mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 00:29:31 +00:00
53dd513176
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
69 lines
1.2 KiB
ArmAsm
69 lines
1.2 KiB
ArmAsm
;
|
|
; Ullrich von Bassewitz, 06.08.1998
|
|
;
|
|
; char cgetc (void);
|
|
;
|
|
|
|
.export _cgetc
|
|
.import cursor
|
|
|
|
.include "pet.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
|
|
|
|
; Fetch the character from the keyboard buffer
|
|
|
|
L3: sei
|
|
ldy KEY_BUF
|
|
ldx #$00
|
|
L4: lda KEY_BUF+1,x
|
|
sta KEY_BUF,x
|
|
inx
|
|
cpx KEY_COUNT
|
|
bne L4
|
|
dec KEY_COUNT
|
|
cli
|
|
ldx #$00 ; Clear high byte
|
|
tya
|
|
rts
|
|
|
|
; Switch the cursor on or off
|
|
|
|
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
|
|
crs8: lda #0
|
|
sta CURS_STATE ; Cursor not displayed
|
|
crs9: rts
|
|
|
|
seton: lda #0
|
|
sta CURS_FLAG
|
|
rts
|
|
|