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07200000208800 1 2page # F0000000 9[...................................................]011 ü ëPALETTEMASTER Ç ByKevinCowtan êCONTENTS Ç ü 1.Ç Introduction. ü 2.Ç GettingStarted. 2.1 DrawingFacilities. 2.2 ColourSelection. 2.3 OtherFacilitiesü 3.Ç AdvancedGraphics. ü 4.Ç Programmers'Guide. Ç ü1.ÇêINTRODUCTION Ç ArtprogramsarenowfairlycommonontheAtariST,and thereisacompetitionbetweenvariouscompaniestowritetheart programwiththegreatestrangeoffacilities.However,in general,apicturewhichcanbedrawnononeartprogramcanalso bedrawnonalltheothers,althoughitmaybeeasierormore difficultdependingonthefacilitiesprovided.PaletteMasteris different.WithPaletteMasteryoucandrawpicturesthatare beyondthescopeofotherprograms,orevenloadexisting picturesandimprovethem. PaletteMasterisuniqueinthatitallowsyoutodraw picturesusingmorethantheST'susuallimitof16colourson thescreenatonetime.Thismeansthatartistscannowproduce picturesontheSTfarsuperiortothosepreviouslyavailable. Thesepicturescanthenbeusedinotherprograms,orjustshown asworksofcomputerart.Inadditiontomakingpicturesmore colourful,specialgraphicstechniquesallowpicturestobe improvedinotherways. Howmanycolourscanyouuseonthescreen?Theoretically, PaletteMasterallowstheuseofalloftheST's512colourson thescreenatonce,howevertheprogramisnotwithout limitations.Theactualnumberofcolourswhichcanbeusefully usedinapicturegenerallyvariesbetweenabout20and50.The limitationisthatonly16colourscanbedisplayedonanyscreen line(ormoreaccurately,anypairofscreenlines). Whataretheeffectsofthislimitation?Consideraland⑨ scapepicture.Atthetopofthescreentheskyisblue,fading towardswhiteatthehorizon.Inthebackgroundtherearehills, andintheforegroundaretreeswiththeirtopssilhouetted againstthesky.Nowsupposeweuse5shadesofblue/whitefor thesky.Tofadetowhitewecolourhorizontalbandsofskyin progressivelylightercolours,andshadetheedgesofthebands together.Thiswillonlyusetwocoloursatmostonanyscreen line,astheworstpossiblesituationisalinewheretheedges oftwobandsareshadedtogether.Thisleavesuswiththeborder colour,and13shadesofgreenandbrownforthetreetops.Ifwe wantedcloudsinthesky,4orsoofthesecolourscouldbe allocatedforthatpurpose. Furtherdownthescreen,thehillsappearbetweenthetrees. Wecanusecolourfortheborder,1colourfortheskybetween thehills,6coloursforthehillsthemselves,and8coloursfor thetreesintheforeground.Belowthisthebackgroundcomes towardstheobserver,andthiscanberepresentedbyprogressi⑨ velylightercoloursfortheground.Atthebottomofthescreen, 15colourscanbeallocatedfortheground,theplants,andthe treetrunks. Asdescribedabovethispicturewillprobablyuseatleast 30colours.Withsometouchingup,itcouldeasilyuse40or50, agreatimprovementonthenormal16. Ç Iftheartisthadtoconsidereverypicturelikethis,then drawingusingPaletteMasterwouldbecomeverylaborious.However nosuchconsiderationisrequired.PaletteMasterhasbeen writtenspecificallytodoallthesetasksautomatically,sothat alltheartistneeddoispickoneofthe512coloursanddraw withit.Theallocationandarrangementofcoloursinthepicture isalldonebyaroutinecalledthe'AutomaticPaletteManager' (APM).Asaresultthepackageisextraordinarilysimpletouse, moresoperhapsthaneventhemoreconventionalartprograms availablefortheST. Thebestwaytolearntousethepackageistouseit,so loaduptheprogramandgothroughthe'GettingStarted'section ofthismanualtryingoutalltheoptions. 9[...................................................]011 Çü2.ÇêGETTINGSTARTED Ç TousePaletteMaster,youwillneedanAtari520ST/STM/STFM a1040STF,oraMegaST.YouwillalsoneedaTVorcolour monitor. PutthePaletteMasterdiskinthediskdrive,andturnon yourmachine.TheGemdesktopshouldappear,withawindow showingthefilesonthedisk.Doubleclicktheprogramicon labelled'_PALART.PRG'.Theartprogramwillnowloadfromdisk. Thescreenwillnowturnblack,andamenuoficonswillbe drawnatthebottomofthescreen.Thisisthemenubar,andthis particularsetoficonsiscalledtheMainMenu.Theicons,from lefttoright,represent: 1. Apaintbrush. 2. Aspraycan. 3. Alinebeingdrawnbyacrosshaircursor. 4. Anellipse. 5. Acanofpaint,forfillinginadrawing. 6. Alettert,fortext. 7. Ablockofpicturebeingmoved. 8. Amagnifyingglass,fordetailedwork. 9. Adisk,forsavingorloadingpictures. Thelastboxshowsyouwhichcolourisselectedatthe moment,calledtheworkcolour.Anydrawingyoudoonthescreen willappearinthiscolour. Youwillnoticethattheboxcontainingthepaintbrushis litupatthemoment.Thepaintbrushisthereforetheselected option.Ifyouclickoneoftheothericons(i.e.pointthemouse atitandpresstheleftbutton),thatwillbecometheselected option.Tryselectingsomeoftheothericons.Thenselectthe brushagain. Tousethecurrentoption,allyouhavetodoisclickthe mouseattheareaabovethemenubar.Ifyouhadthebrush selected,youwillhavearoundmousecursoronthescreen.Press theleftmousebutton.Ifyounowmovethemouseyouwillsee thatithasleftaroundblobonthescreenintheworkcolour. Ifyouholddowntheleftmousebuttonandmovethemouse,it willleaveatrailofcolourbehindit.Thisishowyoudrawwith thebrush. Nowpresstherightmousebutton.Themainmenuwill reappearatthebottomofthescreen.Thebrushshouldstillbe selected,butthistimeclickitagain.Themainmenuwillbe replacedbytheBrushMenu.Ontheleftisthebrushicon,to showyouwhichmenuyouarein.Ontherightistheworkcolour. Inthemiddleare16brushes,ofdifferentshapesandsizes.The largeroundbrushontheleftisselected.Clickanotherbrushto selectit,andthenclickthescreentodrawwithit. Ifyoupresstherightbuttonfromamenu,thecolour selectorscreenwillappear.Thiswillbeexplainedlater,so presstherightbuttonagaintogettothedrawingscreen,and oncemoretogetbacktothemainmenu. Youcanclickanyicontoselectit,butifyouclickthe currentlyselectediconaspecialmenuforthaticonwillappear, (ifoneexists).Clickthemainscreentodraw,andtheright buttontomovetothemenu,thecolourselector,andbacktothe drawingscreeninturn.Alltheoptionscanbeusedinthisway, andinthenextsectiontheyarelistedwiththeirpurposeand theirsub-menus. Ç ü2.1ÇêDRAWINGFACILITIES Ç êBrushÇ: Whentheleftbuttonispressedthebrushdrawsonthe screen.Thebrushsub-menuallowsyoutoselecttheshape andsizeofthebrush. êSprayÇ: Whentheleftbuttonishelddownthisoptionwill paintonthescreenlikeanairbrush.Thespraysub-menu allowsyoutoselecttheradiusinpixelsofthespray,and howfastthesprayfillsanarea.1isslowand3isfast. êLineDrawÇ: Thelinedrawingoptionwilldrawastraightline betweentwopointsonthescreen.Pointthecrosshairatthe startpositionandclicktheleftbutton.Nowmovethemouse towhereyouwantittoend.Alinewillbedraggedout joiningthepoints.Clicktheleftbuttontodrawtheline, ortherightbuttontocancelit.Thereisnosubmenufor linedrawing. êEllipseÇ: Thisoptionwilldrawacircleorellipseonthe screen.Clickwhereyouwantthecentretobe,andthenmove themouseawayfromthispointtodrawanellipse.Click whenitistherightshape,orpresstherightbuttonto cancelit. êPaint(Fill)Ç: Thisoptionisusedforfillinginanenclosed areawiththeworkcolour,orwithamixtureofthework colourandtheshadecolour,whichwewillcometolater.To usethefillcan,justclicktheinteriorofanenclosed shape,anditwillbefilledwithcolour.Thefillsub-menu showstwocoloursontheright,theworkcolourandthe shade colour.Inthemiddleisaselectionof8shading patterns.Clickanyoneofthesetoselectit. üNote:ÇThefilloptionwillnotfillinanyshapewithshade ifitisalreadyfilledwitheithertheworkcolourorthe shadecolour.Youwillhavetofillitwithanothercolour first. êTextÇ: Thisoptionallowsyoutoputtextonyourpicture.To useitpointthecrosshairatwhereyouwantthebottom left-handedgeofthefirstcharactertobegin.Aline cursortheheightofthelettersyouareusingwillappear. Typeyoutextonthekeyboardnormally.Backspacewilllet youstartagain,undowilltakeyoubacktothecrosshair mode,andreturnwillputthetextpermanentlyonthe screen.Thetextsub-menuwillallowyoutoselectoneof sixtextheights,giveninpixels.Theä'iÇ'andü'bÇ'icons willselectäitalicÇandüboldÇmodesrespectively. êBlockMoveÇ: Thisoptionallowsyoutocutarectangularblock outofthepictureandtopasteitsomewhereelseonthe screen.Touseitpositionthecrosshairatonecornerof theblockyouwishtocut,thenpressandholddowntheleft button.Movethemousetotheoppositecorneroftheblock youwanttomove,andthenreleasethebutton.Anoutlined rectanglewillthenallowyoutopositiontheblockonthe screen.Presstheleftbuttontopastetheblockorthe rightbuttontoreturntoblockcutmode.Notethatifyou returntothemenuwithoutcuttinganewblock,theoldone willbepreserved,andnexttimeyouusetheblockmove facilityyouwillautomaticallygointoblockpastemode. Thisallowsanotherpicturetobeloaded,andablockfrom onepicturetobepastedontoanother.  Therearetwomodesforblockmove:normalandtranspa⑨ rent.Transparentmodeisselectedonloadingtheprogram, butyoucanswitchtonormalmodebyclickingtheblockicon whenitisselected.Theiconwillreflectthisselection.  Innormalmode,ablockispastedintoplaceis identicaltotheoriginalblock.Intransparentmode however,anypartofablockthatisdrawnintheborder colourwillbetransparentinthepasteoperation.Whatwas onthescreenfirstwillshowthroughtheseareasofthe block.Thisisusefulformovingnon-rectangularpictures aboutthescreen. êMagnifyÇ: Thisoptionwillenlargeasmallareaofscreenfor detailedwork.Touseitpositiontherectangleoverthe areaonwhichyouwanttoworkandpresstheleftbutton. Theareaintherectanglewillbeenlargedfourtimes.You candrawonthescreeninthecurrentworkcolourusingthe leftbutton,orreturntothenormalscreenwiththeright button.Thereisalsoashortcuttothecolourselector screenbyclickingthemenubar.Thereisnomagnifysub- menu. êDiskAccessÇ: Thisoptionhasnoeffectonthescreen,however youcanselectthesub-menu.Thefirstoptiononthedisk menu,thepartiallyshaderectangle,isaclearscreen facility.Itwillerasethedrawingscreenandsetthe bordertoblack.  Thenextthreeoptionsareforloadingpicturesfrom disk.Theywillload.NEO,.PI1,and.ARTfilesrespecti⑨ vely.The.NEOand.PI1formatsareforloadingpictures generatedbyothergraphicsprograms,and.ARTisaspecial formatusedforPaletteMasterpictures.  Ifyouclickoneoftheseoptionsyouwillbepresented withtheItemSelectorwindow.Youcanpickafiletoload eitherbytypingitsname,orbyclickingonitsnameinthe diskcatalogue.Pressreturnorclickon'OK'toloadthe file.Thenclickonthescreenandthepicturewillappear.  Thelasttwooptionsonthismenuareusedtosave picturesin.ARTand.PRGformatsrespectively.The.ART formatismostusefulasyoucanreloadandmodifypictures storedinthisformat.The.PRGformatisanextraoption whichallowsfinishedpicturestobesavedasprogramfiles whichcanthenberundirectlyfromtheGEMdesktop,orfrom otherprograms.  Selectthefilenametosaveusingthefileselectoras before.Youwillusuallywanttotypeinanewfilenamewhen savingpictures,otherwiseyouwilleraseanexisting picture. 9[...................................................]011 Ç ü2.2ÇêTheColourSelectionScreenÇ Thisscreencanbereachedeitherbypressingtheright buttonfromamenuscreen,orbyclickingtheenlargescreenmenu bar. OntheleftofthescreenyouwillseetheST'spaletteof 512colours.Youcanmakeanyoneoftheseintotheworkcolour simplybypointingthemouseatthecolourandpressingtheleft button. Ontherighthandsideofthisscreenthereareother facilitiesavailable.Atthetopisaboxcontainingthecurrent workcolour,whichcanbechangedasdescribedabove.Belowthis isaboxwhichtellsyoutheRGBvaluesoftheworkcolour.These describeonascaleof0-7howmuchred,greenandblue respectivelythereisintheworkcolour. Belowthisare4iconswhichaffectcolourchoice.Theyare: SetScreenBorder PickColourfromScreen Optimisepalettes PickcolourfromAPMpalettes The'Setscreenborder'iconwillsetthescreenborder colourtothecurrentworkcolour.Thiswillnotshowuponthe palettescreen,butchangestheborderaroundtheedgeofthe pictureonthemaindrawingscreen. The'Pickcolourfromscreen'iconallowsyoutopicka colourfromthosealreadyusedonthescreen.Youwillbeshown themaindrawingscreen.Clickonthecolouryouwanttoselect, orpresstherightbuttontoreturntothecolourselection withoutchoosingacolour. The'Optimise'iconwilltelltheAutomaticPaletteManager tooptimisethesetofcoloursusedonthescreen.Itexamines thescreenpictureandworksoutwhichcoloursareusedoneach line.Anyunusedcoloursareflaggedasunallocatedcolours.In generalyouneedonlyclickitafterloading.NEOor.PI1files. The'Pickfrompalettes'iconallowsyoutopickacolour fromthescreenjustliketheoptionaboveit,howeveritalso displaystheAPMpalettesdowntherighthandsideofthescreen. Eachverticalbandrepresentsoneofthe16coloursavailableon anyscreenline.Lookatthisoptionafterdrawingonthescreen, andyouwillseethattheAPMbuildsupcoloursfromrightto left(colour16tocolour1).Thewhitebands(orblackbands againstalightborder)representunallocatedcolours.The programwillnotallowyoutoselectoneofthese. Atthebottomofthiswindowisaboxcontainingthefill shadingcolour,whichismixedwiththeworkcolourwhenusing theshadedfillfacility.Ifyouclickthisbox,thenthecurrent workcolourbecomesthefillshadingcolour. êRUNNINGOUTOFCOLOURS Ç Ifatanytimeyoutrytousemorethan16coloursona screenline(orpairoflines),thenthecomputerwillringa belltowarnyou.Itwilldrawasmuchitcan,butwillnot modifythoselinesonwhichnocoloursareavailable.Sometimes themousecursorchangescolour,andthismaybeawarningthat youarerunningoutofcolours. Toavoidthissituation,trytore-usecoloursasoftenas possiblebyusingthe'pickfromscreen'optiondescribedabove. ü 2.3ÇêOTHERFACILITIES Ç Therearetwoadditionalfacilitiesavailabletomakethe programeasiertouse.Theseare: êUndoÇ: IfyoupresstheUndokey(abovethecursorkeys) whilstinanydrawingmode,theneverythingyouhavedonetothe screensinceyoulastusedamenuwillbeerased.Thiscanbe usedforerasingmistakes.Thisfunctionisnotavailablewhilst thescreenisenlargedandbehavesslightlydifferentlyintext mode.Howeveritcanbeusedwhilstpositioningtheenlargebox. êHelpÇ: IfyoupresstheHelpkeywhilstinanydrawingmode exceptblockmoveorenlarge,thentheareaofscreenaboutthe cursorwillbemagnified.Pressingtheleftbuttonwillthen executetheselecteddrawingfacilityatthepixelpointedtoby themouse.Therightbuttonwillreturntothenormaldrawing screen.Inthismanneritispossibletopositionthemouse accuratelyfordrawing.Thisfacilityisusefulforfilling smallshapes,oraccuratelycenteringellipses,orjustfor checkingyourwork. Ç ü3.ÇêADVANCEDGRAPHICS Ç Thissectionwilltrytomakesomesuggestionsabouthowto getthebestfromPaletteMaster. Thefirstthingyoucandotoproducebetterpicturesisto lookforpictureswithhorizontaldivisions,likethesimple landscapedescribedintheintroduction.Theprogramonly allows16coloursonanyoneline,howeverifthepictureis dividedintohorizontalregionsthendifferentsetsofcolours canbeusedforeachregion.ThisiswhatPaletteMasterdoes best,althoughitcaninvariablyimproveotherpicturesaswell. Secondly,don'tjustaddcolourstoexistingpictures becausetheyareavailable.Usetheextracoloursfor'touching up'smallareasofthepicture.Inthiswayitiseasytouse morethan50coloursinapictureandobtainamuchmorerefined result.Aparticularapplicationofthisisatechniquecalled 'edgesoftening',amethodbywhichextracolourscanbeusedto makeapictureappeartobedrawninamuchhigherresolution. Whenadiagonallineisdrawonthescreenitappears jagged,owingtothelimitsoftheST'sresolution.However,we canfooloureyesintoseeingasmoothedgebyfillinginthe stepsinadiagonallinewithanintermediatecolour,i.e.one withRGBvalueshalfwaybetweentheRGBvaluesofthecolours eithersideoftheedge.Formoreeffectiveresultsseveral colourscanbeused.Thistechniquehasbeenusedonthedemo picture'DISCS.ART'.Thediscsintherighthalfofthepicture havebeen'edgesoftened'.Examinethemwithenlargemodeandyou willsoongettheidea. ThistechniquehaslittleapplicationoutsidePaletteMaster becausetherearenotenoughcoloursavailable.However,with PaletteMasteritcanbeusedtogreateffect. 9[...................................................]011 Ç ü4.ÇêPROGRAMMERS'GUIDE Ç Thefollowingfacilitiesareprovidedfortheuseof PaletteMasterpicturesinyourownprograms: 1. Picturesmaybesavedas.PRGfiles,whichyoucanthenuse frommachinecodewiththeGEMDOSfunctionEXEC.Someversionsof Chaveafunction'loadex'whichwillloadandexecutea.PRG filewithouterasingtheexistingprogram.Eitherofthesewill loadanddisplayapictureuntilakeyispressed,whencontrol shouldbereturnedtotheoriginalprogram. 2. Thefile'_PALHBL.USE'canbeusedbyassemblycode programmerstodisplaypictures.Itcontainstheinterrupt routinesusedbyPaletteMastertochangethescreenpalette. ThisshouldallowyoutousePaletteMasterpicturesas backgroundsforanimation,oryoucanusetheroutinesfor completelydifferentpurposes. Tousethisfile,loaditwiththeGEMDOSfunctionsOPEN, READ,andCLOSE.TheninassemblycodeexecuteaJSRinstruction tothefirstaddressinthefile.Thiswillsetupthe68000 traps3-10tocontroltheroutine.UnliketheGEMtraps, parametersarepassedinregisters.Thetrapsbehaveasfollows: êTRAP #3Ç: Enabletheinterruptroutines.TheGEMverticalblank, keyboard,andtimerCinterruptsaredisabled.ThePaletteMaster VBL,paletteswitching,andkeyboardinterruptsareenabled. Whilepaletteswitchingisenabledyoushouldavoidall supervisorcallsexceptthosetotheseroutines.Inparticular thosecallsdependingontheaboveinterruptswillcrashthe computer,andmostGEMcallswillbeunusable. êTRAP #4Ç:Disabletheinterruptroutines.ThisrestorestheGEM interruptstothestatetheywereinbeforetheTRAP#3. êTRAP #5Ç: Changethecurrentscreenandmulti-paletteaddresses. Thisallowsapictureanywhereinmemorytobeviewed,aslongas itstartsona256-bytepageboundary.Thenewscreenbase addressispassedinA1,andthemulti-paletteaddressinA2.The constructionofmulti-palettesisexplainedlater.Ifyouloadan .ARTfile,A1shouldbesettothebaseaddressofthefile,and A2tothisaddress+32768. êTRAP #6Ç: Turnonthemousecursor.Themousecursorwillappear onthescreenandcanbemovedbymovingthemouse.Themouse cursorwillinitiallybeoff. êTRAP #7Ç: Turnoffthemousecursor.Themousecursorwill disappear.Notethattomakethemousere-appearitmustbe turnedononceforeachtimeitwasturnedoff. êTRAP #8Ç: Changethemousecursor.Theaddressofthenewmouse cursorispassedtotheroutineinA1.Thisregistershouldpoint toastandardGEMspritedefinitionblock,asusedbythe$A00C and$A00Dopcodes. Ç êTRAP #9Ç: Returnthekeyboardpointers.Callingthisroutinewill returntwoparametersintheaddressregisters: A0: Thisisthepointertoakeyboardtable.Thebytesof thistablecontainthescancodes(nottheasciicodes)ofkeys currentlypressedintheorderthatthewerepressed.Thetable isterminatedby$ff.Ifthisvalueisthefirstbyteinthe tablethennokeysarecurrentlypressed.Youcanacknowledgea keybyreplacingitwith$ffifyoudon'twantittobedetected again. A1: Thisisapointertothemousetable,whichcontains threewords.Thefirsttwocontainthemousexandycoordinates respectively.Bit0ofthethirdwordcontainstherightbutton status,andbit1theleft. A2isalsochanged. êTRAP #10Ç: Playalistofsounds.Apointertoasoundstringis passedinA1.Thissoundstringshouldhavethesameconstruction astheXBIOSsoundprimitive,exceptthatcodes128and129are notimplemented. êTRAP#11Ç: Restorethestatusregister.Ifyoumustmakeacallto asupervisorroutinethatdoesnotdependontheGEMinterrupts, thenfollowingitwiththiscallêmayÇpreventproblems. Notethatapartfromtraps3and4,thesecallsonlycorruptA0. êMULTI-PALETTESÇ Amulti-palettehasthefollowingconstruction: Thefirst32bytesshouldcontainthe16colourstobeused atthetopofthescreen. Subsequentblocksof32bytescontainawordwiththeline onwhichthenextpalettechangeshouldoccur(from1-199), followedbythenewcolourvaluesforcolours1to15. Aterminationvalueof$ffffshouldfollowthefinalblock. Youshouldnotattempttochangethepaletteontwoadjacent screenlines,astherewillnotenoughtimeforkeyboard interruptstooccur,possiblycausingacrash. Ifonlytheinitialpaletteandterminationvalueare includedintheblock,thenthepaletteswitchinginterruptwill notbeenabled,sotheroutinegivenbelowwillnotwork.Sucha multi-paletteisdefineduntilyouenableanewonewithTRAP#5. PaletteMaster.ARTfilesusethefollowingmulti-palette format.Thetop-of-screenpaletteisfollowedbyanewpalette foreachevennumberedscreenline,i.e.therenewpalettesfor lines2,4,6,8....198.Thereforean.ARTfilemulti-palettetakes up322bytes,includingterminationvalue.PaletteMaster picturesusethecoloursindescendingorderstartingwithcolour 15,soifyouwanttousecoloursforspritessetcolours1,2,3 etcfromassemblycodeineachlineonwhichthespriteistobe used. êWAIT-FOR-VERTICAL-BLANKÇ Theroutinegivenbelowwillwaitforaverticalblank interrupt.Itcanbecalledfromusermode,aslongasamulti- palettewithatleastonepalettechange(inadditiontothe initialpalette)isinuse. waitvbl move.w sr,d7 btst #9,d7 beq.s waitvbl waitvbl2move.w sr,d7 btst #9,d7 bne.s waitvbl2 rts êEXAMPLEPROGRAM Ç Toclarifythissectionanexampleprogramisprovided; '_EXAMPLE.PRG'whichloadsthepicture'_DISCS.ART'anddisplays itonthescreenwiththemousecursoruntilakeyispressed. Theassemblycodeforthissimpleprogramisincludedbelow: section example * * * * * * * * * * start move.w #2,-(sp) ; find current base of screen trap #14 addq.l #2,sp lea gemscrn,a0 ; and store it move.l d0,(a0) lea filenm1,a4 ; load _PALHBL.USE move.l #$60000,a5 move.l #$800,a6 bsr.s open jsr $60000 ; set up traps lea filenm2,a4 ; load DISCS.ART move.l #$68000,a5 ; address move.l #$9000,a6 ; length bsr.s open trap #3 ; enable routines move.l #$68000,a1 ; base of picture move.l #$70000,a2 ; base of multi-palette trap #5 ; show picture trap #6 ; turn on mouse trap #9 ; get keyboard pointers waitkey tst.b (a0) ; wait for a key bmi.s waitkey done move.l gemscrn,a1 ; restore gem screen and lea default,a2 ; a one line palette trap #5 moveq #-1,d0 ; wait for a while until waitpal dbra d0,waitpal ; for new palette to appear trap #4 ; disable routines clr.w -(sp) ; end program trap #1 Ç* * * * * * * * * * open clr.w -(sp) ; open picture file move.l a4,-(sp) ; a4 -> filename move.w #$3d,-(sp) trap #1 addq.l #8,sp tst.w d0 bmi.s diskerr move.w d0,-(sp) ; store file handle read move.l a5,-(sp) ; read pic to data area move.l a6,-(sp) move.w d0,-(sp) move.w #$3f,-(sp) trap #1 add.w #12,sp close move.w #$3e,-(sp) ; close pic file trap #1 ; handle already on stack addq.l #4,sp diskerr rts * * * * * * * * * * picbase dc.l 0 gemscrn dc.l 0 filenm1 dc.b 'A:_PALHBL.USE',0 filenm2 dc.b 'A:DISCS.ART',0 default dc.w $777,$700,$070,$770,$007,$707,$077,$555 dc.w $333,$733,$373,$773,$337,$737,$377,$000 dc.w -1 * * * * * * * * * * end