The Very Best of Atari Inside

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064020303000000128004006006000000 1PAULA 2.1 Modfile Player0 2Seite #0 F0110000001 R [.◆....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆...]0110 9[...◆.◆...◆◆..◆.....◆....◆.◆..◆....◆....◆....◆....◆....◆....◆....◆.]0110 Ç üëPAULA][ ü(Paula,taketwo!) ë ÇYetanotherAmiga-MODfile-Player fortheAtariTT&STE Version2.2a 20-Feb-93 Sharewareby PascalFellerich ëShareware: Ç Startingwithversion2.0Paulaisshareware.Thatmeansthat youmaydistributeandtestthissoftwarefreely.Butifyou useitregularlyyouhavetoregister.Unregisteredcopiesof Paulawillremindyousometimestodoso.Moreoverthese unregisteredcopieswillneverbe'better'thantheoriginal v2.0;newfeaturesaredisabled.Forthemomentthesearethe autoloadfunctionandthesupportforpackedmodules. ♪③AtthebeginningPaulawasalittleutilitytoplaymodfiles whichIwroteinsomeweeks.Asthereactionsonthislittle pieceofsoftwarewereverypositive,Idecidedtorewritethe playercompletelywhichmadeitpossibletointegratemanynew features.Paulahasbecomearealpowerfulprogramwhichhasno equivalentuntilnow.SoIdecidedtoreleaseitasshareware. You'llfinddetailsintheparagraphentitled'Registration Procedure'onpage11. ♪②Thefollowingfilesarepartofthe'PAULA'-packageandmust remainunchangedandbedistributedtogether: ê1.ÇêPAULA.APPÇ-Themainprogram(alternativenamesare PAULA.ACCorPAULA.PRG) ê2.ÇêPAULA_D.TXTÇ -thegermanmanual ê3.ÇêPAULA_E.TXTÇ -theenglishmanual ê4.Ç êMP.TTPÇ -ModPlay:alittleutilitytoplaymodules evenfromCLI's ê5.Ç êMP.CÇ -thesourcecodeofModPlay. ê6.Ç êCHECKMOD.TTPÇ -ChecksifamoduleisOKandrepairs corruptedmodfilesasfarasthisis possible. ♪②Thefile'PAULA.INF'êmustnotbegivenawayÇasthisfile containsyourregistrationdata. ♪②PaulamaybedistributedviaBBSandon'PublicDomain'disks; howeverthesharewarestatusofthissoftwareisnotaffected! ♪①AllrightsreservedbyP.Fellerich. ♪⑧ Myaddress: PascalFellerich 45,ruedesGenets L-3482Dudelange (Luxembourg) Postalchequeaccount: CCP65407-29 E-Mail: 2:270/16.3@fidonet ♪③ThelatestreleasesofPaulaareavailableinthefollowingBBS (inLuxembourg,don'tforgettherightdialingprefix)underthe nameof'PAULA2*.LZH': ♪√Ç NoNameBox #1 595243,300-14400BpsUSRDS,V.32b (Fidonet2:270/16) NoNameBox#2 596213,300-16800BpsZyX,V.32b (Fidonet2:270/14) ComNet (line1) 466893,300-14400BpsUSRDS,V.32b (line2)467516,300-14400BpsUSR,HST (line3) 222534, 9600-14400BpsUSRDS,V.32b ♪⑥ëWhyPaula? Ç Paulaplaystheso-called'modfiles'usingtheSTE/TTPCMsound chip.Thesemodfiles,alsocalled'modules',originatefromthe Amigawhichhasaspecialfour-channelPCMsoundchipcalled 'Paula'. ♪④Pauladoesn'tclaimtobetheonlyorthefastestmodplayer availablefortheAtari,butithasauniquecombinationofa perfectGEMuserinterfaceandacollectionofsuperfluous features... ♪④ëWhatdoesPaula? Ç Toavoidaratherlengthydescription,hereisashortlist withPaula'sfeatures: ♪ê1.Internal: Ç *CompatibletoreallyallMOD-formats,rangingfromtheold SoundtrackerformattothenewProtrackerformat. *Threesamplingfrequenciesareavailable:12.5,25,50KHz (whenusingPaulaonST'swithalittlehelpfromthesound- driver'PETRA'it's6,9.6and12KHz). *Linearinterpolationoptiongivingagreatimprovementin soundquality. *Boosteroption,risingtheS/Nratioby6dB. *Completelyindependentpitchandspeedtuning. *SupportsLZ5orAFXpackedmodules. ♪≈Çê2.GEM&Co-theuserinterface: Ç *RealGEM-consequentlyitwillrunonanyTOS-machine.This alsoincludesAtari'snewMultiTOS. *Simpleandintuitivecontrol *SupportsextendedselectionfeaturesofSelectric™andGemini *'Programmable'likeasimpleCDplayer *Random:randomplayofseveralmodules. ♪②*Repeat-switch:onemoduleorawholeselectionmayberepeated indefinitely *CPULoadandpositiondisplay ♪⑤ëHowitbegan... Ç WhenIgotmyTTIwantedtohearthenewsoundchip.SoI downloadedsomemodplayersfortheSTEandtriedthem. Unfortunatelymostofthemcrashed,andthosewhichranonthe 68030produced'lo-fi'(lowfidelity)sound.SoIhadtowritea playeronmyown.Butthatwaseasiersaidthandone-Ihadto acquiretheknowledgeofthe'real'PAULA-chipintheAmigaand ofcourseoftheSTE/TTsoundhardwaresimplybecauseIwanted toportanoldreplayroutinefromtheAmiga(D.O.C. replayroutine2.0fromjune1986).SomeweekslaterPaula1.0 was'upandrunning'.Thisreleasewasstillbuggyandhad limitedcapacitiesbutitfinallyworkedfineontheTT.After severaloptimizationsandimprovementsIconcludedthe developmentatv1.5. ♪③Inapril92adiscussioninthefidonetBBSre-ignitedthe globalinterestinthemoduleplayer,andIdecidedtocontinue thedevelopment.Theversions1.7and1.8werereleased.Inthe meantime,thesoundqualitywasgreatlyenhancedbutstillthe userinterfacewaslousy.SoIrewrotethewholething-that's it... ë ♪④Systemrequirements: Ç PaularunsonallTOS-basedmachine(>=TOS1.4)havingaSTE compatiblePCMsoundchip...orthesounddriverêPETRAÇ! ♪③However,onlythefastermachinesallowdecentbackgrouduseof Paula;anormalSTErunningat8MHzwon'tdo25KHzsampling frequency.AMegaSTEat16MHzisfine,aTTisbetter. TobeabletorunPaulaonST'swithoutthePCMsoundchipyou ÇneedPETRA-asounddriver(shareware,too)forPaulaby ChristianLimpach. ë ♪④Installation: Ç Paulamayrunasanaccessoryorasanapplication.Withnormal TOSversionstheaccessorymodeisuseful,underMultiTOSyou mayfinditbettertouseitasaprogram.Ofcourseyoumayuse 'theChameleon'(oranyothergoodaccessoryloader)toloadthe ACC. ♪③WhenusingMultiTOSyoumayrunPaulaasanormalprogram;but thenyoumaynotcloseit'smainwindowwithoutleavingthe program! ë ♪③ÇAnotherusefulthingisXCONTROL-youshouldhaveinstalledthe 'SOUND'cpx-modulesothatyoucanchangethevolume,treble, bassandbalance.Moreoveryoushouldconnectyourcomputerto yourstereoequipment(viatheRCAjacks)togetthebest possiblesound. ë ♪④User'sGuide: Ç AfteryouhavelaunchedPaulayougetawindowcontainingthe maindialog.Thisoneissubdividedinto6areas: 1.theinfoline 2.thePlayer&SoundSetup 3.SampleFreq 4.CPULoad 5.Position 6.theplayer'scontrolkeys ♪⑤ëThecontrolkeys Ç Thesecontrolsarehopefullythesimplest.Theycarrythe commonlyusedsymbolsyoualsofindonacassettetape recorder,soyoushouldbefamiliarwiththose.Notethatevery keyismarkedwithalittleletterintheupperleftcorner- that'sthekeyboardshortcut.Press'L'toëLÇoadafile. ♪③êLOAD:ÇFirstyoumustloadamodule.WhenyouclickontheLOAD- buttonyougetthefileselectorinordertoselectamodule.On 'OK'Paulaimmediatelyloadsthemodule.Ifthisoperationwas successfultheinfolineofthewindowwillshowthetext 'Stopped:<modfilename>'.Ifanerroroccurredyouwillbe informedbyastandardalertbox. ♪²ÇIfyouhaveinstalled'Selectric™'asafileselector,youmay alsospecifymorethanonemodule! NOTE:Paulaonlyloadsuncompressedmodules. ê ♪③ÇêSTOP:ÇWell,thisonestopsamoduleandresetstheplayer.This alsoclearsPaula'smemory-ifyouhadselectedseveralmodules Paulawillforgetthem.Theinfobarshows'Stopped:...'. Inaccessorymode,closingthewindowinthestoppedstatealso releasesthememoryallocatedforthelastloadedmodule. ♪③êPLAY:ÇStartstheplayer.Ifyouhaven'tselectedamodulePaula willpromptyoutodoso.Ifyoupress'PLAY'whenPaulaisbusy playingoneofseveralmodulesitwillskiptothenextmodule. (Skipfunction). ♪③êPAUSE:ÇStopstheplayertemporarily.Theplayerisnotreset!In thatstateyoumayalsoquittheaccessory(closethewindow) withoutlosingthecurrentmodule.Tocontinue,pressPAUSEor PLAY. ♪③êREW:Ç(REWIND)Jumpstothepreviouspositioninthemodule. ThisfunctionworksonlyifPaulaisinthe'playing'or 'paused'state. ♪②êFF:Ç(FASTFORWARD)Jumpstothenextpositioninthemodule. Thisfunctiontooonlyworksinplay-orpause-mode. ♪②ê!:Ç(Exclamationsign)InvokestheSETUP-dialogwhichoffers somemorefunctionslikepitchandspeedtuning. ♪④ê?:Ç(Questionmark)SomegeneralinformationsaboutPaula. Throughthisdialogyoualsogettheregistrationdialog.Howto registerisdescribedsomepageslater(title:Registration procedure) ♪③Trytofamiliarizeyourselfwiththesecommandsbysimplytrying themout!Whateveryoudo,youwillnotsuccedincrashing Paula-evennotonmachineswithmemoryprotection. ë ♪⑤Theinfoline Ç Paulausestheinfolineofthewindowtodisplayit'scurrent statusaswellasthetitleofthecurrentyloadedmodule. Currentlyfourstatesaredefined: ♪④êInactive:ÇPauladoesnothing.Nofileisloadedandnomemory isallocated.WhenyouchangeresolutionsPaulashould preferablybeinthismodetoavoidmemorylossorsystem crashes. ♪③êStopped:ÇPaulahasloadedamodule.Ifyouchangeresolution nowyouwilllosetheallocatedmemorybecauseyoudidn'tgive Paulaachancetoreleaseit. Ç ♪②êPaused:ÇPaulaiswaitingtocontinue.TheFFandREWbuttons work. ♪④êPlaying:ÇPaulaisbusy-don'tyouhearthat?Ifanotherprogram accessesthesoundhardwarePaulaisstopped,ofcourse.Butas soonasthesoundchipgetsfreedPaulatriestocontinue,which maytakeupto1second.Ifnot,thisisabugandshouldbe reported.Howeveryoumaymanuallyrelaunchtheplayerby pressingthePAUSE-buttontwice. ë ♪④SampleFreq Ç YoumaychoosethesamplingfrequencyusedbyPaula.Currently therearethreepossibilities:12.5,25and50KHz.Thehigher thesamplingfrequencythebetterthehighfrequencyresponse. Theoreticallythehighestsoundfrequencyishalfthevalueof thesamplingfrequency(cfShannon'ssamplingtheorem).Onthe Atarihardwareit'sabout40%ofthesamplingfrequency.When using25KHzsamplefreqyougetupto10KHzsoundfrequency. Changesinthesamplingfrequencyareimmediatelyeffective. Duringtheswitchingthesoundismutedforaveryshortmoment toavoidchirpingandclicknoises. ë ♪⑤Player&SoundSetup Ç Inthatareayoufindtwotypesofswitches: *switchestoinfluencethesoundsynthesizer *switchestochangethereplaymodi ♪③êInterpolate:ÇEnablestherealtimeinterpolationofthesamples. Thisgivesamuchbettersoundqualitybutitrequiresalotof CPUpower.OnaTTthisisamustbecausethe68030does multiplicationandshiftopsmuchfasterthanthe68000cpu.By theway,thisalsoappliestothe68020-soifyouhavea020- boardinstalledinyourSTE... ♪④êBooster:ÇIncreasestheoutputsignalby6dBusingalittle trick.Thisimprovesthesignaltonoiseratiobutitalso introducesacertainamountofdistorsions,especiallywhen playinghigh-levelsignals. ♪③êProtracker:ÇEnablestheprotrackercompatibility.Ingeneral, soundmodulesareupwardscompatiblesothatanewplayershould playcorrectlyanoldmodule,butunfortunatelytheprotracker intoducedsomefeatureswhicharemorecritical.Soyouhave thepossibilitytoswitchoffsomeofthenewprotracker commands.However,old15-instrumentmodulesareplayedwith protracker-modedisabled,regardlessoftheswitchposition. ♪²ÇêRepeat:ÇThisswitchhastwomeanings,dependingonhowmany modulesyouhaveselected.Ifyouhaveselectedasinglemodule, thismoduleisrepeated,elsethewholebunchofmodulesis repeated. Bytheway,therearesomemoduleswhichuse'jump'commandsto buildanendlessloop.Paularecognizestheseandinterrupts them. ♪③êRandom:ÇThisistherandomplayfunction.Ifyouhaveselected severalmodules,theywillbeplayedinrandomorder-but everymoduleonlyonetime!Aftereverymodulehasbeenplayed, Paulastopsorrestartsthewholeprocess,dependingonthe 'Repeat'switch. ë ♪④CPU-LoaddisplayÇ ThisbargraphshowstheamountofcputimePaulaneedsforthe soundsynthesis.Itisarelativedisplay,100%arealwaysthe totalcputime,nomatterwhatprocessoryouhave.NoLandmark orNorton-that'ssimplynotinformativeenough. Attherightedgeofthecpuloadbargraphthereisalittlered boxwhichflasheseverytimeyourmachinewasnotfastenough. ♪⑤ëPosition Ç Thisdisplayshowsthecurrentpositioninthemodule.It's usingthehexadecimalformat-youknow,programmersdoitin hex! ♪④ëGeneralinstructions: Ç Themaincommandsaremainlyintuitiveandshouldbeeasyto use.Buttherearealsosomespecialfunctionswhicharenotso evident.Theseare: *leavingthemaindialog *selectingmultiplemodules('multiplaymode') *keycommandlogic *hiddenfeatures ♪③WhenyouclosethemainwindowandPaulaisanaccessory,the playerwillcontinue.Moreoveryoumayclosethiswindowby simplypressingthe<Return>key-analogoustoXCONTROL.ACC. ButifPaularunsasaprogram,closingthemainwindowwill terminatetheprogramandtheplayerwillofcoursebestopped. soinPRGmodeyoucan'tquitbypressing<Return>-youmust clickonthecloser-gadgetofthewindow. ♪²ÇêSelectingmultiplemodules...Ç Thesimplestwaytoselectmorethanonemoduleistouse wildcards.Insteadofselectingafileinthefileselector simplychoosetherightpaththentypethefilespecification, e.g.'A*.MOD'.Thiswouldplayanymodulewhosenamestarts with'A'.Ifyousimplywanttohaveallmodulesplayedwhich arelocatedinonedirectory,simplyselectthatdirectorybut don'tenteraname.Paulawillthenautomaticallyselectany filewhichmatches'*.MOD'. ♪③ê...automatically:Ç Createadirectoryonyourbootdevicewiththename'AUTOMOD' andcopyyourfavoritemodulesintoit.AssoonasPaulais starteditwillplaythesemodules. ♪②Thisfunctionistheonlyonethatdoesn'tworkinunregistered copies. ♪③ê...usingSelectric: ÇIfyouuse'Selectric™'asafileselectoryoumayselect multiplefiles(shift-key+mouseclick),Paulawillloadthem. You'llfinddetailsintheSelectric-manual. Selectric™isasharewareutilitybyStefanRadermacherand OliverScheel. ♪③ê...usingGemini: ÇDragtheiconofPAULA.ACContothedesktopandinstallitas anapplicationfor.MOD-typefiles.NowyoumaycallPaulaby double-clickingit'sicon,playamodulebydouble-clickingit, orevenlistentoseveralmodulesbydraggingthemontothe PAULA-icon. GeminiisasharewareprogrambyGereonSteffensandStefan Eissing. ♪③Somewordsabouttheêkeycommandlogic:ÇPaulaalwaystriesto stayinthecurrentmode.Ifamoduleisrunningandyouload anotherone,thenewlyloadedmoduleisimmediatelyplayed. ♪③IfPaulawasstoppedwhenyouselectmultiplemodules,itwill gointothe'pause'-mode.Thishastobedonethatwaybecause Paulawillforgeteverythingassoonasitentersthe'Stopped'- mode.Isuggestthatyoutrythesecommandstofamiliarize yourselfwithit. ♪⑤ëSetup-Page-dialog Ç Thisdialogboxiscalledwiththe'!'-command.Itofferssome nicefeaturestomanipulatethesoundaswellasthe'save'- function. ♪③êPitchBend(cent):ÇThisisafinetuningfunction.100centis onehalftone,andyoumay(fine-)detunePaulabyonehalftone. Thestandardtuningcorrespondstoa'NTSC'-Amigawith7.15909 MHzclockfrequency.Togetthe'PAL'-Amigatuning,setthe Çpitchbenderto-10..-15cent.Thestepsare5cent,afiner stepisnotneededasthehumanearhasalreadyproblemsto detectadetuningby5cent. ♪③êTranspose:ÇThisisthecoarsetuningfunction.Itchangesthe tuninginhalftonesteps,maximumis12halftoneswhich correspondstooneoctave. ♪③êFrameSpeed:ÇThisisthe'ticker'speedusedasaspeed referenceinthemodule.OntheAmigathisisthe50HzVBlank interrupt,sothestandardsettingis50Hz.Paulaallowsany valuefromhalftodoublespeed(25..100Hz). ♪③êSave:ÇSavesthecurrentsetupintothe'PAULA.INF'fileandthen leavesthedialog.Notethatallsettingsaresaved,themain dialogsettingsaswellasyourregistrationdata. ♪②êExit:ÇLeavesthedialogwithoutchanginganything.Howeverthe changesyouhavemadewillnotbeundone. ♪②êReset:ÇResetsthethreesettings(Pitchfine/coarse,Speed)and leavesthedialog. ♪④ëInfoPagedialog: Ç Theunavoidableinfobox...andalsoanicewaytoremindyou sometimesofthefactthatyouarestillusinganunregistered copy! ♪⑤ëPackedmodules! Ç Paula2.1supportsLZ5orAFXpackedmodules.Tomakesuch packedmodulesyoucanuseLHARC2.01!Supposethatyouhaveall yourmodulesgatheredinthedirectoryC:\AUTOMODandyourhard diskisgettingfull.ThenlaunchLHARC.TTPandenterasa commandline:'ücC:\AUTOMOD\*.MODÇ'.TheLHARCprogramwillthen packallyourmodules,reducingthemtoapproximativlyto75%of theiroriginalsize.Paulawillnotmakeanydifferencebetween packedandunpackedmodules,sothisiscompletelytransparent totheuser. Ifyouareusinganunregisteredcopy,theattempttoloada packedmodulewillonlyissueanerrormessage('Corrupted MODfile'). Ç ♪⑤ëRegistrationprocedure Ç Theinfopagehasabigbuttoninthelowerleftcornerin whichthetext'-unregistered-'iswritten.Ifyouclickonit yougetanotherdialogbox-theregistrationform.That's whereyoumustenteryournameandyouraddressaswellasyour personalkey.IftheseentriesarecorrectPaulaisregistered andtherearenomorerestrictions.Nowifyougetan (unregistered)updateofPaulayouonlyhavetorepeatthis proceduretogetanewregisteredcopy.Thisappliestoall future2.xreleasesofPaula! Togetyourpersonalkey,pleasesendme: ♪④*Yournameandaddress-readable,please! Name:<firstname><lastname> (30charsmaximum) Addr: <street>   (""") City:<zipcode><city>  (""") ♪② *Yoursharewarefee-600FBor30DMorequivalent-withthe remarkthatit'sforPaula.Somepossibilitiesare: ♪②êcashÇ-alwaysOK.Tomakesurethatthemoneyreachesits correctdestinationyoumaysenditasaregisteredletter. payintomyêpostalchequeaccountÇ-agoodway! normalêchequesÇwon'tbeacceptedanylonger,it'stheworst alternativebecausethebankalwaystakesaparttocover miscellaneousfees...(around400FB/20DM).Exception: êEurochequesÇover600FB(FrancBelge)-theseareokay! ♪③AssoonasIgetthemoneyyouwillreceiveyourkeybyletter orE-mail.YoumaythenenteryourdataintoPaula's registrationformandverifyiftheregistrationwassuccesful. Ifsothelargebuttonintheinfodialogentitled'Registered to:'willshowyourname.Inthatcasedon'tforgettosavethe currentsetupsothatPaulawillrememberit'sregisteredstate nexttimeyouboot. Ifitdidn'twork,pleaseverifythespelling-Paulawon't accepterroneousdata. ♪②üImportantnote:ÇNEVERgiveawayyourPAULA.INF-fileasyour registrationdataissavedinthatfile! ♪③Ifyouchangeyouraddressand/ornameyouwillneedanewkey. Inthatcasesendmeyournewdata(apostalcardwilldothe job)andyougetanewkeyassoonaspossible. ♪②IfyouhavemorequestionsorproblemswithPauladon'thesitate towriteme! ë ♪ⁿëErrormessages: Ç Paulanormallyreportserrorsusingstandardalertboxes.To avoidproblemswithunwantedalertboxespoppingupPaulawon't complainaboutit'sproblemsifit'smainwindowisclosed. ♪④Let'sassumeyouselectedthemodules,A.MOD,B.MODandC.MOD; randommodeisoff.PaulastartsplayingA.MOD,theyouclose thewindow.AfterfinishingwithA.MOD,Paulatriestoload B.MOD.IfthisdoesnotsucceedPaulawillstopanyfurther activitiesandwillgointothe'Inactive'state.Ifyouinvoke Paulaandselect'LOAD',youwillseethenameanpathofthe modulewhichcausedtheerror. ♪④Ifyougetthemessage'CorruptedMODfile'thismeansthatthe selectedmodulecannotbeplayed.Inthatcasetrytheutility 'CHECKMOD.TTP'whichanalyzesamoduleandalsorepairsit-if possible. ♪⑥ëMoreinfos... Ç Amodulecontainsupto31differentsampleswhicharealso called'instruments'.Toplayagivensampleatdifferent pitchestheAmigasimplyvariesthereplaysamplingfrequency. Thehigherthesamplingfrequencythehigherthenote.Asthe Amigahasfourindependentsoundchannels,eachonehavingit's ownD/Aconverteritcanplayfourdifferentsamples simultaneouslywithoutthehelpoftheCPU.TheAtarihasonly twochannels(stereoL+R)whicharenotindependentandonly fourfixedsamplingrates.Soanothertrickmustbeusedto simulatetheAmigaChip-the'directdigitalsynthesis',or 'resampling'asthisprocessismorewidelycalled.It'snot difficulttounderstand:thesampledataisnotreplayedata 1:1ratebutwithan1:RratewhereRisafloatingpoint number.IfyouwanttoplayasampleathalfspeedRis2- everybyteofthesampleisoutputtwice.Ifyouwantittobe at75%ofit'soriginalspeed,Ris1.5-thistimeonebyteis outputtwice,thesecondisoutputonceandsoon. Unfortunatelythesamplingdataisoutputirregularly-which givesadistortedsound.Therearetwowaysofeliminating thesedistorsions.Eithermakethestep'R'ratherbig(this wouldrequireverylargesamplesoriginallysampledatavery highrate)orêinterpolateÇtheoutputdata.Thebestthingwould beasplineinterpolationbutunfortunatelythisrequires matrixoperations,soPaulausesasimplelinearinterpolation. Don'tconfuseitwiththe'oversampling'ofsomeothermodule players-theyonlydoubletheoutputdataandsetthesound hardwaretothedoublesamplingfrequency. ♪③Theresultingsoundisofaveryhighquality-at50KHz samplingrateevenbetterthantheAmiga!Thisisduetothe factthattheTT/STEhasno7KHzlowpassfilterwhichcutsoff thehighfrequencies.IftheAmigaswitchesofthisfilterit alsoproducesmoretreblesbutalsomorealiasingcomponents.If ÇyoudoubtaboutthattakeanAmiga,listentoitandreadabout thefactsintheHardwareReferenceManual[2]. ♪③HowevertheAmigahasalargerêdynamicÇrangeduetoit'sfour volumeregisterswhichintroduceanother36dBdynamic-but thatisnotthesamethingasthesignal-to-noiseratiowhichis always48dBfor8bitsystems(theoreticallyofcourse;some systemsaredisturbedbytheRFpresentinthecomputer).The D/AconvertersusedintheAmigaaresometimescalled'floating pointconverters'.InordertocopewiththisPaulahasthe 'Boost'option.Thisoptionsimplysimulatesa9bitD/A converterbyusinganonlinearconversionscheme.Theresultis OKforlowvolumeMODsbutitintroducesadditionaldistorsion athighoutputlevels. ♪④Ifyoudon'tmindabouthowtheinterpolationroutineworks, skipthefollowingparagraph.Ifnot-Ihopeyouknowhowto readaCroutine. ♪⑤/*Fix-Pointnumberrepresentingthestep'R'*/ typedefstructfxp{ intip;/*integerpart(1/1)*/ intfp;/*fractionalpart(1/65536)*/ }fixpoint; ♪⑧ /*Fetchabytefromthesampledataandcalculatethecorrect *'inbetween'value. *Param:spl:Pointertothesample(char*) *index:thearrayindexasFixpoint-number *volume:Amiga-volumeregistervalue,0..64 *Return:theresultingsamplevalueas16bitinteger *range:14bit(8bitsample+6bitvolumeinfo) */ ♪⑨intget_samplevalue(char*spl,fixpointindex,intvolume) { ints1,s2;/*SamplevaluessánÇundsán+1Ç*/ s1=volume*spl[index.ip]; s2=volume*spl[index.ip+1]; return(((s2-s1)*index.fp)/65536+s1); } ♪③Besidesthisroutinetheindexhastobeincremented(addition oftwofixpointnumbers),thereturnvaluemustbescaledand saved,andthesamplemustbecheckedifithasreachedtheend. Astherearefourchannelswhichmustbecalculatedtheabove routineiscalled200,000timespersecond.Tomakethisrunin realtimealotofoptimizationsmustbedone.Eventhe68030 wouldbetotallyoverworkediftheseroutineswerereally writteninC(thatmeans:IambetterthanmyCcompiler...). ëAreallynicechapter:BUGS&LIMITATIONS! Ç ♪③êCollisions: ÇNormallyPaulashouldnotinterferewithanyotherprogram-but problemswithotherutilitiesaccessingthesoundhardwareare unavoidable.Aslongasthe'opponent'iswellprogrammed nothingwillhappen-exceptthatPaulaisstoppedaslongas theotherprogramusesthesoundchip.Asimpletest:runtwo Paulas... ♪③êOverload:Ç Whenyourcomputeristotallyoverloadedtheinternaltimingis somewhatconfused.AsaconsequencethemomentwhenPaulawrites intothesoundregistersisundetermined.Soitmayhappenthat thesoundchipstartsplayingthewrongdata-howeverthe registerscontaintherightvalues!Inthatcase,choosealower samplingfrequencyorswitchoftheinterpolation.Orhaveyou forgottentoturnonthe68030cache??  ♪④êResolutionchange: ÇBeforeyouchangeresolutionsmakesurethatPaulaisinactive. CallPaula,press'STOP'andleavePaulaagain.UnderMultiTOS theproblemmightbesolvediftheOSsendsanAP_TERMmessage toeveryapplication-becausethistellsPaulatostopall activities. ♪④êProtracker'CIA'-replay-speed: ÇFromversion2.2ontheCIAspeedsetupworksexactlyasinthe original.ThedisadvantageisthatsomeNoisetrackermodulesare nowplayedincorrectly;soyouhavetoswitchofftheprotracker modewhenyouplaysuchmodules. ♪④êSystemcrashonSTE's: ÇIknowoftwo1040STEcomputersonwhichPauladoesn'trun.The symptoms:thecomputerfreezes,theonlyescapebeingthereset button.Thisislikelytobeahardwareproblemasthereis absolutelynolinkbetweenthecrashesandthemodulesplayed. Similarsymptomswereexperiencedona1040STEwitha16MHz processorcard-itcrashedduetoacacheproblem.Ifyouhave suchanSTE-sorry,noremedy,it'sahardwarebug! ë ♪④Internals Ç êGEM-UserInterface ÇPaularespondstothe'VA_START'-message(introducedbyGemini). Thismessagecontainsapointer(inmsg[3]andmsg[4])whichis evaluatedbyPaula: ♪②*NULLpointerorpointertoanemptystring:Paulareactsin thesamewayasifitwasanAC_OPENmessage. ♪②*Pointertoastringcontainingonename:Paulatriestoload thismoduleandstartsplayingit. ♪³Ç*Pointertoastringwithseveralspaceseparated modulenames:PaulaenterstheMultiplaymodeandplaysthem all. ♪③ThestringiscopiedinternallybyPaula,soitmaybelocalon thewriter'sside.Howeverthememorymustbereadable-beware oftheMultiTOSmemoryprotection!!! ♪③Thestringalsomustcontaincompletepathandnameindications, NOWILDCARDS.ThesourcecodeofMP(ModPlay)mayserveyouas anexample. ♪③ êMemoryusage ÇPaulaneedssome45KBforit'sprogramcodeanddata.On machineswitha68000processoranother15KBareusedforthe volumetables. ♪③êVectorstealing... ÇPaulausestheIO7interruptofthe68901-MFP.Ofcoursethe 'XBRA'protocolisused,it'smagicis'PAUL'. ♪③êEmergencystop ÇWanttokillPaula?Well,don'tforgettosendanAP_TERM message(GEMmsg#50)toitbeforedoingso. ♪④êSpeeeeed! ÇTosaveCPUtimeonyourTTPaulashouldbeloadedintoFastRAM andtheprocessorcacheshouldbeenabled.WithoutcachePaula willprobablyhaveproblemsdoing50KHzwithinterpolation... Maytheschwartzbewithyou! ♪④ êHardware ÇTimerAandthewonderfulYamahasoundchiparenottouched. Thekeyclickandthewonderful'bell'soundwon'tbeaffected. MoreoveryoumayalsouseSTSPEECHoranyotherutilityto producedigitalsoundeffectsontheYamahachip. ♪③êDevelopment ÇPaula2wasdevelopedusingthePureCcompilerandthePure Assembler.The'realMODplayer',thereplayroutineisbasedon the'Protracker1.1BPlayer'oftheAmigaFreelancers. ♪⑧êThanxforthehelp... ÇIwanttothankthefollowingpeoplefortheirhelp: JoelFrançoisAmigahardwaredocumentation,D.O.C. ReplayRoutine FridolinKochProtrackerreplayroutine,goodMODs Betatesters: GeorgesKesseler Optimizationideas,'Repeat-Finder' ChristianLimpach",STE-DMA-Emulator!!!! Ç ♪⑤ëMP-ModPlayInterface Ç MP.TTPisasimpleutilitywhichgivesyouthepossibilityto launchmodulesfromacommandshell.MPsimplysendsaVA_START messagetoPaula.Mpdoesn'tevaluatewildcardsbutitis awareoftheARGVmethodtodealwithlargecommandlines(link itwith'PCVSTART.O'whencompilingitwithPureC).Thisis idealforusewithMintShelorMupfel. ♪③AlsotrytoinstallMPasaapplicationfor'*.MOD'-filesin thestandardDeskTop-youmaythenlistentomodulesbydouble clickingthem. ♪②MPisnotanexampleforagoodCprogrammingstyle-itisvery simpleandstraightforward.MP.TTPandMP.Carepublicdomain. Ç ♪⑤ëCHECKMOD-themodule-doctor Ç EventuallyPaulawillrefuseamodulewiththecomment 'CorruptedMODfile'.InthatcaseuseCHECKMODtocheckand mayberepairthemoduleinquestion.SimplystartCHECKMODand typeinthenameofthemoduletotest.UnderTOS2.06/3.06drag themodule'siconontotheCHECKMODicon. ♪③Checkmodwillthenreadthemoduleandcontrolit'sinternal structures.Itdisplaysalistwiththeusedintstrumentsand reportstheerror.Thesemaybe: ♪②êCorruptedPatternList:ÇSorry,butthismodulecannotbe repaired. ♪③êShortSample:ÇAsampleistooshort.Ifthisaffectsonlythe lastsampleandifthedifferenceisn'ttoobigCheckmodwill probablybesuccessful.Paulatolerates4lackingbytes. ♪③êSuperfluousDatainMODfile:ÇNoproblem-thismodulssimply hassomegarbageappended.Checkmodcutsitoff,becausePaula toleratesonlyupto256bytesofgarbage. ♪④AfterrunningCheckmodyougetthetext'êSaveModuleas:Ç'.Press <Return>toleave,orenterasingledot'.'tosavethemodule underit'scurrentname.Orenteranewpathandnametosave themoduleusinganothername. Ç ♪⑥ëSupportedmodulecommands Ç $0Arpeggio $1Portamento_up $2Portamento_down $3Noteslide $4Vibrato $5PortamentoDown+Volumeslide $6Vibrato+Volumeslide $7Tremolo $8(PhasorEffect-ignored) $9PlayEndpartofSample $AVolumeslide $BPosition $CSet_volume $DPatternbreak ♪④$EExtendedCommands: E0xFilterOn/Off(ignored) E1xFinePortamentoUp E2xFinePortamentoDown E3xSetGlissandoControl E4xSetVibratoWaveform E5xSetFineTune E6xLoop E7xSetTremoloWaveform E8xStop-ignored!! E9xRetriggerSample EAxFineslideVolumeup EBxFineslideVolumedown ECxNoteCut EDxNoteDelay EExPatternDelay EFxnoop $FSet_speed ëBibliography Ç ü[1]Ç Jankowski/Rabich/Reschke Atari Profibuch ST/STE/TT Sybex Verlag, ISBN 3-88745-888-5 ü[2]Ç Amiga Hardware Reference Manual Addison-Wesley, ISBN 0-201-18157-6 ü[3]Ç Thomsen Digitale Audiotechnik Franzis' Verlag, ISBN 3-7723-7151-5 ü[4]Ç DDS - Direkte Digitale Synthese Elektor Nº257, Mai 1992, s.52ff ü[5]Ç Ulrich Michels dtv Atlas zur Musik, Band 1 (Akustik, Wellenlehre, Tonparameter) Deutscher Taschenbuch Verlag, ISBN 3-423-03022-4 9[....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆....◆.]0010 ëRegistrationform Ç IusePAULA,version2.__andIwanttoregister. Firstandlastname(upto30characters): ______________________________ Youraddress: ______________________________ ______________________________ Someroomforcomments,ideasandbugreports(pleasetellmeabout yourhardwarewhenyouhaveproblemswiththeMODplayer,this helpsalot):