28 lines
603 B
ArmAsm
28 lines
603 B
ArmAsm
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.define Mprint
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.sect .text
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.sect .rom
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.sect .data
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.sect .bss
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.sect .text
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! This subroutine prints a zero terminated ascii string.
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! The registerpair AX contains the start of the string.
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! The subroutine WRCH is a special routine on the BBC microcomputer
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! which prints the character in A to the screen.
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! The subroutine WRCH is a special one provided by the BBC
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! microcomputer.
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Mprint:
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stx ADDR ! start address of string (lowbyte)
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sta ADDR+1 ! start address of string (highbyte)
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ldy #0
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1: lda (ADDR),y ! get ascii character
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beq 2f
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jsr WRCH ! put it on the screen
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iny
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bne 1b
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2: rts
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