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.RR --!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--! .PL 65 .LM 1 .RM 70 .MT5 .MB6 .HM3 .FM3 .PO8 .CW10 .SR2 .RR--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!--!R .UJ0 .OJ0 .UL1 .heCD-ROM Read Sub-Channel Command Revision X3T9.2/89-095 (Rev 1) .fo 17 July 1989 - # - LASE╥ MAGNETI├ STORAG┼ MEMO INTERNATIONAL _______________________________________________________________________ Optica∞ Storagσ Division 1╖ Jul∙ 1989 To║ SCS╔ Standard≤ Committeσ X3T9.2 From║ Pau∞ Boulay (719⌐ 59│-432│ Subject║ C─-RO═ ReaΣ SuΓ-channe∞ CommanΣ Revision .lm6 áááááRevisioε Note║ Rev« ░ oµ thi≤ documen⌠ wa≤ handeΣ ou⌠ a⌠ thσ ì áááááChicag∩ workinτ grou≡ meetinτ (Jul∙ 1░ anΣ 11)« Rev« ▒ ì áááááincorporate≤ thσ result≤ oµ tha⌠ discussion« I⌠ additionall∙ ì áááááprovide≤ thσ definitioε oµ thσ ne≈ Scaε fo≥ SuΓ-channe∞ Datß ì ááááácommand« Thσ alternativσ ▒ change≤ t∩ thσ ReaΣ SuΓ-channe∞ ì ááááácommanΣ no≈ reflec⌠ thσ existencσ oµ thσ Scaε fo≥ SuΓ-channe∞ ì áááááDatß command. .lm1 Sooε afte≥ thσ Junσ meeting¼ representative≤ froφ Son∙ Corporatioε ì contacteΣ mσ witΦ ß proposa∞ fo≥ ß changσ iε thσ C─-RO═ commanΣ se⌠ ì ReaΣ SuΓ-channe∞ command« Thσ probleφ tha⌠ the∙ discovereΣ involve≤ ì returninτ thσ Mediß Cataloτ Numbe≥ » Universa∞ Produc⌠ Codσ (MCN/UPC⌐ ì anΣ Internationa∞ StandarΣ recordinτ Codσ (ISRC⌐ fields« WitΦ thσ ì definitioε iε thσ curren⌠ SCS╔-▓ draf⌠ user≤ wil∞ finΣ retrievinτ thi≤ ì datß mos⌠ inconvenient¼ bu⌠ no⌠ impossible. Thi≤ documen⌠ i≤ thσ resul⌠ oµ m∙ rσ-revie≈ oµ thσ commanΣ anΣ thσ ì implementatioε implication≤ oµ it≤ curren⌠ definitioε (anΣ lacδ ì thereof)« I⌠ cover≤ somσ oµ thσ samσ point≤ tha⌠ Son∙ raise≤ bu⌠ froφ ì perhap≤ ß differen⌠ viewpoint« ╔ d∩ no⌠ purpor⌠ t∩ speaδ fo≥ Son∙ ì corporatioε ¡ o≥ fo≥ N.V« Philip≤ fo≥ tha⌠ matter« I'φ jus⌠ ß SCS╔-▓ ì sectioε edito≥ ¡¡ madσ ß bi⌠ morσ humblσ b∙ recognizinτ tha⌠ thi≤ ì wholσ mes≤ slippeΣ b∙ mσ iε thσ firs⌠ place. ╔ seσ threσ options: 1⌐ AdΣ ß fe≈ carefull∙ wordeΣ change≤ t∩ thσ definition≤ anΣ ì implementor≤ note≤ t∩ suppor⌠ thi≤ requiremen⌠ withiε thσ frameworδ oµ ì thσ presen⌠ command« Thσ inten⌠ i≤ t∩ changσ thσ characte≥ oµ thσ ì commanΣ froφ onσ tha⌠ return≤ informatioε froφ thσ curren⌠ secto≥ t∩ ì onσ whicΦ return≤ thσ curren⌠ se⌠ oµ information« Thσ resul⌠ coulΣ bσ ì workable« Therσ arσ somσ implementatioε consideration≤ tha⌠ ╔ vie≈ a≤ ì mino≥ bu⌠ whicΦ other≤ migh⌠ not« Afte≥ all¼ thi≤ i≤ aε optiona∞ ì command« Thσ change≤ requireΣ arσ consisten⌠ witΦ tha⌠ whicΦ i≤ ì alread∙ iε thσ commanΣ. 2⌐ AdΣ aε optioε t∩ thσ commanΣ s∩ ß use≥ caε turε thi≤ int∩ aε activσ ì commanΣ whicΦ scan≤ ß portioε oµ thσ mediß t∩ eithe≥ finΣ ß ì specificall∙ requesteΣ suΓ-channe∞ datß typσ o≥ sho≈ tha⌠ i⌠ i≤ no⌠ ìèpresent« Thσ use≥ mus⌠ stil∞ follo≈ certaiε procedure≤ t∩ ge⌠ al∞ thσ ì suΓ-channe∞ datß tha⌠ i≤ present« Thi≤ optioε involve≤ ß technica∞ ì changσ t∩ thσ standarΣ anΣ thσ risδ tha⌠ wσ haven'⌠ though⌠ oµ al∞ thσ ì implications« (Thi≤ i≤ thσ approacΦ takeε iε thσ Son∙ proposal.) 3⌐ Creatσ ß ne≈ Scaε fo≥ SuΓ-channe∞ Datß command« Thi≤ woulΣ bσ aε ì activσ commanΣ witΦ ß startinτ LB┴ anΣ ß transfe≥ lengtΦ denominateΣ ì iε logica∞ blocks« Thi≤ commanΣ woulΣ scaε ß portioε oµ thσ mediß t∩ ì eithe≥ finΣ suΓ-channe∞ datß o≥ repor⌠ tha⌠ i⌠ i≤ no⌠ present« Thi≤ ì optioε als∩ involve≤ ß technica∞ changσ t∩ thσ standarΣ witΦ thσ ì attendan⌠ risks« Iε spitσ oµ al∞ that¼ thσ usσ oµ ßε activσ commanΣ i≤ ì thσ cleanes⌠ wa∙ fo≥ ß use≥ t∩ acces≤ thσ datß iε thσ MCN/UP├ anΣ ISR├ ì fields« A⌠ Chicago¼ wσ concludeΣ tha⌠ al∞ oµ thesσ alternative≤ represent ß ì substantivσ change« Wσ als∩ concludeΣ tha⌠ thσ mos⌠ correc⌠ technica∞ ì solutioε i≤ t∩ incorporatσ part≤ oµ alternativσ ▒ plu≤ alternativσ 3« Thσ reaΣ suΓ-channe∞ commanΣ coulΣ bσ limiteΣ t∩ tw∩ case≤ (1) durinτ ì aε audi∩ pla∙ operatioε anΣ (2⌐ afte≥ ß scaε fo≥ suΓ-channe∞ datß ì command. ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡- SuΓ-Channe∞ Data A≤ witΦ mos⌠ C─-RO═ specifiπ problems¼ thi≤ onσ ha≤ it≤ root≤ iε thσ ì C─ Audi∩ format« (C─ Audi∩ i≤ thσ basi≤ fo≥ thσ C─-RO═ format.⌐ Thσ ì datß tha⌠ thσ ReaΣ SuΓ-channe∞ commanΣ retrieve≤ come≤ froφ onσ oµ ╕ ì lo≈ ratσ timσ multiplexeΣ datß stream≤ whicΦ sharσ spacσ witΦ thσ ì highe≥ ratσ datß o≥ audi∩ datß stream« Onσ oµ these¼ thσ ╤ suΓ-ì channel¼ encode≤ thσ informatioε tha⌠ thσ ReaΣ SuΓ-channe∞ commanΣ ì returns« Onσ ╤ suΓ-channe∞ framσ i≤ encodeΣ pe≥ datß secto≥ (204╕ ì byte≤ plu≤ ECC¼ etc.⌐ o≥ audi∩ framσ (1/75tΦ seconΣ a⌠ standarΣ rate)« ì Fo≥ a⌠ leas⌠ ╣ ou⌠ oµ an∙ 1░ frame≤ thσ ╤ suΓ-channe∞ encode≤ absolutσ ì anΣ relativσ locatioε information« Thσ remaininτ ▒ oµ an∙ 1░ frame≤ ì ma∙ optionall∙ contaiε MCN/UP├ o≥ ISR├ data« Iµ aε optiona∞ datß iteφ ì i≤ present¼ i⌠ mus⌠ appea≥ iε a⌠ leas⌠ ▒ oµ an∙ 10░ frames« Neither¼ ì eithe≥ o≥ botΦ ma∙ bσ present« Probleφ ▒ ¡ Definitioε oµ curren⌠ secto≥ i≤ to∩ loose. Thσ presentl∙ defineΣ ReaΣ SuΓ-channe∞ commanΣ caε usuall∙ operatσ iε ì ß passivσ way« I⌠ simpl∙ return≤ thσ datß froφ thσ curren⌠ sector« Iµ ì therσ i≤ aε oε-goinτ (background⌐ audi∩ operatioε tha⌠ i≤ easy« Iµ thσ ì curren⌠ statσ oµ thσ C─-RO═ drivσ i≤ audi∩ pause¼ therσ i≤ usuall∙ ì littlσ difficult∙ iε implementinτ thσ command« However¼ therσ ma∙ bσ ì somσ implementatioε dependen⌠ ambiguit∙ iε exactl∙ whicΦ i≤ thσ ì curren⌠ sector« Iµ curren⌠ secto≥ i≤ defineΣ t∩ meaε ¡¡ thσ secto≥ a⌠ ì whicΦ thσ pauseΣ audi∩ operatioε wil∞ resumσ ¡¡ thi≤ commanΣ ma∙ takσ ìèß ful∞ rotatioε t∩ returε data« Thσ othe≥ possibilit∙ i≤ t∩ takσ ß ì loose≥ interpretatioε oµ curren⌠ secto≥ ¡¡ thσ secto≥ no≈ slidinτ ì unde≥ thσ reaΣ heaΣ ¡¡ anΣ returε thσ datß fo≥ tha⌠ one« Thi≤ result≤ ì iε minima∞ delay« Thσ curren⌠ secto≥ i≤ simpl∙ no⌠ defineΣ betweeε operations¼ sa∙ ì betweeε ReaΣ commands« Thσ natura∞ interpretation≤ arσ thσ samσ tw∩ a≤ ì durinτ thσ pausσ state« Thσ ¡¡ secto≥ a⌠ whicΦ thσ operatioε wil∞ bσ ì resumeΣ ¡¡ definitioε i≤ ß littlσ stick∙ when¼ fo≥ instancσ, thσ ì logica∞ blocδ sizσ i≤ les≤ thaε thσ secto≥ sizσ anΣ thσ las⌠ ReaΣ ì commanΣ completeΣ somewherσ iε thσ middlσ oµ ß sector« I⌠ caε als∩ bσ ì problematica∞ when¼ fo≥ instance¼ thσ previou≤ commanΣ endeΣ a⌠ thσ ì las⌠ secto≥ oµ ß track« Thσ loose≥ definitioε ¡¡ thσ secto≥ no≈ ì slidinτ unde≥ thσ reaΣ heaΣ ¡¡ i≤ easie≥ anΣ quicke≥ t∩ implemen⌠ ì becausσ thσ operatioε i≤ exactl∙ thσ samσ a≤ ß ReaΣ SuΓ-channe∞ durinτ ì ß backgrounΣ audi∩ operation« However¼ thi≤ ma∙ leaΣ t∩ inconsisten⌠ ì result≤ wheε thσ se⌠ oµ sector≤ beinτ reaΣ iε thi≤ holΣ positioε ì opera⌠ioε include≤ sector≤ froφ ⌠w∩ differen⌠ tracks. Probleφ ▓ ¡ MCN/ISR├ anΣ ISR├ datß caε bσ harΣ t∩ obtain« Thσ ReaΣ SuΓ-channe∞ commanΣ no≈ return≤ datß froφ thσ curren⌠ sector« ì Thσ ISR├ anΣ MCN/UP├ datß item≤ caε bσ ver∙ difficul⌠ t∩ obtaiε ì becausσ the∙ ma∙ appea≥ iε a≤ fe≈ a≤ ▒ pe≥ 10░ sectors« Whilσ playinτ ì audi∩ a≤ ß backgrounΣ proces≤ (immediatσ bi⌠ set⌐ i⌠ i≤ probabl∙ ì reasonablσ t∩ issuσ ß ReaΣ SuΓ-channe∞ commanΣ durinτ 10░ successivσ ì blocks« (Ratσ oµ 13.│ m╙ o≥ les≤ pe≥ sample.⌐ However¼ wheε thσ drivσ ì i≤ iε ß pausσ statσ 2░ o≥ fewe≥ sector≤ wil∞ pas≤ unde≥ thσ reaΣ head« ì Dependinτ oε thσ definitioε oµ 'currentº adopteΣ b∙ thσ ì implementation¼ onσ o≥ an∙ oµ thesσ ma∙ bσ read« Thσ probleφ i≤ tha⌠ ì durinτ aε audi∩ pause¼ n∩ ISR├ o≥ MCN/UP├ informatioε migh⌠ bσ founΣ ì eveε thougΦ the∙ exis⌠ oε thσ curren⌠ track. Datß track≤ incu≥ additiona∞ problems« Therσ i≤ n∩ defineΣ pausσ statσ ì anΣ n∩ immediatσ typσ operatioε tha⌠ proceed≤ iε thσ background« ì Strictl∙ speaking¼ 'currentº i≤ undefineΣ betweeε datß operations« ┴ ì ReaΣ SuΓ-channe∞ commanΣ issueΣ afte≥ ß reaΣ commanΣ migh⌠ bσ expecteΣ ì t∩ behavσ likσ onσ issueΣ durinτ aε audi∩ pause¼ bu⌠ therσ i≤ n∩ ì languagσ iε thσ speπ tha⌠ guarantee≤ this« ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡- ProposeΣ solutions Optioε 1« Modif∙ definition≤ anΣ adΣ implementor≤ notes. Mos⌠ oµ thesσ difficultie≤ arisσ froφ thσ operatioε oµ thσ worΣ ì 'currentº iε thσ commanΣ definition« Certainly¼ whilσ aε audi∩ pla∙ ì progresses¼ thσ locatioε datß shoulΣ bσ u≡ t∩ date« Thesσ othe≥ suΓ-ì channe∞ datß item≤ eithe≥ d∩ no⌠ changσ (MCN/UPC⌐ o≥ onl∙ changσ a⌠ ß ì tracδ boundar∙ (ISRC)« Therefore¼ returninτ MCN/UP├ anΣ ISR├ suΓ-ì channe∞ datß need≤ t∩ mee⌠ ß mucΦ loose≥ currenc∙ requirement« Thσ ì datß mus⌠ bσ correc⌠ fo≥ thσ areß oµ thσ mediß tha⌠ contain≤ thσ ìècurren⌠ sector¼ i⌠ neeΣ no⌠ actuall∙ bσ froφ thσ curren⌠ sector« Thσ proposeΣ interpretatioε oµ ReaΣ SuΓ-channe∞ a≤ applieΣ t∩ thesσ ì particula≥ field≤ i≤ t∩ suppl∙ informatioε froφ thσ las⌠ appropriatσ ì secto≥ encountered« B∙ appropriate¼ ╔ meaε froφ thσ las⌠ secto≥ tha⌠ ì haΣ tha⌠ typσ oµ datß oε thσ tracδ reporteΣ iε thσ locatioε par⌠ oµ ì thσ data« (Thi≤ need≤ t∩ bσ donσ fo≥ thσ ISR├ field¼ thσ tracδ ì dependenc∙ doe≤ no⌠ appl∙ t∩ thσ MCN/UP├ field.⌐ Thσ implementatioε ì implicatioε i≤ tha⌠ thσ drivσ o≥ controlle≥ tha⌠ support≤ thi≤ featurσ ì need≤ t∩ kee≡ aε updateΣ cop∙ oµ thesσ suΓ-channe∞ datß item≤ a≤ the∙ ì arσ encountered« (Fo≥ thσ ISR├ fielΣ i⌠ woulΣ als∩ havσ t∩ kee≡ ß ì tracδ numbe≥ taτ t∩ bσ ablσ t∩ tel∞ iµ thi≤ cop∙ stil∞ applie≤ t∩ thσ ì curren⌠ track.⌐ ¡¡ Immediatel∙ followinτ Tablσ 1│-17¼ deletσ 'currentº froφ thσ ì commanΣ definition« AdΣ Implementor≤ note« Thi≤ rewordinτ als∩ get≤ ì riΣ oµ thσ implicatioε tha⌠ thi≤ commanΣ i≤ onl∙ valiΣ durinτ ß ì backgrounΣ audi∩ pla∙ operation. "Thσ REA─ SU┬-CHANNE╠ commanΣ (Tablσ 1│-17⌐ request≤ tha⌠ thσ targe⌠ ì returε requesteΣ suΓ-channe∞ datß plu≤ thσ statσ oµ audi∩ pla∙ ì operation≤ a≤ appropriate« Thi≤ commanΣ shal∞ returε thσ suΓ-channe∞ ì datß reaΣ durinτ aε oε-goinτ audi∩ pla∙ operatioε o≥ thσ datß reaΣ b∙ ì ß previou≤ SCA╬ FO╥ SUB-CHANNE╠ DA╘A command« .lm 3 áá"IMPLEMENTOR╙ NOTE║ SuΓ-channe∞ datß returneΣ b∙ thi≤ commanΣ ma∙ ì áábσ froφ thσ las⌠ appropriatσ secto≥ encountereΣ b∙ ß Pla∙ Audi∩ o≥ ì ááScaε fo≥ SuΓ-channe∞ Datß command« Thσ targe⌠ i≤ responsiblσ tha⌠ ì ááthσ datß returneΣ arσ consistent« Fo≥ example¼ thσ Internationa∞ ì ááStandarΣ Recordinτ Codσ (ISRC⌐ datß reporteΣ mus⌠ havσ beeε reaΣ ì ááfroφ thσ samσ tracδ a≤ thσ reporteΣ curren⌠ positioε data." .lφ 1 ¡-Replacσ thσ 3rΣ paragrapΦ followinτ Tablσ 1│-1╣ (countinτ thσ ì implementer≤ note)« Makσ ß distinctioε betweeε thσ locatioε ì informatioε anΣ thσ othe≥ suΓ-channe∞ stuff« Permi⌠ reportinτ MCN/UP├ ì anΣ ISR├ datß froφ ß previou≤ appropriatσ block« Definσ current ì fo≥ thσ severa∞ possiblσ cases« "Thσ suΓ-channe∞ datß blocδ consist≤ oµ contro∞ datß (byte≤ ┤-5)¼ ì curren⌠ positioε datß (byte≤ ╢ ¡ 15⌐ anΣ identificatioε datß (byte≤ 1╢ ì ¡ 47)« Thσ contro∞ datß anΣ curren⌠ positioε datß i≤ obtaineΣ froφ ì thσ suΓ-channe∞ ╤ informatioε oµ thσ curren⌠ block« Identificatioε ì datß ma∙ bσ reporteΣ tha⌠ wa≤ obtaineΣ froφ ß previou≤ block« Iµ ì identificatioε datß i≤ reported¼ thσ datß shal∞ bσ valiΣ fo≥ thσ ì secto≥ addresseΣ b∙ thσ curren⌠ positioε data« "(1⌐ Iµ aε audi∩ pla∙ operatioε i≤ proceedinτ iε thσ backgrounΣ o≥ i≤ ì paused¼ positioε datß fo≥ thσ las⌠ secto≥ playeΣ shal∞ bσ reported. "(2⌐ Iµ thσ las⌠ drivσ operatioε wa≤ ß Scaε fo≥ SuΓ-channe∞ Datß ì command¼ positioε datß fo≥ thσ las⌠ secto≥ scanneΣ shal∞ bσ ì reported. "(3⌐ Iε othe≥ cases¼ fo≥ instancσ afte≥ ß reaΣ o≥ ß seeδ operation¼ ì thσ targe⌠ ma∙ repor⌠ positioε datß fo≥ thσ las⌠ secto≥ processeΣ b∙ ì thσ drive." è Optioε 2« Changσ thσ commanΣ t∩ bσ aε activσ commanΣ upoε request. ¡¡ Usσ bytσ │ oµ thσ CD┬ t∩ specif∙ thσ typσ oµ datß beinτ requested« ¡¡¡ ░ request≤ thσ presen⌠ passivσ typσ operation. ¡¡¡ ▒ request≤ ß scaε fo≥ track¼ index¼ absolutσ addres≤ anΣ ì relativσ addres≤ information. ¡¡¡ ▓ request≤ ß scaε fo≥ ß MCN/UP├ field. ¡¡¡ │ request≤ ß scaε fo≥ aε ISR├ field. ¡¡¡ Othe≥ value≤ reserved. ¡¡ Thσ scaε woulΣ star⌠ wherσ thσ las⌠ operatioε lef⌠ ofµ anΣ continuσ ì a≤ needeΣ t∩ finΣ thσ requesteΣ fielΣ o≥ sho≈ tha⌠ i⌠ doe≤ no⌠ appear. .cp20 Optioε 3« Ne≈ Scaε fo≥ Sub-channe∞ Datß commanΣ« SCA╬ FO╥ SUB-CHANNE╠ DA╘A Command Tablσ 13-xx: SCA╬ FO╥ SUB-CHANNE╠ DA╘A Command ============================================================================== Bitⁿ ╖ ⁿ ╢ ⁿ ╡ ⁿ ┤ ⁿ │ ⁿ ▓ ⁿ ▒ ⁿ ░ | Bytσ ⁿ ⁿ ⁿ ⁿ ⁿ ⁿ ⁿ ⁿ | ============================================================================== ░ ⁿ Operatioε Codσ (46h⌐ | -----|-----------------------------------------------------------------------| ▒ ⁿ Logica∞ Uni⌠ Numbe≥ ⁿ ReserveΣ | -----|-----------------------------------------------------------------------| 2 ⁿ (MSB) | -----|--¡ ---| 3 ⁿ | -----|--¡ Startiετ Logica∞ Block Address ---| 4 ⁿ | -----|--¡ ---| 5 ⁿ (LSB)| -----|-----------------------------------------------------------------------| 6 ⁿ SuΓ-channe∞ Datß Type≤ | -----|-----------------------------------------------------------------------| 7 ⁿ (MSB) | -----|--¡ Transfe≥ LengtΦ ---| 8 ⁿ (LSB⌐ | -----|-----------------------------------------------------------------------| ╣ ⁿ Control | ============================================================================== .aw on .pm 3 ááThσ SCA╬ FO╥ SU┬-CHANNE╠ DAT┴ CommanΣ (Tablσ 1│-xx⌐ request≤ thatì thσ targe⌠ reaΣ suΓ-channe∞ data« SuΓ-channe∞ informatioε reaΣ b∙ ì thi≤ commanΣ ma∙ bσ transferreΣ t∩ thσ initiato≥ witΦ ß ReaΣ SuΓ-ì channe∞ command. èááThσ startinτ logica∞ blocδ addres≤ fielΣ specifie≤ thσ logica∞ blocδ ì a⌠ whicΦ thσ suΓ-channe∞ scaε shal∞ begin. ááThσ suΓ-channe∞ datß type≤ fielΣ indicates thσ suΓ-channe∞ datß ì item(s⌐ t∩ bσ locateΣ b∙ thσ scaε operation« Thσ scaε shal∞ bσ stoppeΣ ì a≤ sooε a≤ al∞ thσ requesteΣ informatioε item≤ havσ beeε read« Iµ thi≤ ì fielΣ i≤ zero¼ thσ scaε shal∞ continuσ unti∞ thσ Transfe≥ LengtΦ ì reque≤⌠ i≤ satisfied. .pm0 Tablσ 1│-yy║ SuΓ Channe∞ Datß Types ====================================================================== Code Value Datß type≤ t∩ bσ transferreΣ -----------¡ -------------------------------------------------------- 0Φ N∩ sub-channe∞ datß typσ specified 1h SuΓ-channe∞ ╤ curren⌠ positioε datß requested« (i.e« track¼ index¼ absolute address¼ relativσ address.) 2h Sub-channe∞ ╤ mediß cataloτ numbe≥ requested. 3h Sub-channe∞ ╤ curren⌠ locatioε datß anΣ mediß catalog number informatioε requested. 4Φ Sub-channe∞ ╤ ISRC requested. 5Φ Sub-channe∞ ╤ curren⌠ locatioε datß anΣ ISRC requested. 6Φ Sub-channe∞ ╤ mediß cataloτ numbe≥ anΣ ISR├ requested. 7Φ Sub-channe∞ ╤ curren⌠ locatioε datß¼ mediß cataloτ numbe≥ anΣ ISRC requested. 8Φ ¡ FFh Reserved ====================================================================== .pm 3 ááThσ transfe≥ lengtΦ fielΣ specifie≤ thσ maximuφ numbe≥ oµ logica∞ ì block≤ tha⌠ shal∞ bσ scanned« ┴ transfe≥ lengtΦ fielΣ oµ zer∩ ì indicate≤ tha⌠ n∩ suΓ-channe∞ scaε shal∞ occur« Thi≤ conditioε shal∞ ì no⌠ bσ considereΣ a≤ aε error« ááIµ thσ logica∞ blocδ lengtΦ i≤ no⌠ equa∞ t∩ thσ secto≥ sizσ thσ ì targe⌠ ma∙ adjus⌠ thσ startinτ logica∞ blocδ addres≤ anΣ thσ transfe≥ ì length« Iε sucΦ case¼ i⌠ i≤ recommendeΣ tha⌠ thσ targe⌠ star⌠ thσ scaε ì operatioε witΦ thσ beginninτ oµ ß secto≥ wheneve≥ thσ startinτ logica∞ ì addres≤ fall≤ withiε tha⌠ secto≥ (MS╞ unit)« Iµ thσ requesteΣ transfe≥ ì lengtΦ cause≤ thσ enΣ oµ a suΓ-channe∞ scaε t∩ fal∞ withiε ß secto≥, ì thσ targe⌠ ma∙ continuσ thσ scaε operatioε througΦ thσ enΣ oµ tha⌠ ì sector.