Subversion Repositories NedoOS

;SMBDIS.ASM - A COMPREHENSIVE SUPER MARIO BROS. DISASSEMBLY (Super Mario Bros (JU))

;by doppelganger (doppelheathen@gmail.com)

;This file is provided for your own use as-is.  It will require the character rom data

;and an iNES file header to get it to work.

;There are so many people I have to thank for this, that taking all the credit for

;myself would be an unforgivable act of arrogance. Without their help this would

;probably not be possible.  So I thank all the peeps in the nesdev scene whose insight into

;the 6502 and the NES helped me learn how it works (you guys know who you are, there's no 

;way I could have done this without your help), as well as the authors of x816 and SMB 

;Utility, and the reverse-engineers who did the original Super Mario Bros. Hacking Project, 

;which I compared notes with but did not copy from.  Last but certainly not least, I thank

;Nintendo for creating this game and the NES, without which this disassembly would

;only be theory.

;Assembles with x816.

;< LOW  low byte

;> HIGH  high byte

;-------------------------------------------------------------------------------------

;DIRECTIVES

        if Z80==0

       .index 8

       .mem 8

       .org $8000

        endif

;-------------------------------------------------------------------------------------

Start:

        if Z80==0

             sei                          ;pretty standard 6502 type init here

             cld

             ldan ++%00010000               ;init PPU control register 1 

             sta PPU_CTRL_REG1

             ldxn ++$ff                     ;reset stack pointer

             txs

VBlank1:     lda PPU_STATUS               ;wait two frames

         checka

             bpl VBlank1

VBlank2:     lda PPU_STATUS

         checka

             bpl VBlank2

        endif

             ldyn16 ++MEMDATA_end-AREADATA;ColdBootOffset          ;load default cold boot pointer

             ldxn ++$05                     ;this is where we check for a warm boot

WBootCheck:  

        if Z80==0

             ldax TopScoreDisplay,x        ;check each score digit in the top score

             cmpn ++10                      ;to see if we have a valid digit

              cmpcy

             bcs ColdBoot                 ;if not, give up and proceed with cold boot

             dex                      

             bpl WBootCheck

             lda WarmBootValidation       ;second checkpoint, check to see if 

             cmpn ++$a5                     ;another location has a specific value

             bne ColdBoot  

             ldyn16 ++WARMMEMDATA_end-AREADATA;WarmBootOffset          ;if passed both, load warm boot pointer

        endif

ColdBoot:    jsr InitializeMemory         ;clear memory using pointer in Y

             sta SND_DELTA_REG+1          ;reset delta counter load register

             sta OperMode                 ;reset primary mode of operation

             ldan ++$a5                     ;set warm boot flag

             sta WarmBootValidation    

             sta PseudoRandomBitReg       ;set seed for pseudorandom register

             ldan ++%00001111

             sta SND_MASTERCTRL_REG       ;enable all sound channels except dmc

        if Z80==0

             ldan ++%00000110

             sta PPU_CTRL_REG2            ;turn off clipping for OAM and background

        endif

             jsr MoveAllSpritesOffscreen

             jsr InitializeNameTables     ;initialize both name tables

             inci DisableScreenFlag        ;set flag to disable screen output

        if Z80==0

             lda Mirror_PPU_CTRL_REG1

             oran ++%10000000               ;enable NMIs

             jsr WritePPUReg1

        endif

             call NonMaskableInterrupt

        call gettimer ;hl=timer

         ld (oldupdtimer),hl

EndlessLoop:

        if Z80

             call EmulatePPU

        call gettimer ;hl=timer

oldupdtimer=$+1

         ld de,oldupdtimer

         ld (oldupdtimer),hl

             or a

             sbc hl,de

        if FASTDEMOBEFOREBREAKPOINT

             ld c,1

             jr z,c_logic0

        else

             jr z,nologic

        endif

             ld c,8

             ld a,l

             cp c

             jr nc,$+3 ;������ ������ ������ � �����������

             ld c,l

c_logic0

            ld hl,logicframe

            ld (hl),c

             ld b,0

             ld d,b

logic0

             call NonMaskableInterrupt

            ld hl,logicframe

            dec (hl)

            jr nz,logic0

                jr logicq

nologic

        ;jr $ ;������� �� �������� ���� ��� ���������� ����

                YIELD;halt

             ld b,0

             ld d,b

logicq

        endif

             jmp EndlessLoop              ;endless loop, need I say more?

        if MUSICONINT

        include "smbsound.asm"

        include "smbmusic.asm"

        ;display $,"<=0x8000"

        endif

;-------------------------------------------------------------------------------------

;$00 - vram buffer address table low, also used for pseudorandom bit

;$01 - vram buffer address table high

VRAM_AddrTable_Low:

      .db LOW VRAM_Buffer1, LOW WaterPaletteData, LOW GroundPaletteData

      .db LOW UndergroundPaletteData, LOW CastlePaletteData, LOW VRAM_Buffer1_Offset

      .db LOW VRAM_Buffer2, LOW VRAM_Buffer2, LOW BowserPaletteData

      .db LOW DaySnowPaletteData, LOW NightSnowPaletteData, LOW MushroomPaletteData

      .db LOW MarioThanksMessage, LOW LuigiThanksMessage, LOW MushroomRetainerSaved

      .db LOW PrincessSaved1, LOW PrincessSaved2, LOW WorldSelectMessage1

      .db LOW WorldSelectMessage2

VRAM_AddrTable_High:

      .db HIGH VRAM_Buffer1, HIGH WaterPaletteData, HIGH GroundPaletteData

      .db HIGH UndergroundPaletteData, HIGH CastlePaletteData, HIGH VRAM_Buffer1_Offset

      .db HIGH VRAM_Buffer2, HIGH VRAM_Buffer2, HIGH BowserPaletteData

      .db HIGH DaySnowPaletteData, HIGH NightSnowPaletteData, HIGH MushroomPaletteData

      .db HIGH MarioThanksMessage, HIGH LuigiThanksMessage, HIGH MushroomRetainerSaved

      .db HIGH PrincessSaved1, HIGH PrincessSaved2, HIGH WorldSelectMessage1

      .db HIGH WorldSelectMessage2

      if Z80

tpalettes

        dw waterpalette

        dw groundpalette

        dw undergroundpalette

        dw castlepalette

      endif

VRAM_Buffer_Offset:

      .db LOW VRAM_Buffer1_Offset, LOW VRAM_Buffer2_Offset

NonMaskableInterrupt:

        if Z80

               ;ldx VRAM_Buffer_AddrCtrl  ;load control for pointer to buffer contents

               ;ldax VRAM_AddrTable_High,x

               ;ld d,a

               ;ldax VRAM_AddrTable_Low,x

               ;ld e,a

               ;ex de,hl

               ;ld de,PPU_SPRLIST

               ;ld bc,0x100

               ;ldir

               ;ex de,hl

               ;ld d,b;0

               lda Mirror_PPU_CTRL_REG1  ;d0 = �������� (��� �������)

               sta PPU_CTRL_REG1

        else

               lda Mirror_PPU_CTRL_REG1  ;disable NMIs in mirror reg

               andn ++%01111111            ;save all other bits

               sta Mirror_PPU_CTRL_REG1

               andn ++%01111110            ;alter name table address to be $2800 ;����� �������� ������ �������� �� ������

               sta PPU_CTRL_REG1         ;(essentially $2000) but save other bits

               lda Mirror_PPU_CTRL_REG2  ;disable OAM and background display by default

               andn ++%11100110

               ldy DisableScreenFlag     ;get screen disable flag

         checky

               bne ScreenOff             ;if set, used bits as-is

               lda Mirror_PPU_CTRL_REG2  ;otherwise reenable bits and save them

               oran ++%00011110

ScreenOff:     sta Mirror_PPU_CTRL_REG2  ;save bits for later but not in register at the moment

               andn ++%11100111            ;disable screen for now

               sta PPU_CTRL_REG2

               ldx PPU_STATUS            ;reset flip-flop and reset scroll registers to zero

               ldan ++$00

               jsr InitScroll ;����� ���� � ������� (����� �� ��������� ����)

               sta PPU_SPR_ADDR          ;reset spr-ram address register

               ldan ++$02                  ;perform spr-ram DMA access on $0200-$02ff

               sta SPR_DMA

        endif

               ldx VRAM_Buffer_AddrCtrl  ;load control for pointer to buffer contents

               ldax VRAM_AddrTable_Low,x  ;set indirect at $00 to pointer

               sta SCRATCHPAD+$00

               ldax VRAM_AddrTable_High,x

               sta SCRATCHPAD+$01

              ;cp 0x03

              ;jr nz,$

               jsr UpdateScreen          ;update screen with buffer contents

               ldyn ++$00

               ldx VRAM_Buffer_AddrCtrl  ;check for usage of $0341 ;VRAM_Buffer2???

               cpxn ++$06

               bne InitBuffer

               iny                       ;get offset based on usage

InitBuffer:    ldxy VRAM_Buffer_Offset,y

               ldan ++$00                  ;clear buffer header at last location

               stax VRAM_Buffer1_Offset,x        

               stax VRAM_Buffer1,x

               sta VRAM_Buffer_AddrCtrl  ;reinit address control to $0301 ;VRAM_Buffer1???

        if Z80==0

               lda Mirror_PPU_CTRL_REG2  ;copy mirror of $2001 to register

               sta PPU_CTRL_REG2

        endif

          if MUSICONINT==0

               jsr SoundEngine           ;play sound

          else

soundenginepatch=$+1

               call SoundEngine_noint           ;play sound logically

          endif

               jsr ReadJoypads           ;read joypads

              if DEMO

              ld a,(readdemo_stopflag)

              or a

              jr nz,randomskip;PauseSkip

              endif

               jsr PauseRoutine          ;handle pause ;������-�� ���� ����, �� ����� ������ �� ���� �������� �����

               jsr UpdateTopScore

               lda GamePauseStatus       ;check for pause status

               lsr

               bcs PauseSkip

              if Z80;OPT

               ld a,(TimerControl)          ;if master timer control not set, decrement

               or a

               jr z,DecTimers             ;all frame and interval timers

               dec a

               ld (TimerControl),a

               jr nz,NoDecTimers

DecTimers:     ;xor a

               ld b,21;ldxn ++$14                  ;load end offset for end of frame timers

               ld hl,IntervalTimerControl

               dec (hl) ;decrement interval timer control,

               ld hl,Timers+20

               jp p,DecTimersLoop         ;if not expired, only frame timers will decrement

               ld a,20

               ld (IntervalTimerControl),a  ;if control for interval timers expired, (21 frame rule???)

               ld b,36;ldxn ++$23                  ;interval timers will decrement along with frame timers

               ld hl,Timers+35

               xor a

DecTimersLoop: cp (hl);ldax Timers,x              ;check current timer

               jr z,SkipExpTimer          ;if current timer expired, branch to skip,

               dec (hl);decx Timers,x              ;otherwise decrement the current timer

SkipExpTimer:  dec hl ;dex                       ;move onto next timer

               djnz DecTimersLoop         ;do this until all timers are dealt with

NoDecTimers:   ld hl,FrameCounter

               inc (hl) ;increment frame counter

              else ;~Z80

               lda TimerControl          ;if master timer control not set, decrement

         checka

               beq DecTimers             ;all frame and interval timers

               deci TimerControl

               bne NoDecTimers

DecTimers:     ldxn ++$14                  ;load end offset for end of frame timers

               deci IntervalTimerControl  ;decrement interval timer control,

               bpl DecTimersLoop         ;if not expired, only frame timers will decrement

               ldan ++$14

               sta IntervalTimerControl  ;if control for interval timers expired, (21 frame rule???)

               ldxn ++$23                  ;interval timers will decrement along with frame timers

DecTimersLoop: ldax Timers,x              ;check current timer

         checka

               beq SkipExpTimer          ;if current timer expired, branch to skip,

               decx Timers,x              ;otherwise decrement the current timer

SkipExpTimer:  dex                       ;move onto next timer

               bpl DecTimersLoop         ;do this until all timers are dealt with

NoDecTimers:   inci FrameCounter          ;increment frame counter

              endif

PauseSkip:     ldxn ++$00

               ldyn ++$07

               lda PseudoRandomBitReg    ;get first memory location of LSFR bytes

               andn ++%00000010            ;mask out all but d1

               sta SCRATCHPAD+$00                   ;save here

               lda PseudoRandomBitReg+1  ;get second memory location

               andn ++%00000010            ;mask out all but d1

               eori SCRATCHPAD+$00                   ;perform exclusive-OR on d1 from first and second bytes

               clc                       ;if neither or both are set, carry will be clear

               beq RotPRandomBit

               sec                       ;if one or the other is set, carry will be set

RotPRandomBit: rorx PseudoRandomBitReg,x  ;rotate carry into d7, and rotate last bit into carry

               inx                       ;increment to next byte

               dey                       ;decrement for loop

               bne RotPRandomBit

randomskip              

               lda Sprite0HitDetectFlag  ;check for flag here

         checka

               beq SkipSprite0

              if Z80==0

Sprite0Clr:    lda PPU_STATUS            ;wait for sprite 0 flag to clear, which will

               andn ++%01000000            ;not happen until vblank has ended

               bne Sprite0Clr

              endif

              if DEMO

              ld a,(readdemo_stopflag)

              or a

              jr nz,Sprite0Hit

              endif

               lda GamePauseStatus       ;if in pause mode, do not bother with sprites at all

               lsr

               bcs Sprite0Hit

               jsr MoveSpritesOffscreen ;3443t (3 Goomba + 2 ���� + �����)

               jsr SpriteShuffler ;545t

Sprite0Hit:

              if Z80==0

               lda PPU_STATUS            ;do sprite ++0 hit detection

               andn ++%01000000

               beq Sprite0Hit ;���, ����� ����� ���� ������� ������� ������ - ��� ����� ��������������� ����

               ldyn ++$14                  ;small delay, to wait until we hit horizontal blank time

HBlankDelay:   dey

               bne HBlankDelay

              endif

SkipSprite0:   lda HorizontalScroll      ;set scroll registers from variables

               sta PPU_SCROLL_REG_H

               lda VerticalScroll

               sta PPU_SCROLL_REG_V

              if Z80==0

               lda Mirror_PPU_CTRL_REG1  ;load saved mirror of $2000

               pha

               sta PPU_CTRL_REG1

              endif

              if DEMO

              ld a,(readdemo_stopflag)

              or a

              jr nz,SkipMainOper

              endif

               lda GamePauseStatus       ;if in pause mode, do not perform operation mode stuff

               lsr ;������ �� � ������ �����??? 1

               bcs SkipMainOper

               jsr OperModeExecutionTree ;otherwise do one of many, many possible subroutines ;49489t (3 Goomba + 2 ���� + �����)

SkipMainOper:

              if Z80==0

               lda PPU_STATUS            ;reset flip-flop

               pla

               oran ++%10000000            ;reactivate NMIs

               sta PPU_CTRL_REG1

              endif

               rti                       ;we are done until the next frame!

;-------------------------------------------------------------------------------------

PauseRoutine:

               lda OperMode           ;are we in victory mode?

               cmpn ++VictoryModeValue  ;if so, go ahead

               beq ChkPauseTimer

               cmpn ++GameModeValue     ;are we in game mode?

               bne ExitPause          ;if not, leave

               lda OperMode_Task      ;if we are in game mode, are we running game engine?

               cmpn ++$03

               bne ExitPause          ;if not, leave

ChkPauseTimer: lda GamePauseTimer     ;check if pause timer is still counting down

         checka

               beq ChkStart

               deci GamePauseTimer     ;if so, decrement and leave

               rts

ChkStart:      lda SavedJoypad1Bits   ;check to see if start is pressed

               andn ++Start_Button      ;on controller 1

               beq ClrPauseTimer

               lda GamePauseStatus    ;check to see if timer flag is set

               andn ++%10000000         ;and if so, do not reset timer (residual,

               bne ExitPause          ;joypad reading routine makes this unnecessary)

               ;jr $

               ldan ++$2b               ;set pause timer

               sta GamePauseTimer

               lda GamePauseStatus

               tay

               iny                    ;set pause sfx queue for next pause mode

               sty PauseSoundQueue

               eorn ++%00000001         ;invert d0 and set d7

               oran ++%10000000

               bne SetPause           ;unconditional branch

ClrPauseTimer: lda GamePauseStatus    ;clear timer flag if timer is at zero and start button

               andn ++%01111111         ;is not pressed

SetPause:      sta GamePauseStatus

ExitPause:     rts

;-------------------------------------------------------------------------------------

;$00 - used for preset value

SpriteShuffler:

        if Z80

        else

               ldy AreaType                ;load level type, likely residual code

               ldan ++$28                    ;load preset value which will put it at

               sta SCRATCHPAD+$00                     ;sprite #10

               ldxn ++$0e                    ;start at the end of OAM data offsets

ShuffleLoop:   ldax SprDataOffset,x         ;check for offset value against

               cmpi SCRATCHPAD+$00                     ;the preset value

              cmpcy

               bcc NextSprOffset           ;if less, skip this part

               ldy SprShuffleAmtOffset     ;get current offset to preset value we want to add

               clc

               adcy SprShuffleAmt,y         ;get shuffle amount, add to current sprite offset

               bcc StrSprOffset            ;if not exceeded $ff, skip second add

               clc

               adci SCRATCHPAD+$00                     ;otherwise add preset value $28 to offset

StrSprOffset:  stax SprDataOffset,x         ;store new offset here or old one if branched to here

NextSprOffset: dex                         ;move backwards to next one

               bpl ShuffleLoop

               ldx SprShuffleAmtOffset     ;load offset

               inx

               cpxn ++$03                    ;check if offset + 1 goes to 3

               bne SetAmtOffset            ;if offset + 1 not 3, store

               ldxn ++$00                    ;otherwise, init to 0

SetAmtOffset:  stx SprShuffleAmtOffset

        endif

               ldxn ++$08                    ;load offsets for values and storage

               ldyn ++$02

SetMiscOffset: lday SprDataOffset+5,y       ;load one of three OAM data offsets

               stax Misc_SprDataOffset-2,x  ;store first one unmodified, but

               clc                         ;add eight to the second and eight

               adcn ++$08                    ;more to the third one

               stax Misc_SprDataOffset-1,x  ;note that due to the way X is set up,

               clc                         ;this code loads into the misc sprite offsets

               adcn ++$08

               stax Misc_SprDataOffset,x        

               dex

               dex

               dex

               dey

               bpl SetMiscOffset           ;do this until all misc spr offsets are loaded (3 �����)

               rts

;-------------------------------------------------------------------------------------

OperModeExecutionTree:

      lda OperMode     ;this is the heart of the entire program,

      jsr JumpEngine   ;most of what goes on starts here

      .dw TitleScreenMode

      .dw GameMode

      .dw VictoryMode

      .dw GameOverMode

;-------------------------------------------------------------------------------------

MoveAllSpritesOffscreen:

              ldyn ++$00                ;this routine moves all sprites off the screen

              jr MoveSpritesOffscreen_go;.db $2c                 ;BIT instruction opcode

MoveSpritesOffscreen:

              ldyn ++$04                ;this routine moves all but sprite 0

MoveSpritesOffscreen_go

              ldan ++$f8                ;off the screen

SprInitLoop:  stay Sprite_Y_Position,y ;write 248 into OAM data's Y coordinate

              iny                     ;which will move it off the screen

              iny

              iny

              iny

              bne SprInitLoop

              rts

;-------------------------------------------------------------------------------------

TitleScreenMode:

      lda OperMode_Task

      jsr JumpEngine

      .dw InitializeGame

      .dw ScreenRoutines

      .dw PrimaryGameSetup

      .dw GameMenuRoutine

;-------------------------------------------------------------------------------------

WSelectBufferTemplate:

      .db $04, $20, $73, $01, $00, $00

GameMenuRoutine:

        ;jr $

              ldyn ++$00

              lda SavedJoypad1Bits        ;check to see if either player pressed

              orai SavedJoypad2Bits        ;only the start button (either joypad)

              cmpn ++Start_Button

              beq StartGame

              cmpn ++A_Button+Start_Button  ;check to see if A + start was pressed

              bne ChkSelect               ;if not, branch to check select button

StartGame:    

        ;jr $

                jmp ChkContinue             ;if either start or A + start, execute here

ChkSelect:    cmpn ++Select_Button          ;check to see if the select button was pressed

              beq SelectBLogic            ;if so, branch reset demo timer

              ldx DemoTimer               ;otherwise check demo timer

         checkx

              bne ChkWorldSel             ;if demo timer not expired, branch to check world selection

              sta SelectTimer             ;set controller bits here if running demo

              jsr DemoEngine              ;run through the demo actions

              bcs ResetTitle              ;if carry flag set, demo over, thus branch

        ;jr $ ;���� ��������

              jmp RunDemo                 ;otherwise, run game engine for demo

ChkWorldSel:  ldx WorldSelectEnableFlag   ;check to see if world selection has been enabled

         checkx

              beq NullJoypad

              cmpn ++B_Button               ;if so, check to see if the B button was pressed

              bne NullJoypad

              iny                         ;if so, increment Y and execute same code as select

SelectBLogic: lda DemoTimer               ;if select or B pressed, check demo timer one last time

        ;jr $ ;���� �������� �� select

         checka

              beq ResetTitle              ;if demo timer expired, branch to reset title screen mode

        ;jr $ ;���� �������� �� select ������ � ����������� ���������

              ldan ++$18                    ;otherwise reset demo timer

              sta DemoTimer

              lda SelectTimer             ;check select/B button timer

         checka

              bne NullJoypad              ;if not expired, branch

              ldan ++$10                    ;otherwise reset select button timer

              sta SelectTimer

              cpyn ++$01                    ;was the B button pressed earlier?  if so, branch

              beq IncWorldSel             ;note this will not be run if world selection is disabled

        ;jr $ ;���� �������� �� select ������ � ����������� ���������

              lda NumberOfPlayers         ;if no, must have been the select button, therefore

              eorn ++%00000001              ;change number of players and draw icon accordingly

              sta NumberOfPlayers

              jsr DrawMushroomIcon

              jmp NullJoypad

IncWorldSel:  ldx WorldSelectNumber       ;increment world select number

              inx

              txa

              andn ++%00000111              ;mask out higher bits

              sta WorldSelectNumber       ;store as current world select number

              jsr GoContinue

UpdateShroom: ldax WSelectBufferTemplate,x ;write template for world select in vram buffer

              stax VRAM_Buffer1-1,x        ;do this until all bytes are written

              inx

              cpxn ++$06

              bmi UpdateShroom

              ldy WorldNumber             ;get world number from variable and increment for

              iny                         ;proper display, and put in blank byte before

              sty VRAM_Buffer1+3          ;null terminator

NullJoypad:   ldan ++$00                    ;clear joypad bits for player 1

              sta SavedJoypad1Bits

RunDemo:      jsr GameCoreRoutine         ;run game engine

              lda GameEngineSubroutine    ;check to see if we're running lose life routine

              cmpn ++$06

              bne ExitMenu                ;if not, do not do all the resetting below

ResetTitle:   ldan ++$00                    ;reset game modes, disable

              sta OperMode                ;sprite 0 check and disable

              sta OperMode_Task           ;screen output

              sta Sprite0HitDetectFlag

              inci DisableScreenFlag

              rts

ChkContinue:  ldy DemoTimer               ;if timer for demo has expired, reset modes

         checky

                ;jr $

              beq ResetTitle ;������ ������ �����??? ���� ����������������, �� �� ���� �� Start �������� �� � ����, � � ����, � ������� �����, ���� �� ��� �������

              asl                         ;check to see if A button was also pushed

              bcc StartWorld1             ;if not, don't load continue function's world number

              lda ContinueWorld           ;load previously saved world number for secret

              jsr GoContinue              ;continue function when pressing A + start

StartWorld1:  jsr LoadAreaPointer

        ;jr $ ;���� �������� �� start

              inci Hidden1UpFlag           ;set 1-up box flag for both players

              inci OffScr_Hidden1UpFlag

              inci FetchNewGameTimerFlag   ;set fetch new game timer flag

              inci OperMode                ;set next game mode

              lda WorldSelectEnableFlag   ;if world select flag is on, then primary

              sta PrimaryHardMode         ;hard mode must be on as well

              ldan ++$00

              sta OperMode_Task           ;set game mode here, and clear demo timer

              sta DemoTimer

              ldxn ++$17

              ldan ++$00

InitScores:   stax ScoreAndCoinDisplay,x   ;clear player scores and coin displays

              dex

              bpl InitScores

ExitMenu:     rts

GoContinue:   sta WorldNumber             ;start both players at the first area

              sta OffScr_WorldNumber      ;of the previously saved world number

              ldxn ++$00                    ;note that on power-up using this function

              stx AreaNumber              ;will make no difference

              stx OffScr_AreaNumber  

              rts

;-------------------------------------------------------------------------------------

MushroomIconData:

      .db $07, $22, $49, $83, $ce, $24, $24, $00

DrawMushroomIcon:

              ldyn ++$07                ;read eight bytes to be read by transfer routine

IconDataRead: lday MushroomIconData,y  ;note that the default position is set for a

              stay VRAM_Buffer1-1,y    ;1-player game

              dey

              bpl IconDataRead

              lda NumberOfPlayers     ;check number of players

         checka

              beq ExitIcon            ;if set to 1-player game, we're done

              ldan ++$24                ;otherwise, load blank tile in 1-player position

              sta VRAM_Buffer1+3

              ldan ++$ce                ;then load shroom icon tile in 2-player position

              sta VRAM_Buffer1+5

ExitIcon:     rts

;-------------------------------------------------------------------------------------

DemoActionData:

      .db $01, $80, $02, $81, $41, $80, $01

      .db $42, $c2, $02, $80, $41, $c1, $41, $c1

      .db $01, $c1, $01, $02, $80, $00

DemoTimingData:

      .db $9b, $10, $18, $05, $2c, $20, $24

      .db $15, $5a, $10, $20, $28, $30, $20, $10

      .db $80, $20, $30, $30, $01, $ff, $00

DemoEngine:

          ldx DemoAction         ;load current demo action

          lda DemoActionTimer    ;load current action timer

         checka

          bne DoAction           ;if timer still counting down, skip

          inx

          inci DemoAction         ;if expired, increment action, X, and

          sec                    ;set carry by default for demo over

          ldax DemoTimingData-1,x ;get next timer

        if Z80

        sec

        endif

          sta DemoActionTimer    ;store as current timer

         checka

          beq DemoOver           ;if timer already at zero, skip

DoAction: ldax DemoActionData-1,x ;get and perform action (current or next)

          sta SavedJoypad1Bits

          deci DemoActionTimer    ;decrement action timer

          clc                    ;clear carry if demo still going

DemoOver: rts

;-------------------------------------------------------------------------------------

VictoryMode:

            jsr VictoryModeSubroutines  ;run victory mode subroutines

            lda OperMode_Task           ;get current task of victory mode

         checka

            beq AutoPlayer              ;if on bridge collapse, skip enemy processing

            ldxn ++$00

            stx ObjectOffset            ;otherwise reset enemy object offset 

            jsr EnemiesAndLoopsCore     ;and run enemy code

AutoPlayer: jsr RelativePlayerPosition  ;get player's relative coordinates

            jmp PlayerGfxHandler        ;draw the player, then leave

VictoryModeSubroutines:

      lda OperMode_Task

      jsr JumpEngine

      .dw BridgeCollapse

      .dw SetupVictoryMode

      .dw PlayerVictoryWalk

      .dw PrintVictoryMessages

      .dw PlayerEndWorld

;-------------------------------------------------------------------------------------

SetupVictoryMode:

      ldx ScreenRight_PageLoc  ;get page location of right side of screen

      inx                      ;increment to next page

      stx DestinationPageLoc   ;store here

      ldan ++EndOfCastleMusic

      sta EventMusicQueue      ;play win castle music

      jmp IncModeTask_B        ;jump to set next major task in victory mode

;-------------------------------------------------------------------------------------

PlayerVictoryWalk:

             ldyn ++$00                ;set value here to not walk player by default

             sty VictoryWalkControl

             lda Player_PageLoc      ;get player's page location

             cmpi DestinationPageLoc  ;compare with destination page location

             bne PerformWalk         ;if page locations don't match, branch

             lda Player_X_Position   ;otherwise get player's horizontal position

             cmpn ++$60                ;compare with preset horizontal position

              cmpcy

             bcs DontWalk            ;if still on other page, branch ahead

PerformWalk: inci VictoryWalkControl  ;otherwise increment value and Y

             iny                     ;note Y will be used to walk the player

DontWalk:    tya                     ;put contents of Y in A and

             jsr AutoControlPlayer   ;use A to move player to the right or not

             lda ScreenLeft_PageLoc  ;check page location of left side of screen

             cmpi DestinationPageLoc  ;against set value here

             beq ExitVWalk           ;branch if equal to change modes if necessary

             lda ScrollFractional

             clc                     ;do fixed point math on fractional part of scroll

             adcn ++$80        

             sta ScrollFractional    ;save fractional movement amount

             ldan ++$01                ;set 1 pixel per frame

             adcn ++$00                ;add carry from previous addition

             tay                     ;use as scroll amount

             jsr ScrollScreen        ;do sub to scroll the screen

             jsr UpdScrollVar        ;do another sub to update screen and scroll variables

             inci VictoryWalkControl  ;increment value to stay in this routine

ExitVWalk:   lda VictoryWalkControl  ;load value set here

         checka

             beq IncModeTask_A       ;if zero, branch to change modes

             rts                     ;otherwise leave

;-------------------------------------------------------------------------------------

PrintVictoryMessages:

               lda SecondaryMsgCounter   ;load secondary message counter

         checka

               bne IncMsgCounter         ;if set, branch to increment message counters

               lda PrimaryMsgCounter     ;otherwise load primary message counter

         checka

               beq ThankPlayer           ;if set to zero, branch to print first message

               cmpn ++$09                  ;if at 9 or above, branch elsewhere (this comparison

              cmpcy

               bcs IncMsgCounter         ;is residual code, counter never reaches 9)

               ldy WorldNumber           ;check world number

               cpyn ++World8

               bne MRetainerMsg          ;if not at world 8, skip to next part

               cmpn ++$03                  ;check primary message counter again

              cmpcy

               bcc IncMsgCounter         ;if not at 3 yet (world 8 only), branch to increment

              cmpcy

               sbcn ++$01                  ;otherwise subtract one

               jmp ThankPlayer           ;and skip to next part

MRetainerMsg:  cmpn ++$02                  ;check primary message counter

              cmpcy

               bcc IncMsgCounter         ;if not at 2 yet (world 1-7 only), branch

ThankPlayer:   tay                       ;put primary message counter into Y

         checka

               bne SecondPartMsg         ;if counter nonzero, skip this part, do not print first message

               lda CurrentPlayer         ;otherwise get player currently on the screen

         checka

               beq EvalForMusic          ;if mario, branch

               iny                       ;otherwise increment Y once for luigi and

               bne EvalForMusic          ;do an unconditional branch to the same place

SecondPartMsg: iny                       ;increment Y to do world 8's message

               lda WorldNumber

               cmpn ++World8               ;check world number

               beq EvalForMusic          ;if at world 8, branch to next part

               dey                       ;otherwise decrement Y for world 1-7's message

               cpyn ++$04                  ;if counter at 4 (world 1-7 only)

              cmpcy

               bcs SetEndTimer           ;branch to set victory end timer

               cpyn ++$03                  ;if counter at 3 (world 1-7 only)

              cmpcy

               bcs IncMsgCounter         ;branch to keep counting

EvalForMusic:  cpyn ++$03                  ;if counter not yet at 3 (world 8 only), branch

               bne PrintMsg              ;to print message only (note world 1-7 will only

               ldan ++VictoryMusic         ;reach this code if counter = 0, and will always branch)

               sta EventMusicQueue       ;otherwise load victory music first (world 8 only)

PrintMsg:      tya                       ;put primary message counter in A

               clc                       ;add $0c or 12 to counter thus giving an appropriate value,

               adcn ++$0c                  ;($0c-$0d = first), ($0e = world 1-7's), ($0f-$12 = world 8's)

               sta VRAM_Buffer_AddrCtrl  ;write message counter to vram address controller

IncMsgCounter: lda SecondaryMsgCounter

               clc

               adcn ++$04                      ;add four to secondary message counter

               sta SecondaryMsgCounter

               lda PrimaryMsgCounter

               adcn ++$00                      ;add carry to primary message counter

               sta PrimaryMsgCounter

               cmpn ++$07                      ;check primary counter one more time

              cmpcy

SetEndTimer:

               bcc ExitMsgs                  ;if not reached value yet, branch to leave

               ldan ++$06

               sta WorldEndTimer             ;otherwise set world end timer

IncModeTask_A: inci OperMode_Task             ;move onto next task in mode

ExitMsgs:      rts                           ;leave

;-------------------------------------------------------------------------------------

PlayerEndWorld:

               lda WorldEndTimer          ;check to see if world end timer expired

         checka

               bne EndExitOne             ;branch to leave if not

               ldy WorldNumber            ;check world number

               cpyn ++World8                ;if on world 8, player is done with game, 

              cmpcy

               bcs EndChkBButton          ;thus branch to read controller

               ldan ++$00

               sta AreaNumber             ;otherwise initialize area number used as offset

               sta LevelNumber            ;and level number control to start at area 1

               sta OperMode_Task          ;initialize secondary mode of operation

               inci WorldNumber            ;increment world number to move onto the next world

               jsr LoadAreaPointer        ;get area address offset for the next area

               inci FetchNewGameTimerFlag  ;set flag to load game timer from header

               ldan ++GameModeValue

               sta OperMode               ;set mode of operation to game mode

EndExitOne:    rts                        ;and leave

EndChkBButton: lda SavedJoypad1Bits

               orai SavedJoypad2Bits       ;check to see if B button was pressed on

               andn ++B_Button              ;either controller

               beq EndExitTwo             ;branch to leave if not

               ldan ++$01                   ;otherwise set world selection flag

               sta WorldSelectEnableFlag

               ldan ++$ff                   ;remove onscreen player's lives

               sta NumberofLives

               jsr TerminateGame          ;do sub to continue other player or end game

EndExitTwo:    rts                        ;leave

;-------------------------------------------------------------------------------------

;data is used as tiles for numbers

;that appear when you defeat enemies

FloateyNumTileData:

      .db $ff, $ff ;dummy

      .db $f6, $fb ; "100"

      .db $f7, $fb ; "200"

      .db $f8, $fb ; "400"

      .db $f9, $fb ; "500"

      .db $fa, $fb ; "800"

      .db $f6, $50 ; "1000"

      .db $f7, $50 ; "2000"

      .db $f8, $50 ; "4000"

      .db $f9, $50 ; "5000"

      .db $fa, $50 ; "8000"

      .db $fd, $fe ; "1-UP"

;high nybble is digit number, low nybble is number to

;add to the digit of the player's score

ScoreUpdateData:

      .db $ff ;dummy

      .db $41, $42, $44, $45, $48

      .db $31, $32, $34, $35, $38, $00

FloateyNumbersRoutine:

              ldax FloateyNum_Control,x     ;load control for floatey number

         checka

              beq EndExitOne               ;if zero, branch to leave

              cmpn ++$0b                     ;if less than $0b, branch

              cmpcy

              bcc ChkNumTimer

              ldan ++$0b                     ;otherwise set to $0b, thus keeping

              stax FloateyNum_Control,x     ;it in range

ChkNumTimer:  tay                          ;use as Y

              ldax FloateyNum_Timer,x       ;check value here

         checka

              bne DecNumTimer              ;if nonzero, branch ahead

              stax FloateyNum_Control,x     ;initialize floatey number control and leave

              rts

DecNumTimer:  decx FloateyNum_Timer,x       ;decrement value here

              cmpn ++$2b                     ;if not reached a certain point, branch  

              bne ChkTallEnemy

              cpyn ++$0b                     ;check offset for $0b

              bne LoadNumTiles             ;branch ahead if not found

              inci NumberofLives            ;give player one extra life (1-up)

              ldan ++Sfx_ExtraLife

              sta Square2SoundQueue        ;and play the 1-up sound

LoadNumTiles: lday ScoreUpdateData,y        ;load point value here

              lsr                          ;move high nybble to low

              lsr

              lsr

              lsr

              tax                          ;use as X offset, essentially the digit

              lday ScoreUpdateData,y        ;load again and this time

              andn ++%00001111               ;mask out the high nybble

              stax DigitModifier,x          ;store as amount to add to the digit

              jsr AddToScore               ;update the score accordingly

ChkTallEnemy: ldyx Enemy_SprDataOffset,x    ;get OAM data offset for enemy object

              ldax Enemy_ID,x               ;get enemy object identifier

              cmpn ++Spiny

              beq FloateyPart              ;branch if spiny

              cmpn ++PiranhaPlant

              beq FloateyPart              ;branch if piranha plant

              cmpn ++HammerBro

              beq GetAltOffset             ;branch elsewhere if hammer bro

              cmpn ++GreyCheepCheep

              beq FloateyPart              ;branch if cheep-cheep of either color

              cmpn ++RedCheepCheep

              beq FloateyPart

              cmpn ++TallEnemy

              cmpcy

              bcs GetAltOffset             ;branch elsewhere if enemy object =HIGH  $09

              ldax Enemy_State,x

              cmpn ++$02                     ;if enemy state defeated or otherwise

              cmpcy

              bcs FloateyPart              ;$02 or greater, branch beyond this part

GetAltOffset: ldx SprDataOffset_Ctrl       ;load some kind of control bit

              ldyx Alt_SprDataOffset,x      ;get alternate OAM data offset

              ldx ObjectOffset             ;get enemy object offset again

FloateyPart:  ldax FloateyNum_Y_Pos,x       ;get vertical coordinate for

              cmpn ++$18                     ;floatey number, if coordinate in the

              cmpcy

              bcc SetupNumSpr              ;status bar, branch

              cmpcy

              sbcn ++$01

              stax FloateyNum_Y_Pos,x       ;otherwise subtract one and store as new

SetupNumSpr:  ldax FloateyNum_Y_Pos,x       ;get vertical coordinate

             or a

              sbcn ++$08                     ;subtract eight and dump into the

              jsr DumpTwoSpr               ;left and right sprite's Y coordinates

              ldax FloateyNum_X_Pos,x       ;get horizontal coordinate

              stay Sprite_X_Position,y      ;store into X coordinate of left sprite

              clc

              adcn ++$08                     ;add eight pixels and store into X

              stay Sprite_X_Position+4,y    ;coordinate of right sprite

              ldan ++$02

              stay Sprite_Attributes,y      ;set palette control in attribute bytes

              stay Sprite_Attributes+4,y    ;of left and right sprites

              ldax FloateyNum_Control,x

              asl                          ;multiply our floatey number control by 2

              tax                          ;and use as offset for look-up table

              ldax FloateyNumTileData,x

              stay Sprite_Tilenumber,y      ;display first half of number of points

              ldax FloateyNumTileData+1,x

              stay Sprite_Tilenumber+4,y    ;display the second half

              ldx ObjectOffset             ;get enemy object offset and leave

              rts

;-------------------------------------------------------------------------------------

ScreenRoutines:

      lda ScreenRoutineTask        ;run one of the following subroutines

      jsr JumpEngine

      .dw InitScreen ;0

      .dw SetupIntermediate ;1

      .dw WriteTopStatusLine ;2

      .dw WriteBottomStatusLine ;3

      .dw DisplayTimeUp ;4

      .dw ResetSpritesAndScreenTimer ;5

      .dw DisplayIntermediate ;6

      .dw ResetSpritesAndScreenTimer ;7

      .dw AreaParserTaskControl ;8