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[/] [lattice6502/] [ghdl/] [usrcode.asm] - Blame information for rev 2

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Line No. Rev Author Line
1 2 stanley82 
;
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        cpu 6502
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PAGE 40,120
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;       ****************************************************************************************
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;       This is intended to be the template for the user code
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;       ****************************************************************************************
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*       =       $290    ;user code starts at $290
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return  equ     $fff6   ;jump to fcoo to return control and restart
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sendtxt equ     $fff0
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hex2txt equ     $fff3
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main    ldy     #$55
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        ldx     #$aa
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        lda     #$7e
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        clc
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        adc     #$6     ;9-3=6 carry=0
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        php
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        pha
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        txa
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        pha
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        tya
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        pha
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        lda     #"Y"    ;Display Y register
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        pla
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        jsr     hex2txt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"X"    ;Display X register
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        pla
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        jsr     hex2txt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"A"    ;Display A register
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        pla
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        jsr     hex2txt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"C"    ;Display carry
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        plp
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        php
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        bcc     clear1
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        lda     #"1"
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        jmp     cont1
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clear1  lda     #"0"
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cont1   jsr     sendtxt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"V"    ;Display overflow
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        plp
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        php
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        bvc     clear2
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        lda     #"1"
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        jmp     cont2
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clear2  lda     #"0"
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cont2   jsr     sendtxt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"Z"    ;Display zero
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        plp
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        php
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        beq     clear3
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        lda     #"1"
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        jmp     cont3
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clear3  lda     #"0"
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cont3   jsr     sendtxt
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        lda     #" "
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        jsr     sendtxt
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        lda     #"M"    ;Display minus
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        jsr     sendtxt
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        lda     #"="
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        jsr     sendtxt
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        plp
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        bpl     clear4
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        lda     #"1"
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        jmp     cont4
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clear4  lda     #"0"
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cont4   jsr     sendtxt
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        lda     #"\r"
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        jsr     sendtxt
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        jmp     (return)
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;       end of program

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