1
0
mirror of https://github.com/cc65/cc65.git synced 2024-11-02 03:04:31 +00:00
cc65/libsrc/c64/cgetc.s
uz 53dd513176 This commit was generated by cvs2svn to compensate for changes in r2,
which included commits to RCS files with non-trunk default branches.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00

62 lines
1.1 KiB
ArmAsm

;
; Ullrich von Bassewitz, 06.08.1998
;
; char cgetc (void);
;
.export _cgetc
.import cursor
.include "c64.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
lda #1
sta 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