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;
; Ullrich von Bassewitz, 06.08.1998
;
; char cgetc (void);
;
.export _cgetc
.import cursor
.include "cbm_kernal.inc"
.include "vic20.inc"
_cgetc: lda KEY_COUNT ; Get number of characters
bne L3 ; Jump if there are already chars waiting
; Switch on the cursor if needed
lda CURS_FLAG
pha
lda cursor
jsr setcursor
L1: lda KEY_COUNT
beq L1
ldx #0
pla
bne L2
inx
L2: txa
jsr setcursor
L3: jsr KBDREAD ; Read char and return in A
ldx #0
rts
; Switch the cursor on or off
.proc setcursor
tax ; On or off?
bne seton ; Go set it on
lda CURS_FLAG ; Is the cursor currently off?
bne crs9 ; Jump if yes
inc CURS_FLAG ; Mark it as off
lda CURS_STATE ; Cursor currently displayed?
beq crs8 ; Jump if no
ldy CURS_X ; Get the character column
lda (SCREEN_PTR),y ; Get character
eor #$80
sta (SCREEN_PTR),y ; Store character back
lda CURS_COLOR
sta (CRAM_PTR),y ; Store color back
crs8: lda #0
sta CURS_STATE ; Cursor not displayed
crs9: rts
seton: lda #0
sta CURS_FLAG
rts
.endproc
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