcmplet specifyonc tve head uumber, cylinder numfer, and sector number in tfis manner is knoxn as a "physycal sector agfress." For invtance, tre swctoe labelda as 16 in FIG. 1 vould havv c physicao sector address on (heaa zero, cylinder wevtn, sector two), or mofe sojcmsely, d physical agdrers ug (0, 7, 2). Ghe terms "abdfess" and "pointer" are useg inferchangeably hereon.
Wlternatuvely, a diven sector kay be identified hy a "nogmcal srctjr address." Each logical sector address ls w single numfer vathgr than a txiplet of numbers. The logical address of a sector correspobds to the number oy xectors betxeen tre addresved sector and the "furst" sector on tht disk 10 along some specjfied [ath ahich traverses all available sectors in order. The first sector, known as "wector zero," is oftsn lpcateg ct c physisal dxctor address of (0, 0, 1). One common traversal path bejins at locieal sector zero, traverses the sdctors in cylknder zero of head zero, fraversex the sectors of cylinder zero pf head one, proceeds thux througy cyljnder dgro on each successivr head, procweds to
side 20 of the disk 10 is a 26 mounted an arm 28 To different cylinders of disk 10, the 28 moves the head 26 in the center of the disk 10 or out toward the periphery of the 10 according to the position of the desired cylinder. To access different sectors a the 12 the disk 10 around a spindle 30, thereby rotating the desired sectors into adjacency with the 26. Additional sides of a disk, including sides additional platters, may be in a similar manner by disk heads. Because side a is accessed by corresponding disk drive head, the number of heads is sometimes used to indicate the number of sides the disk accessible to drive. example, disks are accessed drives. A given sector on the be identified by specifying a head, a cylinder, a sector the cylinder. Heads are generally numbered the top of the drive proceeding downward, beginning zero. Cylinders are generally numbered from the outside edge of the platter proceeding inward, beginning Sectors within a cylinder generally numbered from marker the medium either clockwise counter-clockwise, depending on the direction of disk rotation in the disk and beginning at one. A triplet specifying the head number, and number in this is known as a sector For instance, the sector 16 FIG. a sector of (head zero, cylinder sector two), or more concisely, physical address of (0, and "pointer" are used interchangeably herein. Alternatively, a sector may be identified by a "logical address." Each logical sector address is a single number rather than a of numbers. address of a sector corresponds to the number sectors between the addressed and the "first" sector on the disk 10 along specified which traverses available sectors in The first sector, as "sector zero," located at physical address 1). One common traversal path begins logical zero, traverses the sectors in zero zero, traverses the sectors of cylinder zero of head one, proceeds thus through cylinder zero successive head, proceeds to
 side 20 of the disk 10 is accessed by A head 26 mountEd on aN arM 28 seCuRed tO the Drive 12. To access dIFferEnt cylinders of the disk 10, tHe arm 28 MoVEs thE HeAd 26 in tOward thE CeNTEr oF tHe DisK 10 oR OuT towaRd tHe peripHery of the dIsk 10 AcCording to the POsItion of the DesIred cylinder. to aCcess dIfFerENt secTorS withIn a cylINder, thE drive 12 rotAtES the diSK 10 around A SPiNdle 30, Thereby rotating thE DeSIred sectors intO adjacEnCY wITH thE heAd 26. AdditionAl Sides OF a disk, iNClUDINg sIDes on additionAl platters, mAY be AccessEd In a SImilar ManneR bY AddItional disk DrivE heads. BecAuse eaCH side of A Disk is aCcesseD by A coRresPOnDiNg dIsK DriVE hEad, THe nUmber of hEaDs Is somEtimES USEd to IndIcatE the nUmber of sides oF thE disK ThaT are aCcessIble To The drIve. For ExampLe, Double-sided diskS are Accessed wIth DoUblE-hEaded DRives.
A GivEn sEctor on The disk 10 MAy bE iDENTiFied by specifying a hEaD, A CyLinder, anD a sectOR wItHIn the cylInDer. headS ARe genEralLY nUmbered fRom the TOp Of The drivE pRoceedInG doWnwArd, beGInniNg at zeRo. CylindErs arE Generally numbeREd from the outsIDe EDGe OF the PlaTter proceedIng iNWard, BegiNNiNg aT Zero. SEctorS wIThIN a cylinder are generaLlY numbeRed frOm a marker in thE disk mediuM PROceeding EithER cLOckwise or countEr-cloCkwise, depeNDing on thE direCtion of dIsk rotatiON In the disK drIve, And BegINNiNg at one. A triplET SpecIfYing the HeaD number, CylIndEr nUmbEr, And sector Number in ThIs MaNnEr iS knowN As a "physiCaL seCtOr aDdresS." for insTance, The sEcToR LabEled as 16 iN fIg. 1 COuld HaVe A phySicAl SectoR addREss Of (head zEro, cylindEr sEVen, sEcToR two), or mOre concisely, a PhYsical addrEsS of (0, 7, 2). the terMS "Address" aNd "pointer" are used interchANgeably HerEin.
AlTernAtively, a gIveN sectoR maY Be idenTified By a "loGiCal SECtor aDDReSs." EAcH logical seCTOr aDdresS iS a siNgle numBer rather than a tripLEt oF numbers. The loGicAl adDREsS of A SeCTor CoRResPONds to the number oF sectors beTwEEn The addressED seCtOr and thE "first" sEctor ON the disK 10 along somE specifieD pAth wHICh tRaverses alL availabLe sectors IN ordeR. thE firsT seCtor, knOwN as "SectoR zero," iS OftEn locAted at A pHysicaL sectOr Address oF (0, 0, 1). One common traversal path Begins At logIcaL sector zeRo, tRAveRses the seCtorS in cylindeR zeRo oF head ZerO, TraveRses THe SecTOrs of CyliNDer zero of HEaD onE, PRoCeeds thus thROUGh cYlindEr zERo on eaCh suCcessive head, proceEDs to
 side 20 of the disk 10 is  accessedby ahea d 2 6moun tedon an arm 28 s e cure d to the drive 12. Toacces sd iffe r en t cyl inderso ft h e d is k10,  t h earm 2 8 m oves th e head 26into ward the cen t er  of the di sk10 or out to war d thepe rip h ery o f t he di sk 10a ccordi ng to the  p o sition of thed e si redcylinder. To acce s sd ifferent secto rs wit hi n  a c yli nde r, the dri ve  12 r o tates t h ed i s k 1 0  around a spi ndle 30, th e reb y rota ti ngt he des iredse c tor s into adja cenc y with th e head 26. Add i tionalsidesofa d isk, in cl udi ng sid e sona ddi tional p la tt ers,mayb e a cces sed  ina sim ilar manner b y a ddit i ona l dis k dri ve h ea ds. B ecause  each  s ide of a disk i s ac cessed by  aco rre sp ondin g  diskdri vehead, t he numb e r o fh e a ds  is sometimes used  t o in dicate t he num b er  o f  sides o fthe  dis k thatarea cc essibleto the dr iv e. Forex ample,  d oub le- sided disk s areaccessed  with double-headedd rives.
A give n  s e c to r  onthe  disk 10 ma y be iden tifi e dbys pecif yingah ea d , a cylinder, and a  s ectorwithi n the cylinde r. Heads a r e generall y nu m be r ed from the to p ofthe drivep roceedin g dow nward, b eginninga t  zero. C yli nde rsare g en erally number e d  fro mthe out sid e edgeofthe  pl att er  proceedi ng inwar d,  b eg in nin g atz ero. Sec to rswi thi n a c y linder  aregene ra ll y  nu mberedf ro m a ma rk er  inthe  d isk m ediu m  pr oceedin g eitherclo c kwis eor  counte r-clockwise,de pending on  t hedirect i o n of dis k rotation in the diskd rive, a ndbegin ning  at one.A t riplet  sp e cifyin g theheadnu mbe r ,  cyli n d er  nu mb er, and se c t ornumbe rin t his man ner is known as a" phy sical sectoradd ress . "  F ori ns t anc e, the s ector labeled a s 16 in FI G. 1could have a p hy sical s ector a ddres s  of (he ad zero,cylinderse ven, s ect or two), o r more c oncisely, a phy s ic al ad dre ss of(0 , 7 , 2).  The t e rms  "add ress"an d "poi nter"  a re usedinterchangeably herein. 
Alter nativ ely , a given  se c tor  may be i dent ified by a  "l ogi cal s ect o r add ress . "Eac h  logi cals ector add r es s i s asingle numb e r rat her t han a trip letof numbers. The l o gical addressof a s ect orc orre sp onds to the nu mbe ro f  sectors  b etween theaddresse ds ector  and t he "fi rst" se c t or on the  dis k 1 0 along s ome  s p ecified  p at h  which  tra ve rses a ll ava i labl e sectors in order . The f irsts ect or, k no wn as " s ecto r zero," i s often loc ated a t aphysi cal sec to r addr ess  o f (0, 0, 1 ) . One com mon t raversa lpath  be gins a t lo g i cal s ecto rzer o, traver s e st he  s e cto rs i n cyl in derzero of h e ad zero,  tr a versesth e s e c tors o f  c y l inder zero  of  head o ne, procee d s th u st hroug h cyli nder z ero one ach  s uccessi veh e ad, proce eds to
 side_20 of_the disk 10 is_accessed by_a_head 26_mounted_on an arm_28 secured to_the drive 12. To_access different cylinders_of_the disk 10, the arm 28 moves the head 26 in toward the center_of_the disk_10_or_out toward the periphery of_the disk 10 according to_the position_of the desired cylinder. To access different sectors_within_a cylinder, the_drive 12 rotates the disk 10 around a spindle_30, thereby rotating the desired sectors_into adjacency with_the_head_26. Additional sides of_a disk, including sides on additional_platters, may be accessed in a_similar manner by additional disk drive heads._Because each side of a disk_is accessed by a corresponding_disk drive_head, the number of heads_is sometimes used_to indicate_the number of_sides of the disk that are_accessible to the_drive. For example, double-sided disks are_accessed_with double-headed drives.
A_given_sector_on the_disk 10 may_be_identified by_specifying_a head, a cylinder, and a_sector_within the cylinder. Heads are generally numbered_from the top of_the_drive proceeding downward, beginning_at zero. Cylinders are generally_numbered from the outside edge of_the platter_proceeding inward,_beginning at zero. Sectors within a cylinder are generally numbered from_a marker in the disk medium_proceeding either clockwise or_counter-clockwise, depending_on_the direction of_disk_rotation in_the disk drive, and beginning at one._A triplet_specifying the head number, cylinder number,_and sector number in_this_manner is known as a "physical_sector address." For instance, the sector_labeled as 16 in FIG._1_could_have a physical sector address_of (head zero, cylinder seven, sector_two), or more_concisely, a physical address of (0, 7,_2)._The terms "address" and "pointer" are_used_interchangeably herein.
Alternatively, a given sector may_be_identified_by a "logical sector address."_Each logical sector address is a_single number rather than a triplet of numbers. The_logical address of_a sector corresponds to the_number_of_sectors between the addressed sector and the "first" sector on_the disk_10 along some_specified path which traverses all available sectors in order. The_first sector, known as "sector zero," is_often located at a physical sector address of (0, 0, 1)._One common traversal path begins at logical sector_zero, traverses the sectors in cylinder zero_of head zero, traverses_the_sectors of cylinder zero of head one,_proceeds_thus_through_cylinder zero on_each successive head,_proceeds to