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29 lines
727 B
ArmAsm
29 lines
727 B
ArmAsm
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; 2020-07-12, Oliver Schmidt
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; char cpeekc (void);
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;
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.export _cpeekc
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.include "apple2.inc"
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_cpeekc:
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ldy CH
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.ifdef __APPLE2ENH__
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bit RD80VID ; In 80 column mode?
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bpl peek ; No, just go ahead
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tya
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lsr ; Div by 2
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tay
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bcs peek ; Odd cols are in main memory
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bit HISCR ; Assume SET80COL
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.endif
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peek: lda (BASL),Y ; Get character
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.ifdef __APPLE2ENH__
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bit LOWSCR ; Doesn't hurt in 40 column mode
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.endif
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eor #$80 ; Invert high bit
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ldx #$00
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rts
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