2020-01-02 17:57:03 +00:00
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; isascii.s
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;
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; This file is part of
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; cc65 - a freeware C compiler for 6502 based systems
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;
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2020-02-02 17:21:25 +00:00
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; https://cc65.github.io
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2020-01-02 17:57:03 +00:00
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;
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; See "LICENSE" file for legal information.
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;
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; int isascii (int c);
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;
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.export _isascii
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_isascii:
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2020-02-02 17:21:25 +00:00
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asl a ; high-bit to carry
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txa ; check range of input param
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bne @L1 ; out-of bounds?
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adc #$FF ; calculate return value based on carry
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2020-01-02 17:57:03 +00:00
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rts
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2020-01-05 14:57:44 +00:00
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@L1: lda #$00 ; return false
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2020-01-02 17:57:03 +00:00
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tax
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rts
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