6502/n65
1
0
Fork 0
mirror of https://github.com/safiire/n65.git synced 2024-12-12 00:29:03 +00:00
Code Issues Projects Releases Wiki Activity
a5a86d6b60
n65/examples/mario2.asm
Safiire ee643af3ef Binary literals are now working
2015-03-22 15:52:13 -07:00

261 lines
9.7 KiB
NASM
Raw Blame History

;------------------------------------------------------------------------------
; Let's try to recreate a bit of a level from Mario 2
;
;;;;
; Create an iNES header
.ines {"prog": 1, "char": 1, "mapper": 0, "mirror": 0}
;;;;
; Include all the symbols in the nes library
.inc <nes.sym>
;;;;
; Open the prog section bank 0
.segment prog 0
;;;;
; Current horizontal scroll value
.org $0000
.space horizontal_scroll 1
;;;;
; Setup the interrupt vectors
.org $FFFA
.dw vblank
.dw main
.dw irq
;;;;
; Here is our code entry point, which we'll call main.
.org $C000
.scope main
; Disable interrupts and decimal flag
sei
cld
; Wait for 2 vblanks
wait_vb1:
lda nes.ppu.status
bpl wait_vb1
wait_vb2:
lda nes.ppu.status
bpl wait_vb2
; Now we want to initialize the hardware to a known state
lda #$00
ldx #$00
clear_segments:
sta $00, x
sta $0100, x
sta $0200, x
sta $0300, x
sta $0400, x
sta $0500, x
sta $0600, x
sta $0700, x
inx
bne clear_segments
; Reset the stack pointer
ldx #$FF
txs
; Disable all graphics and vblank nmi
lda #$00
sta nes.ppu.control
sta nes.ppu.mask
; Call subroutines to initialize the graphics
jsr load_palette
jsr load_name_tables
jsr init_scrolling
jsr init_ppu
; Resume interrupts and loop here forever
cli
forever:
jmp forever
.
;;;;
; nes.ppu.control: bitpattern is VPHB SINN
; V: NMI enable
; P: PPU master/slave (this does nothing on the NES)
; H: Sprite height 0 = 8x8, 1 = 8x16
; B: Background pattern table address (0: $0000; 1: $1000)
; S: Sprite pattern table address for 8x8 sprites (0: $0000; 1: $1000; ignored in 8x16 mode)
; I: VRAM address increment per CPU read/write of nes.vram.io (0: add 1, going across; 1: add 32, going down)
; NN: Base nametable address (0 = $2000; 1 = $2400; 2 = $2800; 3 = $2C00)
;
; Equivalently, bits 0 and 1 are the most significant bit of the scrolling coordinates
;
; nes.ppu.mask: bitpattern is BGRs bMmG
; BGR: Color emphasis bits
; s: Sprite enable
; b: Background enable
; M: Background left column enable
; m: Sprite left column enable
; G: Greyscale
;
.scope init_ppu
lda #%10001000 ; NMI enable, 8x8 tile, Background: $0000, Sprites: $1000, Address increment: 1, Nametable: $2000
sta nes.ppu.control
lda #%00011110 ; No color emphasis, Enable sprites, Enable Background, Enable sprite and bg left column, no greyscale
sta nes.ppu.mask
rts
.
;;;;
; This initializes the scrolling value in the zero page
; So that we begin offscreen and can scroll down
.scope init_scrolling
lda #$00
sta horizontal_scroll zp
rts
.
;;;;
; Load palette into $3F00
.scope load_palette
lda #$3F
ldx #$00
sta nes.vram.address
stx nes.vram.address
loop:
lda palette, x
sta nes.vram.io
inx
cpx #$20
bne loop
rts
.
;;;;
; Load the background tiles into the name table
.scope load_name_tables
ldy #$00
ldx #$04
lda #<background
sta $10
lda #>background
sta $11
lda #$24
sta nes.vram.address
lda #$00
sta nes.vram.address
loop:
lda ($10), y
sta nes.vram.io
iny
bne loop
inc $11
dex
bne loop
; Now clear the second nametable
ldy #$00
ldx #$04
lda #$00
.scope
loop:
sta nes.vram.io
iny
bne loop
dex
bne loop
.
rts
.
;;;;
; Scroll the screen if we have to
.scope scroll_screen
ldx #$00 ; Reset VRAM Address to $0000
stx nes.vram.address
stx nes.vram.address
ldx horizontal_scroll zp
inx
stx horizontal_scroll zp
lda #$00
stx nes.ppu.scroll ; Write the new horizontal scroll value
sta nes.ppu.scroll ; Write 0 for vertical scroll
rts
.
;;;;
; VBlank routine
.scope vblank
jsr scroll_screen
rti
.
.scope irq
rti
.
;;;;
; Here is a bg palette which I ripped from Mario 2, but, I just put black for sprite palette
palette:
.bytes $21, $30, $12, $0F, $21, $30, $16, $0F, $21, $27, $17, $0F, $21, $29, $1A, $0F
.bytes $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F, $0F
;;;;
; This is the background tile map, or "Name Table" for a bit of a Mario 2 Level.
; Here is how I generated this from a string of hex
; ary.map{|byte| "$%.2X" % byte.to_i(16) }.each_slice(32){|group| puts ".bytes #{group.join(', ')}" }
background:
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BB, $BD, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BB, $BD, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BB, $BD, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BB, $BD, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BB, $BD, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $BA, $BC, $FA, $FA, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $B0, $B1, $B0, $B1, $90, $91, $FA, $FA, $FA, $FA
.bytes $B4, $B6, $B8, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $60, $62, $64, $62, $64, $62, $64, $62, $64, $66, $FA, $FA
.bytes $B5, $B7, $B9, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $46, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $DE, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $FA, $FA, $FA, $FA, $FA, $FA, $B0, $B1, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $FA, $61, $63, $65, $63, $65, $63, $65, $63, $65, $67, $FA, $FA
.bytes $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72, $70, $72
.bytes $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73, $71, $73
.bytes $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF
.bytes $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AE, $AE, $AE, $AE, $AE, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF, $AE, $AF
.bytes $55, $55, $55, $55, $33, $44, $DD, $DD, $57, $55, $55, $55, $33, $44, $DD, $DD, $55, $55, $55, $55, $33, $44, $DD, $DD, $50, $55, $55, $55, $CC, $FF, $FF, $FF
.bytes $55, $55, $55, $54, $FF, $FF, $FF, $FF, $55, $55, $55, $55, $33, $FF, $FF, $FF, $F5, $F5, $F5, $F5, $F3, $FF, $FF, $FF, $5A, $5A, $5A, $5A, $0A, $0A, $0A, $0A
;;;;
; Here we include an entire binary char rom from Mario 2, which contains 4KB of tile data
; No spirte data is included.
.segment char 0
.org $0000
.incbin "mario2.char"
Reference in New Issue View Git Blame Copy Permalink