67 lines
1.3 KiB
ArmAsm
67 lines
1.3 KiB
ArmAsm
;
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; Ullrich von Bassewitz, 2003-04-13
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;
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; char cgetc (void);
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;
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.export _cgetc
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.constructor cursoroff
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.destructor cursoron
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.import cursor
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.include "atmos.inc"
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; ------------------------------------------------------------------------
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;
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.proc _cgetc
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lda KEYBUF ; Do we have a character?
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bmi @L2 ; Yes: Get it
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; No character, enable cursor and wait
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lda cursor ; Cursor currently off?
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beq @L1 ; Skip if so
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jsr cursoron
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@L1: lda KEYBUF
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bpl @L1
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; If the cursor was enabled, disable it now
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ldx cursor
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beq @L3
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dec STATUS ; Clear bit zero
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; We have the character, clear avail flag
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@L2: and #$7F ; Mask out avail flag
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sta KEYBUF
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; Done
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@L3: ldx #$00
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rts
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.endproc
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; ------------------------------------------------------------------------
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; Switch the cursor on
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cursoron:
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lda STATUS
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ora #%00000001
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sta STATUS
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rts
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; ------------------------------------------------------------------------
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; Switch the cursor off
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cursoroff:
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lda STATUS
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and #%11111110
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sta STATUS
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rts
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