mirror of
https://github.com/fumiama/c64-snake.git
synced 2026-06-05 00:32:39 +08:00
23 lines
319 B
NASM
23 lines
319 B
NASM
.data zp
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.space _na 1 ; a的临时存放处
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.text
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printbyte:
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php
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pha
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sta _na
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txa
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pha
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ldx #8 ; 打印8bit
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* lda #$30 ; a = '0'
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asl _na ; 左移一位，溢出到c
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adc #0 ; a = a + c + 0
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jsr chrout ; putchar(a)
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dex ; x--
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bne - ; if(x != 0) goto 上个星号
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lda #$20
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jsr chrout
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pla
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tax
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pla
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plp
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rts |