.inesprg 1 ; 1x 16KB PRG code .ineschr 1 ; 1x 8KB CHR data .inesmap 0 ; mapper 0 = NROM, no bank swapping .inesmir 1 ; background mirroring ;;;;;;;;;;;;;;; .bank 0 .org $C000 RESET: SEI ; disable IRQs CLD ; disable decimal mode LDX #$40 STX $4017 ; disable APU frame IRQ LDX #$FF TXS ; Set up stack INX ; now X = 0 STX $2000 ; disable NMI STX $2001 ; disable rendering STX $4010 ; disable DMC IRQs vblankwait1: ; First wait for vblank to make sure PPU is ready BIT $2002 BPL vblankwait1 clrmem: LDA #$00 STA $0000, x STA $0100, x STA $0300, x STA $0400, x STA $0500, x STA $0600, x STA $0700, x LDA #$FE STA $0200, x INX BNE clrmem vblankwait2: ; Second wait for vblank, PPU is ready after this BIT $2002 BPL vblankwait2 LoadPalettes: LDA $2002 ; read PPU status to reset the high/low latch LDA #$3F STA $2006 ; write the high byte of $3F00 address LDA #$00 STA $2006 ; write the low byte of $3F00 address LDX #$00 ; start out at 0 LoadPalettesLoop: LDA palette, x ; load data from address (palette + the value in x) ; 1st time through loop it will load palette+0 ; 2nd time through loop it will load palette+1 ; 3rd time through loop it will load palette+2 ; etc STA $2007 ; write to PPU INX ; X = X + 1 CPX #$20 ; Compare X to hex $10, decimal 16 - copying 16 bytes = 4 sprites BNE LoadPalettesLoop ; Branch to LoadPalettesLoop if compare was Not Equal to zero ; if compare was equal to 32, keep going down LoadSprites: LDX #$00 ; start at 0 LoadSpritesLoop: LDA sprites, x ; load data from address (sprites + x) STA $0200, x ; store into RAM address ($0200 + x) INX ; X = X + 1 CPX #$20 ; Compare X to hex $10, decimal 16 BNE LoadSpritesLoop ; Branch to LoadSpritesLoop if compare was Not Equal to zero ; if compare was equal to 16, keep going down LoadBackground: LDA $2002 ; read PPU status to reset the high/low latch LDA #$20 STA $2006 ; write the high byte of $2000 address LDA #$00 STA $2006 ; write the low byte of $2000 address LDX #$00 ; start out at 0 LoadBackgroundLoop: LDA background, x ; load data from address (background + the value in x) STA $2007 ; write to PPU INX ; X = X + 1 CPX #$FF ; Compare X to hex $80, decimal 128 - copying 128 bytes BNE LoadBackgroundLoop ; Branch to LoadBackgroundLoop if compare was Not Equal to zero ; if compare was equal to 128, keep going down LoadAttribute: LDA $2002 ; read PPU status to reset the high/low latch LDA #$23 STA $2006 ; write the high byte of $23C0 address LDA #$C0 STA $2006 ; write the low byte of $23C0 address LDX #$00 ; start out at 0 LoadAttributeLoop: LDA attribute, x ; load data from address (attribute + the value in x) STA $2007 ; write to PPU INX ; X = X + 1 CPX #$08 ; Compare X to hex $08, decimal 8 - copying 8 bytes BNE LoadAttributeLoop ; Branch to LoadAttributeLoop if compare was Not Equal to zero ; if compare was equal to 128, keep going down LDA #%10010000 ; enable NMI, sprites from Pattern Table 0, background from Pattern Table 1 STA $2000 LDA #%00011110 ; enable sprites, enable background, no clipping on left side STA $2001 Forever: JMP Forever ;jump back to Forever, infinite loop NMI: LDA #$00 STA $2003 ; set the low byte (00) of the RAM address LDA #$02 STA $4014 ; set the high byte (02) of the RAM address, start the transfer LatchController: LDA #$01 STA $4016 LDA #$00 STA $4016 ; tell both the controllers to latch buttons ButtonA: LDA $4016 ; player 1 - A AND #%00000001 ; look only at bit 0 BNE ButtonB ; Button stuff here ButtonB: LDA $4016 ; player 1 - B AND #%00000001 ; look only at bit 0 BNE SelectButton ; Button stuff here SelectButton: LDA $4016 ; player 1 - Select AND #%00000001 ; look only at bit 0 BNE StartButton ; Button stuff here StartButton: LDA $4016 ; player 1 - Start AND #%00000001 ; look only at bit 0 BNE UpButton ; Button stuff here UpButton: LDA $4016 ; player 1 - Up AND #%00000001 ; look only at bit 0 BNE DownButton ; Button stuff here DownButton: LDA $4016 ; player 1 - Down AND #%00000001 ; look only at bit 0 BNE LeftButton ; Button stuff here LeftButton: LDA $4016 ; player 1 - Left AND #%00000001 ; look only at bit 0 BNE RightButton LDA $0203 ; load sprite X position CLC ; make sure the carry flag is clear ADC #$01 ; A = A + 1 STA $0203 ; save sprite X position LDA $0207 ; load sprite X position CLC ; make sure the carry flag is clear ADC #$01 ; A = A + 1 STA $0207 ; save sprite X position LDA $020B ; load sprite X position CLC ; make sure the carry flag is clear ADC #$01 ; A = A + 1 STA $020B ; save sprite X position LDA $020F ; load sprite X position CLC ; make sure the carry flag is clear ADC #$01 ; A = A + 1 STA $020F ; save sprite X position LDA $0213 CLC ADC #$01 STA $0213 LDA $0217 CLC ADC #$01 STA $0217 LDA $021B CLC ADC #$01 STA $021B LDA $021F CLC ADC #$01 STA $021F RightButton: LDA $4016 ; player 1 - Right AND #%00000001 ; look only at bit 0 BNE NotRightButton LDA $0203 ; load sprite X position SEC ; make sure carry flag is set SBC #$01 ; A = A - 1 STA $0203 ; save sprite X position LDA $0207 ; load sprite X position SEC ; make sure carry flag is set SBC #$01 ; A = A - 1 STA $0207 ; save sprite X position LDA $020B ; load sprite X position SEC ; make sure carry flag is set SBC #$01 ; A = A - 1 STA $020B ; save sprite X position LDA $020F ; load sprite X position SEC ; make sure carry flag is set SBC #$01 ; A = A - 1 STA $020F ; save sprite X position LDA $0213 CLC ADC #$01 STA $0213 LDA $0217 CLC ADC #$01 STA $0217 LDA $021B CLC ADC #$01 STA $021B LDA $021F CLC ADC #$01 STA $021F NotRightButton: JMP ButtonA RTI ; return from interrupt ;;;;;;;;;;;;;; ;;;;;;;;;;;;;; .bank 1 .org $E000 palette: .db $22,$0F,$27,$26, $22,$0F,$16,$26, $22,$30,$21,$0F, $22,$27,$17,$0F ;;background palette .db $22,$0F,$27,$1A, $22,$0F,$27,$26, $22,$1C,$15,$14, $22,$02,$38,$3C ;;sprite palette sprites: ;vert tile attr horiz .db $80, $00, $00, $80 ;sprite 0 .db $80, $01, $00, $88 ;sprite 1 .db $88, $10, $00, $80 ;sprite 2 .db $88, $11, $00, $88 ;sprite 3 .db $90, $20, $00, $80 ;sprite 4 .db $90, $21, $00, $88 ;sprite 5 .db $98, $30, $00, $80 ;sprite 6 .db $98, $31, $00, $88 ;sprite 7 background: .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 1 .db $24,$24,$24,$24,$24,$24,$24,$24,$08,$09,$0A,$0B,$24,$24,$24,$24 ;;first tile of sun .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 2 .db $24,$24,$24,$24,$24,$24,$24,$24,$18,$19,$1A,$1B,$24,$24,$24,$24 ;;second tile of sun .db $24,$24,$24,$24,$24,$24,$01,$02,$01,$02,$24,$24,$01,$02,$01,$02 ;;row 3 .db $24,$24,$01,$02,$01,$02,$24,$24,$28,$29,$2A,$2B,$24,$24,$24,$24 ;;third tile of sun with first tile of block .db $24,$24,$24,$24,$24,$24,$11,$12,$11,$12,$24,$24,$11,$12,$11,$12 ;;row 4 .db $24,$24,$11,$12,$11,$12,$24,$24,$38,$39,$3A,$3B,$24,$24,$24,$24 ;;forth and last tile of sun with the second and last tile of block .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 5 .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;all sky .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 6 .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;all sky .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 7 .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;all sky .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;row 8 .db $24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24,$24 ;;all sky attribute: .db %00000000, %00010000, %01010000, %00010000, %00000000, %00000000, %00000000, %00110000 .db $24,$24,$24,$24, $47,$47,$24,$24 ,$47,$47,$47,$47, $47,$47,$24,$24 ,$24,$24,$24,$24 ,$24,$24,$24,$24, $24,$24,$24,$24, $55,$56,$24,$24 ;;brick bottoms .org $FFFA ;first of the three vectors starts here .dw NMI ;when an NMI happens (once per frame if enabled) the ;processor will jump to the label NMI: .dw RESET ;when the processor first turns on or is reset, it will jump ;to the label RESET: .dw 0 ;external interrupt IRQ is not used in this tutorial ;;;;;;;;;;;;;; .bank 2 .org $0000 .incbin "eddinlevel.chr" ;includes 8KB graphics file from SMB1