22 lines
654 B
Text
22 lines
654 B
Text
; goodbyeworld.s for C= 8-bit machines, ca65 assembler format.
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; String printing limited to strings of 256 characters or less.
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a_cr = $0d ; Carriage return.
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bsout = $ffd2 ; C64 KERNEL ROM, output a character to current device.
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; use $fded for Apple 2, $ffe3 (ascii) or $ffee (raw) for BBC.
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.code
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ldx #0 ; Starting index 0 in X register.
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printnext:
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lda text,x ; Get character from string.
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beq done ; If we read a 0 we're done.
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jsr bsout ; Output character.
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inx ; Increment index to next character.
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bne printnext ; Repeat if index doesn't overflow to 0.
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done:
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rts ; Return from subroutine.
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.rodata
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text:
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.byte "Hello world!", a_cr, 0
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