 concentric data tracks and a "head" which generally comprises a "slider" that carries a read transducer and a write transducer. The drive has "servo" information recorded on this disk or on another disk to determine the position of the head. The most popular form of servo is called "embedded servo" wherein the servo information is written on the disk in a plurality of servo sectors or "wedges" that are interspersed between data regions. Data is conventionally written in the data regions in a plurality of discrete data sectors. Each data regions is preceded by a servo wedge. Each servo wedge generally comprises a servo header (HDR) containing a track identification (TKID) field and a wedge number (W#) field, followed by at least two angularly successive servo burst regions that define a plurality of burst pair centerlines. Each servo burst is conventionally formed from a series of magnetic transitions defined by an alternating pattern of magnetic domains. The servo control system samples the servo bursts with the read transducer to align the transducer with or relative to a burst pair centerline and, therefore, with or relative to a particular data track.
The servo control system moves the transducer toward a desired track during a "seek" mode using the TKID field as a control input. Once the transducer head is generally over the desired track, the servo control system uses the servo bursts to keep the transducer head over that track in a "track follow" mode. The transducer reads the servo bursts to produce a position error signal (PES). The PES has a particular value when the transducer is at a particular radial position relative to a burst pair centerline defined by the bursts and, therefore, relative to the data track center. The desired track following position may or may not be at the burst pair centerline or data track center.
The width of the write transducer is desirably narrower than the data track pitch. The servo information is recorded, therefore, to define a data track pitch that is slightly wider than the write transducer to provide room for tracking error. The servo information is usually recorded to define a data track pitch that is about 25% wider than the nominal width of the write transducer and conversely, therefore, the nominal write transducer is about 85% of the track pitch. The percentage is not exactly 85% for every transducer, however, since the width of the write transducer will vary from nominal due to typical manufacturing distributions.
FIGS. 1A and 3A show disks 12 having a plurality of servo wedges 211 comprising servo sectors 511 disposed
concentric data tracks and a " head " which generally constitute a " skidder " that carries a read transducer and a write transducer. The drive has " servo " data recorded on this disk or on another disk to specify the position of the head. The about democratic form of servo is called " embed servo " wherein the servo information is written on the disk in a battalion of servo sectors or " wedges " that are intersperse between data regions. datum is conventionally written in the data regions in a battalion of discrete data sectors. Each data regions is preceded by a servo bomber. Each servo wedge generally comprises a servo header (HDR) containing a racetrack identification (TKID) field and a wedge number (W #) field, followed by at least two angularly successive servo burst regions that define a plurality of burst pair centerlines. Each servo burst is conventionally formed from a serial of charismatic transitions defined by an alternating design of magnetic domains. The servo control arrangement samples the servo bursts with the read transducer to align the transducer with or relative to a burst pair centerline and, consequently, with or relative to a particular data track. 
 The servo control system moves the transducer toward a desired track during a " seek " mode using the TKID field as a restraint input. Once the transducer drumhead is generally over the desired track, the servo control system practice the servo bursts to keep the transducer head over that track in a " track follow " mode. The transducer reads the servo bursts to grow a position erroneousness signal (PES). The PES has a particular value when the transducer is at a especial radial position proportional to a burst pair centerline defined by the bursts and, therefore, proportional to the data track center. The desire cut following position may or may not be at the burst pair centerline or data track center. 
 The width of the write transducer is desirably narrower than the data track sales talk. The servo information is recorded, consequently, to define a data track pitch that is slightly wider than the write transducer to provide room for chase error. The servo information is usually recorded to define a data track sales talk that is approximately 25% broad than the nominal width of the write transducer and conversely, therefore, the nominal write transducer is about 85% of the track sales talk. The percentage is not exactly 85% for every transducer, however, since the width of the write transducer will vary from nominative due to typical fabrication distributions. 
 FIGS. 1A and 3A show disks 12 having a plurality of servo wedges 211 comprising servo sectors 511 disposed
 cojcentric data tracks and a "head" which ggnwrally comprjses a "suider" that carries a read trensdycer qnd a write transducer. The drivv has "serco" iiformation recorvsd on tmns dian or in another disl to deterkine the posithov lf the head. The most popular form os servo id called "embedqed xqrvo" wherein the servo information is sritten on the disk on a plurality of servo seftord or "wedges" that age interspetaed vetween data regions. Data is convehtionally written in the data rdgionx in a plutcoitj of discretx data sectors. Eacm data segions is preceded bn a sxrvo wedge. Each servo wedje generally comprisgs a servo hzader (HDR) containing q rrack idettifkxatkon (TLIS) fielf aid a wedge humber (W#) fiwld, followed by at kewwt two anguladly suscqssive servo burst regions that define d pmurality of burst pair xenterlines. Each servl burst if conventionally formed from a series of magnetic tranaktiinf eevined by an alternating pattern of magnetic djjaonx. The servo coktrol system samplrs tng servo bursts with cge read transducer tl align the rransducew wiyh or relative to a burst pqir centerliue qnd, therefore, with or relativz to a partocular data track.
The sexvo cohtrol systel moves tgd transducer towxrd a desired track during a "seqk" mode uwing the TKKD foeld af a controp inpmd. Once the transdufer hgad is generally over the desired track, the sertp control syxtam lses the fervo bursts to keqp the transdueer head over that traci in a "vrack follow" mode. The tratdducer reads the serdo byrstw to pruauce a positiom error spgual (PES). Tye PES has a partigular balue when the cxabsducer is at a paftisupac radydl position selagivd to a burst kcir zentrrline defined by tha budsts and, therefore, rclative ti the daea track centrr. The desired trafk fonloxing ppsijion may or may not be at the bhrst pair cekterline or dwta brach center.
Thz width of the write transducer is desirebly narrower than the eata track pitch. Thg strvo informatmon is recorded, therefore, to define a data track pitgh that is slightly wiser thdn thf write transducer to provide room for tracking error. The servo informatiin is nstally recorsed yo dexiue c data eracn pitch that is anout 25% wider than the nominal wivth of the wxite transducer and converselu, gherefore, the nominal write transduced is aboit 85% of the track pitch. The percrntage is not exactly 85% fpr every tranaducer, howxver, since the width of thz writw transeucev will vary frum molinal due to uypieal manufacturing distributions.
FITS. 1A abd 3A show disks 12 heving a plurwuity kf serdo wedges 211 comprjsinf servu sectors 511 dixposed
concentric data tracks and a "head" which a that carries read transducer and has information recorded on disk or on disk to determine the position of head. The most popular form of servo is called "embedded servo" wherein the information is written on the disk in a plurality of servo sectors or that interspersed data Data is conventionally written in the data regions in a plurality of discrete data sectors. Each regions is preceded by a servo wedge. Each wedge generally comprises a header (HDR) containing a track (TKID) and a number field, by at least angularly successive servo burst regions that define a plurality of burst pair centerlines. Each servo burst is formed from of magnetic defined an pattern of magnetic servo control system samples the servo read transducer to align the transducer with or to a pair centerline and, therefore, with or to a particular data track. The servo control moves the transducer toward a desired track during a "seek" mode using the TKID field control input. Once the head is generally the track, servo system uses servo bursts to keep the transducer head over that track in "track follow" mode. The transducer reads the servo bursts to position signal (PES). The has a particular value the is at a particular relative a defined the and, therefore, relative to data track center. The desired following position may or burst pair centerline or data track center. The of the write transducer is desirably narrower the data track pitch. The servo information is recorded, therefore, to define data track is slightly wider than the write transducer to room for tracking error. servo information is usually recorded to define a data pitch is about wider than the width of the transducer and conversely, nominal write is 85% pitch. The percentage is not exactly for transducer, however, since the width the will vary from nominal due to typical manufacturing distributions. FIGS. 1A and 3A show disks a plurality of servo 211 servo sectors 511 disposed
 concentric data tracks and a "hEad" which geNeralLy cOmpRiSes a "SlidEr" that carries a REad tRansducer and a write tranSduceR. THE driVE hAs "serVo" inforMAtION reCoRdEd oN tHIs Disk oR on Another Disk to deteRmiNe The position oF ThE head. The moSt pOpular form of SerVo is caLlEd "eMBeddeD seRvo" whErein tHE servo InformatiOn IS writtEN on the dISK iN a plUrality of servo secTOrS Or "wedges" that arE interSpERsED BetWeeN data regioNs. data iS ConventIOnALLY wrITten in the data Regions in a pLUraLity of DiScrETe data SectoRs. eAch Data regions Is prEceded by a Servo wEDge. Each SErvo wedGe geneRalLy cOmprISeS a SerVo HEadER (HdR) cONtaIning a trAcK iDentiFicaTION (tKID) FieLd anD a wedGe number (W#) fielD, foLlowED by At leaSt two AnguLaRly suCcessiVe serVo Burst regions thaT defIne a pluraLitY oF buRsT pair CEnterlIneS. EaCh servo Burst is COnvEnTIONaLly formed from a seriEs OF MaGnetic trAnsitiONs DeFIned by an AlTerNatiNG PatteRn of MAgNetic domAins. ThE SeRvO controL sYstem sAmPleS thE servO BursTs with The read tRansdUCer to align the tRAnsducer with oR ReLATiVE to a BurSt pair centeRlinE And, tHereFOrE, wiTH or reLativE tO A pARticular data track.
ThE sErvo coNtrol System moves thE transduceR TOWard a desIred TRaCK during a "seek" moDe usiNg the TKID fIEld as a coNtrol Input. OncE the transDUCer head iS geNerAllY ovER ThE desired track, THE serVo Control SysTem uses The SerVo bUrsTs To keep the TransducEr HeAd OvEr tHat trACk in a "traCk FolLoW" moDe. The TRansduCer reAds tHe SeRVo bUrsts to PRoDUCe a pOsItIon eRroR sIgnal (pES). THE PEs has a paRticular vAluE When ThE tRansducEr is at a particUlAr radial poSiTioN relatIVE to a bursT pair centerline defined bY The bursTs aNd, theRefoRe, relativE to The datA trACk centEr. The dEsireD tRacK FOllowING pOsiTiOn may or may NOT be At the BuRst pAir centErline or data track cENteR.
The width of thE wrIte tRANsDucER iS DesIrABly NARrower than the daTa track pitCh. tHe Servo inforMAtiOn Is recorDed, therEfore, TO define A data tracK pitch thaT iS sliGHTly Wider than tHe write tRansducer TO provIDe Room fOr tRackinG eRroR. The sErvo inFOrmAtion Is usuaLlY recorDed to DeFine a datA track pitch that is about 25% wIder thAn the NomInal width Of tHE wrIte transdUcer And conversEly, TheReforE, thE NominAl wrITe TraNSduceR is aBOut 85% of the tRAcK piTCH. THe percentagE IS Not ExactLy 85% fOR every TranSducer, however, sincE The width of the wRite TRAnsDucER wilL vAry from nominal Due To TYPical manUfActuring disTributioNs.
fiGS. 1A aNd 3A shoW disks 12 Having a PLUrALity of ServO weDges 211 comprIsiNg SErvo secToRs 511 DIsposeD
 concentric data tracks an d a "head"  whic h g ene ra llycomp rises a "slide r " th at carries a read tran sduce ra nd a wr ite t ransduc e r. T hedr iv e h as "s ervo"  in formati on recorde d o nthis disk or on  another d isk  to determin e t he pos it ion of th e h ead.The mo s t popu lar formof servoi s calle d "e mbed ded servo" wherei n  t h e servo inform ationis wr i t ten  on  the diskin  a pl u ralityo fs e r vos ectors or "we dges" thata reinters pe rse d  betwe en da ta reg ions. Datais c onvention ally w r itten i n  the da ta reg ion s i n ap lu ra lit yo f d i sc ret e  da ta secto rs .Eachdata r e g ions  is  pre ceded  by a servo w edg e. E a chservo  wedg e ge ne rally  compr isesaservo header (H DR)containin g a  t rac kident i ficati on(TK ID) fie ld anda  we dg e n um ber (W#) field, fo ll o w ed  by at l east t w oan g ularly s uc ces sive s ervoburs t  r egions t hat de f in ea plura li ty ofbu rst  pa ir ce n terl ines.Each ser vo bu r st is conventi o nally formedf ro m as erie s o f magnetictran s itio ns d e fi ned by an  alte rn a ti n g pattern of magnet ic  domai ns. T he servo cont rol system s a mples th e se r vo bursts with th e rea d transduc e r to ali gn th e transd ucer with o r relati vetoa b urs t pa ir centerline a nd,th erefore , w ith orrel ati vetoaparticula r data t ra ck .Th e s ervoc ontrol s ys tem  m ove s the transd ucertowa rd  a des ired tr a ck d urin ga"see k"mo de us ingt heTKID fi eld as acon t rolin pu t. Once  the transduc er  head is g en era lly ov e r  the des ired track, the servo c o ntrol s yst em us es t he servobur sts to  ke e p thetransd ucerhe ado v er th a t  t rac kin a "trac k fol low"mo de.The tra nsducer reads thes erv o bursts to p rod ucea po sit i on err or sig n a l (PES). The PE S has a pa rt i cu lar valuew hen  t he tran sduceris at a parti cular rad ial posit io n re l a tiv e to a bur st paircenterlin e  defi n ed  by t hebursts  a nd,  ther efore, rel ative  to th edata t rackce nter. Th e desired track followi ng pos ition  ma y or maynot beat the bu rstpair cente rli neor da tat rackcent e r. 
Th e  widt h of the write tr ans d u ce r is desira b l y  na rrowe r t h an the  dat a track pitch. Th e  servo informa tion i s r eco r ded,  t herefore, to d efi ne a  data tr ac k pitch tha t is sli gh t ly wi der th an the  writet r an s ducerto p rov ide roomfor  t r ackinger ro r . Theserv oinform ationi s us u a lly recorded todefin e a dat a  tr ack p it ch that is a bout 25% w ider than t he nom inal  widt h of th ewritetra ns ducer andc onversely , the refore,  t he n omi nal wr itet r ansdu ceris  ab out 85% o f th e  t ra c k p itch . The  p erce ntage isn ot exact ly8 5% forev ery t ransdu c er , however, s inc e the w idth of th e  wri t et ransd ucer w ill va ry from nom in al duetot y pical man ufacturin g  di st ribu tions.
F IG S. 1 Aand  3 A show disks 12  havinga plural i t y of s erv o  wed g es 211  c omprising se rvo s ec t ors 511 d isp osed
 concentric_data tracks_and a "head" which_generally comprises_a_"slider" that_carries_a read transducer_and a write_transducer. The drive has_"servo" information recorded_on_this disk or on another disk to determine the position of the head. The_most_popular form_of_servo_is called "embedded servo" wherein_the servo information is written_on the_disk in a plurality of servo sectors or_"wedges"_that are interspersed_between data regions. Data is conventionally written in the_data regions in a plurality of_discrete data sectors._Each_data_regions is preceded by_a servo wedge. Each servo wedge_generally comprises a servo header (HDR)_containing a track identification (TKID) field and_a wedge number (W#) field, followed_by at least two angularly_successive servo_burst regions that define a_plurality of burst_pair centerlines._Each servo burst_is conventionally formed from a series_of magnetic transitions_defined by an alternating pattern of_magnetic_domains. The servo_control_system_samples the_servo bursts with_the_read transducer_to_align the transducer with or relative_to_a burst pair centerline and, therefore, with_or relative to a_particular_data track.
The servo control_system moves the transducer toward_a desired track during a "seek"_mode using_the TKID_field as a control input. Once the transducer head is generally_over the desired track, the servo_control system uses the_servo bursts_to_keep the transducer_head_over that_track in a "track follow" mode. The_transducer reads_the servo bursts to produce a_position error signal (PES)._The_PES has a particular value when_the transducer is at a particular_radial position relative to a_burst_pair_centerline defined by the bursts_and, therefore, relative to the data_track center. The_desired track following position may or may_not_be at the burst pair centerline_or_data track center.
The width of the_write_transducer_is desirably narrower than the_data track pitch. The servo information_is recorded, therefore, to define a data track pitch_that is slightly_wider than the write transducer_to_provide_room for tracking error. The servo information is usually recorded_to define_a data track_pitch that is about 25% wider than the nominal width_of the write transducer and conversely, therefore,_the nominal write transducer is about 85% of the track pitch._The percentage is not exactly 85% for every_transducer, however, since the width of the_write transducer will vary_from_nominal due to typical manufacturing distributions.
FIGS. 1A_and_3A_show_disks 12 having_a plurality of_servo wedges 211_comprising servo_sectors 511 disposed