API tools faq
paste
Advertisement
Guest User

Untitled

a guest
Oct 19th, 2015
119
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
text 6.43 KB | None | 0 0
raw download clone embed print report
  1. .enum $0000 ;;start variables at ram location 0
  2.  
  3. currentvirtpos .dsb 1 ; .rs 1 means reserve one byte of space
  4. .ende
  5.  
  6.  
  7. .ORG $7ff0
  8. Header: ; 16 byte .NES header (iNES format)
  9. .DB "NES", $1a
  10. .DB $02 ; size of PRG ROM in 16kb units
  11. .DB $01 ; size of CHR ROM in 8kb units
  12. .DB #%00000000 ; mapper 0
  13. .DB #%00000000 ; mapper 0
  14. .DB $00
  15. .DB $00
  16. .DB $00
  17. .DB $00
  18. .DB $00
  19. .DB $00
  20. .DB $00
  21. .DB $00
  22.  
  23. .ORG $8000
  24.  
  25. sprite_RAM = $0200
  26.  
  27.  
  28. ;;;;;;;;;;;;;;;
  29.  
  30. .org $C000
  31. RESET:
  32. SEI ; disable IRQs
  33. CLD ; disable decimal mode
  34. LDX #$40
  35. STX $4017 ; disable APU frame IRQ
  36. LDX #$FF
  37. TXS ; Set up stack
  38. INX ; now X = 0
  39. STX $2000 ; disable NMI
  40. STX $2001 ; disable rendering
  41. STX $4010 ; disable DMC IRQs
  42.  
  43. vblankwait1: ; First wait for vblank to make sure PPU is ready
  44. BIT $2002
  45. BPL vblankwait1
  46.  
  47. clrmem:
  48. LDA #$00
  49. STA $0000, x
  50. STA $0100, x
  51. STA $0200, x
  52. STA $0400, x
  53. STA $0500, x
  54. STA $0600, x
  55. STA $0700, x
  56. LDA #$FE
  57. STA $0300, x
  58. INX
  59. BNE clrmem
  60.  
  61. LDA #$00
  62. STA currentvirtpos
  63.  
  64. vblankwait2: ; Second wait for vblank, PPU is ready after this
  65. BIT $2002
  66. BPL vblankwait2
  67.  
  68.  
  69. LoadPalettes:
  70. LDA $2002 ; read PPU status to reset the high/low latch
  71. LDA #$3F
  72. STA $2006 ; write the high byte of $3F00 address
  73. LDA #$00
  74. STA $2006 ; write the low byte of $3F00 address
  75. LDX #$00 ; start out at 0
  76. LoadPalettesLoop:
  77. LDA palette, x ; load data from address (palette + the value in x)
  78. ; 1st time through loop it will load palette+0
  79. ; 2nd time through loop it will load palette+1
  80. ; 3rd time through loop it will load palette+2
  81. ; etc
  82. STA $2007 ; write to PPU
  83. INX ; X = X + 1
  84. CPX #$20 ; Compare X to hex $10, decimal 16 - copying 16 bytes = 4 sprites
  85. BNE LoadPalettesLoop ; Branch to LoadPalettesLoop if compare was Not Equal to zero
  86. ; if compare was equal to 32, keep going down
  87.  
  88.  
  89.  
  90. LoadSprites:
  91. LDX #$00 ; start at 0
  92. LoadSpritesLoop:
  93. LDA sprites, x ; load data from address (sprites + x)
  94. STA $0200, x ; store into RAM address ($0200 + x)
  95. INX ; X = X + 1
  96. CPX #$10 ; Compare X to hex $10, decimal 16
  97. BNE LoadSpritesLoop ; Branch to LoadSpritesLoop if compare was Not Equal to zero
  98. ; if compare was equal to 32, keep going down
  99.  
  100.  
  101.  
  102. LDA #%10000000 ; enable NMI, sprites from Pattern Table 1
  103. STA $2000
  104.  
  105. LDA #%00010000 ; enable sprites
  106. STA $2001
  107.  
  108. Forever:
  109. JMP Forever ;jump back to Forever, infinite loop
  110.  
  111.  
  112. ;------------------------------------
  113.  
  114.  
  115.  
  116. NMI:
  117.  
  118.  
  119.  
  120. jsr update_enemy_sprites
  121. jsr movesprites
  122.  
  123.  
  124.  
  125.  
  126. LDA #$00
  127. STA $2003 ; set the low byte (00) of the RAM address
  128. LDA #$02
  129. STA $4014 ; set the high byte (02) of the RAM address, start the transfer
  130.  
  131.  
  132.  
  133.  
  134.  
  135.  
  136.  
  137. RTI ; return from interrupt
  138.  
  139. ;;;;;;;;;;;;;;
  140.  
  141. .org $E000
  142.  
  143. palette:
  144. .db $0f,$03,$13,$23,$0f,$24,$21,$31,$0f,$03,$25,$26,$0f,$09,$19,$29
  145. .db $0f,$03,$13,$23,$0f,$24,$21,$31,$0f,$03,$25,$26,$0f,$09,$19,$29
  146.  
  147. vertpos:
  148. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  149. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  150. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  151. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  152. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  153. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  154. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  155. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  156. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  157. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  158. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  159. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  160. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  161. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  162. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  163. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  164. .db $05,$05,$05,$05,$05,$05,$04,$04,$03,$03,$02,$02,$01,$01,$00,$00
  165. .db $00,$00,$Ff,$Ff,$Fe,$Fe,$Fd,$Fd,$Fc,$Fc,$FB,$FB,$FB,$FB,$FB,$FB
  166.  
  167. sprites:
  168. ;vert tile attr horiz
  169.  
  170.  
  171.  
  172. .db $08, $00, $00, $a4
  173. .db $08, $01, $00, $c9
  174. .db $08, $02, $00, $84
  175. .db $08, $03, $00, $88
  176.  
  177. ;------------------------------------
  178.  
  179. updateconstants: ;constants for the use of the sprite_RAM constant
  180. .db $00 ;4 sprites for each meta sprite, so add $10 for each meta sprite we process
  181.  
  182. ;------------------------------------
  183.  
  184. movesprites:
  185.  
  186. LDA $0203 ; load sprite X position
  187. SEC ; make sure the carry flag is clear
  188. SBC #$01 ; A = A - 1
  189. STA $0203 ; save sprite X position
  190.  
  191. LDA $0200 ; load sprite Y position
  192. CLC ; make sure the carry flag is clear
  193.  
  194. ldx currentvirtpos
  195. ADC vertpos,x ; A = A plus vertposvalue
  196. STA $0200 ; save sprite Y position
  197. inc currentvirtpos
  198.  
  199.  
  200. rts
  201.  
  202. ;------------------------------------
  203.  
  204.  
  205.  
  206. update_enemy_sprites: ;this routine updates the position of the meta sprites relative to each other
  207. LDA sprite_RAM ;vertical updates
  208. STA sprite_RAM+4
  209. CLC
  210. ADC #$8
  211. STA sprite_RAM+8
  212. STA sprite_RAM+12
  213.  
  214. LDA sprite_RAM+3 ;horizontal updates
  215. STA sprite_RAM+11
  216. CLC
  217. ADC #$8
  218. STA sprite_RAM+7
  219. STA sprite_RAM+15
  220.  
  221. RTS
  222.  
  223. ;------------------------------------
  224.  
  225.  
  226.  
  227. .org $FFFA ;first of the three vectors starts here
  228. .dw NMI ;when an NMI happens (once per frame if enabled) the
  229. ;processor will jump to the label NMI:
  230. .dw RESET ;when the processor first turns on or is reset, it will jump
  231. ;to the label RESET:
  232. .dw 0 ;external interrupt IRQ is not used in this tutorial
  233.  
  234.  
  235. ;;;;;;;;;;;;;;
  236.  
  237. .incbin "mario.chr" ;includes 8KB graphics file from SMB1
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement
Public Pastes
Advertisement
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!