.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    ;move all sprites off screen
  INX
  BNE clrmem
   
vblankwait2:      ; Second wait for vblank, PPU is ready after this
  BIT $2002
  BPL vblankwait2



; ************** NEW CODE ****************
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
LoadPalettesLoop:
  LDA palette, x        ;load palette byte
  STA $2007             ;write to PPU
  INX                   ;set index to next byte
  CPX #$20            
  BNE LoadPalettesLoop  ;if x = $20, 32 bytes copied, all done




  LDA #$80
  STA $0200        ; put sprite 0 in center ($80) of screen vert
  STA $0203        ; put sprite 0 in center ($80) of screen horiz

  LDA #$00
  STA $0201        ; tile number = 0

;             XX   ;COLOR BITS
  LDA #%00000000
  STA $0202        ; color = 0, no flipping

  LDA #%10000000   ; enable NMI, sprites from Pattern Table 0
  STA $2000

  LDA #%00010000   ; enable sprites
  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
  
  RTI        ; return from interrupt
 
;;;;;;;;;;;;;;  
  
  
  
  .bank 1
  .org $E000
palette:

          ;black             black              black               black
  .db $0F,$0F,$0F,$0F,   $0F,$0F,$0F,$0F,   $0F,$0F,$0F,$0F,   $0F,$0F,$0F,$0F  ;BG PALETTE

          ; reds             greens             blues               grays
  .db $0F,$15,$25,$35,   $0F,$1A,$2A,$3A,   $0F,$12,$22,$32,   $0F,$1D,$2D,$3D  ;SPRITE PALETTE


  .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 "mario.chr"   ;includes 8KB graphics file from SMB1