80 lines
1.9 KiB
Plaintext
80 lines
1.9 KiB
Plaintext
; This file is part of the snescom-asm demo - a demo of how to build a SNES program.
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; See http://bisqwit.iki.fi/source/snescom.html for details.
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; Begin assembling to this address.
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*= $C0FF00
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RESET:
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sei
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clc
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xce
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rep #$20 : .al
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lda #$1fff
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tcs
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jmp @GAME_MAIN
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NMI_16bit:
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php
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rep #$30 : .al : .xl
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pha: phx: phy: phd: phb
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jsl @NMI_ROUTINE
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rep #$30 : .al : .xl
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int_exit:
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plb: pld: ply: plx: pla
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plp
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rti
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IRQ_16bit:
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php
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rep #$30 : .al : .xl
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pha: phx: phy: phd: phb
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jsl @IRQ_ROUTINE
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rep #$30 : .al : .xl
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bra int_exit
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;error vectors
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ABT_8bit: ABT_16bit:
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BRK_8bit: BRK_16bit:
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COP_8bit: COP_16bit:
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IRQ_8bit:
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NMI_8bit:
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- wai: lda $ABCDEF : bra -
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*= $C0FFB0
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; Zero the area from $FFB0 - $FFFF
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; to ensure that the linker won't get clever
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; and fill it with small pieces of code.
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.word 0,0,0,0, 0,0,0,0
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.word 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0
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.word 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0
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*= $C0FFB0
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.byt "MR" ;2 bytes - company id
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.byt "SNSD" ;4 bytes - rom id
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*= $C0FFC0
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.byt "SD2SNES MAIN MENU "
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;123456789012345678901; - max 21 chars
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*= $C0FFD5 .byt $31 ;rom speed
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*= $C0FFD6 .byt $02 ;rom type
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*= $C0FFD7 .byt $06 ;rom size 64 kByte
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*= $C0FFD8 .byt $03 ;sram size 8 kBit
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*= $C0FFD9 .byt $09 ;rom region 4 = Finland
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*= $C0FFDA .byt $33 ;company id flag
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*= $C0FFDC .word 0,0 ;checksums
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*= $C0FFE4 .word COP_16bit
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*= $C0FFE6 .word BRK_16bit
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*= $C0FFE8 .word ABT_16bit
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*= $C0FFEA .word NMI_16bit
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*= $C0FFEE .word IRQ_16bit
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*= $C0FFF4 .word COP_8bit
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*= $C0FFF8 .word ABT_8bit
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*= $C0FFFA .word NMI_8bit
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*= $C0FFFC .word RESET
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*= $C0FFFE .word BRK_8bit
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*= $C0FFFE .word IRQ_8bit
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