diff options
Diffstat (limited to 'src/example/snes.asm')
| -rw-r--r-- | src/example/snes.asm | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/example/snes.asm b/src/example/snes.asm new file mode 100644 index 0000000..bea3235 --- /dev/null +++ b/src/example/snes.asm @@ -0,0 +1,127 @@ + processor 65c816 + + option output-file,snes.sfc + option output-format,snes + + option snes-irq,vbl,handler + option snes-irq,irq,handler + + ; Initialise SNES + ; + org $8000 + + sei + clc + xce + ldx #$1fff + txs + + sep #$30 ; X,Y,A are 8 bit numbers + lda #$8F ; screen off, full brightness + sta $2100 ; brightness + screen enable register + stz $2101 ; Sprite register (size + address in VRAM) + stz $2102 ; Sprite registers (address of sprite memory [OAM]) + stz $2103 ; "" "" + stz $2105 ; Mode 0, = Graphic mode register + stz $2106 ; noplanes, no mosaic, = Mosaic register + stz $2107 ; Plane 0 map VRAM location + stz $2108 ; Plane 1 map VRAM location + stz $2109 ; Plane 2 map VRAM location + stz $210A ; Plane 3 map VRAM location + stz $210B ; Plane 0+1 Tile data location + stz $210C ; Plane 2+3 Tile data location + stz $210D ; Plane 0 scroll x (first 8 bits) + stz $210D ; Plane 0 scroll x (last 3 bits) #$0 - #$07ff + lda #$FF ; The top pixel drawn on the screen isn't the top one in the tilemap, it's the one above that. + sta $210E ; Plane 0 scroll y (first 8 bits) + sta $2110 ; Plane 1 scroll y (first 8 bits) + sta $2112 ; Plane 2 scroll y (first 8 bits) + sta $2114 ; Plane 3 scroll y (first 8 bits) + lda #$07 ; Since this could get quite annoying, it's better to edit the scrolling registers to fix this. + sta $210E ; Plane 0 scroll y (last 3 bits) #$0 - #$07ff + sta $2110 ; Plane 1 scroll y (last 3 bits) #$0 - #$07ff + sta $2112 ; Plane 2 scroll y (last 3 bits) #$0 - #$07ff + sta $2114 ; Plane 3 scroll y (last 3 bits) #$0 - #$07ff + stz $210F ; Plane 1 scroll x (first 8 bits) + stz $210F ; Plane 1 scroll x (last 3 bits) #$0 - #$07ff + stz $2111 ; Plane 2 scroll x (first 8 bits) + stz $2111 ; Plane 2 scroll x (last 3 bits) #$0 - #$07ff + stz $2113 ; Plane 3 scroll x (first 8 bits) + stz $2113 ; Plane 3 scroll x (last 3 bits) #$0 - #$07ff + lda #$80 ; increase VRAM address after writing to $2119 + sta $2115 ; VRAM address increment register + stz $2116 ; VRAM address low + stz $2117 ; VRAM address high + stz $211A ; Initial Mode 7 setting register + stz $211B ; Mode 7 matrix parameter A register (low) + lda #$01 + sta $211B ; Mode 7 matrix parameter A register (high) + stz $211C ; Mode 7 matrix parameter B register (low) + stz $211C ; Mode 7 matrix parameter B register (high) + stz $211D ; Mode 7 matrix parameter C register (low) + stz $211D ; Mode 7 matrix parameter C register (high) + stz $211E ; Mode 7 matrix parameter D register (low) + sta $211E ; Mode 7 matrix parameter D register (high) + stz $211F ; Mode 7 center position X register (low) + stz $211F ; Mode 7 center position X register (high) + stz $2120 ; Mode 7 center position Y register (low) + stz $2120 ; Mode 7 center position Y register (high) + stz $2121 ; Color number register ($0-ff) + stz $2123 ; BG1 & BG2 Window mask setting register + stz $2124 ; BG3 & BG4 Window mask setting register + stz $2125 ; OBJ & Color Window mask setting register + stz $2126 ; Window 1 left position register + stz $2127 ; Window 2 left position register + stz $2128 ; Window 3 left position register + stz $2129 ; Window 4 left position register + stz $212A ; BG1, BG2, BG3, BG4 Window Logic register + stz $212B ; OBJ, Color Window Logic Register (or,and,xor,xnor) + sta $212C ; Main Screen designation (planes, sprites enable) + stz $212D ; Sub Screen designation + stz $212E ; Window mask for Main Screen + stz $212F ; Window mask for Sub Screen + lda #$30 + sta $2130 ; Color addition & screen addition init setting + stz $2131 ; Add/Sub sub designation for screen, sprite, color + lda #$E0 + sta $2132 ; color data for addition/subtraction + stz $2133 ; Screen setting (interlace x,y/enable SFX data) + stz $4200 ; Enable V-blank, interrupt, Joypad register + lda #$FF + sta $4201 ; Programmable I/O port + stz $4202 ; Multiplicand A + stz $4203 ; Multiplier B + stz $4204 ; Multiplier C + stz $4205 ; Multiplicand C + stz $4206 ; Divisor B + stz $4207 ; Horizontal Count Timer + stz $4208 ; Horizontal Count Timer MSB (most significant bit) + stz $4209 ; Vertical Count Timer + stz $420A ; Vertical Count Timer MSB + stz $420B ; General DMA enable (bits 0-7) + stz $420C ; Horizontal DMA (HDMA) enable (bits 0-7) + stz $420D ; Access cycle designation (slow/fast rom) + + cli ; Enable interrupts + + ; Set the background color to green. + sep #$20 ; Set the A register to 8-bit. + lda #%10000000 ; Force VBlank by turning off the screen. + sta $2100 + lda #%11100000 ; Load the low byte of the green color. + sta $2122 + lda #%00000000 ; Load the high byte of the green color. + sta $2122 + lda #%00001111 ; End VBlank, setting brightness to 15 (100%). + sta $2100 + + ; Loop forever. +Forever: + jmp Forever + + +; IRQ vectors +; + +handler: + rti |