70 lines
1.1 KiB
ArmAsm
70 lines
1.1 KiB
ArmAsm
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; ******************************************************************
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; * 6502 code example
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; * (c) 01.05.2017 Paolo Iocco
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; *
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; ******************************************************************
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#define ROMSIZE $2000
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#define ORIGIN $E000
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#define VECTORS $FFFA
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; .word ORIGIN ; Memory Base if PRG file
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* = ORIGIN ; Program Counter at ORIGIN (ORG)
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;* ************** *
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;* Code Segment *
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;* ************** *
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Start:
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lda #$aa
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sta $00
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ldx #$00
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loop:
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stx $01
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inx
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jmp loop
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old:
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ldx #$00 ; write message
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Print:
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lda tWelcome,x
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beq Exit
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jsr $ffd2
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inx
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bne Print
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Exit:
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jmp Exit
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; * ************* *
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; * INT Segment *
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; * ************* *
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NMI:
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rti
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BREAK:
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rti
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; * ************** *
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; * Data Segment *
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; * ************** *
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tWelcome:
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.asc " * WELCOME! * "
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.byt $00 ; End of Message
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tEntry:
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.asc "Ready."
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.byt $00 ; End of Message
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Fill:
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.dsb (ORIGIN+ROMSIZE)-6-*,$ff ;fill up to TOPROM with 0xff
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;* ***************** *
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;* Vectors Segment *
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;* ***************** *
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* = VECTORS ; Program Counter at ORIGIN (ORG)
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.word NMI
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.word Start
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.word BREAK
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