; SNES ROM startup code ;****************************************************************************** ;*** Define a special section in case most of the code is not in bank 0. *** ;****************************************************************************** ;STACK EQU $01ff ;CHANGE THIS FOR YOUR SYSTEM ;STARTUP SECTION OFFSET $008000 CODE XDEF START START: XREF ~~main sei ; Disabled interrupts clc ; clear carry to switch to native mode xce ; Xchange carry & emulation bit. native mode rep #$18 ; Binary mode (decimal mode off), X/Y 16 bit LONGI ON ldx #$1FFF ; set stack to $1FFF txs rep #$30 longa on longi on ; Init data used for heap ; see heap definition below XREF ~~_heap_top XREF ~~_mem_start stz ~~_heap_top stz ~~_mem_start XREF ~~preInit jsr >~~preInit sep #$30 ; X,Y,A are 8 bit numbers LONGA OFF LONGI OFF 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 stz $210E ; Plane 0 scroll y (first 8 bits) stz $210E ; Plane 0 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 $2110 ; Plane 1 scroll y (first 8 bits) stz $2110 ; Plane 1 scroll y (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 $2112 ; Plane 2 scroll y (first 8 bits) stz $2112 ; Plane 2 scroll y (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 stz $2114 ; Plane 3 scroll y (first 8 bits) stz $2114 ; Plane 3 scroll y (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 ;;lda #$01 ;;sta $4200 rep #$30 longa on longi on jsr >~~main brk XDEF IRQ IRQ: ;LONGA ON ;LONGI ON rep #$10 sep #$20 lda #65 sta $3000 rep #$30 ;LONGA OFF ;LONGI OFF rti XREF ~~IRQHandler LONGA ON LONGI ON rep #$30 pha phx phy jsr ~~IRQHandler ply plx pla rti XDEF NMI NMI: rep #$30 lda #66 sta $3000 sep #$30 ; X,Y,A are 8 bit numbers rti XREF ~~NMIHandler LONGA ON LONGI ON rep #$30 pha phx phy phd phb lda #$0000 sep #$30 ; X,Y,A are 8 bit numbers LONGA OFF LONGI OFF lda $4210 ; Read NMI LONGA ON LONGI ON rep #$30 jsr ~~NMIHandler plb pld ply plx pla rti DIRQ: rti ENDS ;****************************************************************************** ;*** Heap definition *** ;****************************************************************************** DATA XDEF ~~heap_start XDEF ~~heap_end ~~heap_start: WORD $1e00 ~~heap_end: WORD $2000 ;****************************************************************************** ;*** SNES ROM Registartion Data *** ;****************************************************************************** REGISTRATION_DATA SECTION MAKER_CODE FCC /FF/ GAME_CODE FCC /SMWJ/ FIXED_VALUE0 BYTE $00, $00, $00, $00, $00, $00, $00 EXPANSION_RAM_SIZE BYTE $00 SPECIAL_VERSION BYTE $00 CARTRIDGE_TYPE_SUB BYTE $00 GAME_TITLE FCC /GAME TITLE !/ ;012345678901234567890; MAP_MODE BYTE $20 CARTRIDGE_SIZE BYTE $00 ROM_SIZE BYTE $09 RAM_SIZE BYTE $00 DESTINATION_CODE BYTE $00 FIXED_VALUE1 BYTE $33 MASK_ROM_VERSION BYTE $00 COMPLEMENT_CHECK BYTE $00, $00 CHEKSUM BYTE $00, $00 ;****************************************************************************** ;*** SNES Interrupts and Reset vector *** ;****************************************************************************** VECTORS SECTION ; Native vector N_COP DW DIRQ N_BRK DW DIRQ N_ABORT DW DIRQ N_NMI DW NMI N_RSRVD DW DIRQ N_IRQ DW IRQ DS 4 ; Emulation vector E_COP DW DIRQ E_RSRVD DW DIRQ E_ABORT DW DIRQ E_NMI DW DIRQ E_RESET DW START E_IRQ DW DIRQ END