mirror of
https://github.com/cc65/cc65.git
synced 2024-11-04 17:04:58 +00:00
50 lines
997 B
ArmAsm
50 lines
997 B
ArmAsm
|
;
|
||
|
|
; Ullrich von Bassewitz, 06.08.1998
|
||
|
|
;
|
||
|
|
; char cgetc (void);
|
||
|
|
;
|
||
|
|
|
||
|
|
.export _cgetc
|
||
|
|
.import plot, write_crtc
|
||
|
|
.import cursor
|
||
|
|
|
||
|
|
.include "zeropage.inc"
|
||
|
|
.include "page3.inc"
|
||
|
|
|
||
|
|
|
||
|
|
_cgetc: lda KeyIndex ; Get number of characters
|
||
|
|
bne L2 ; Jump if there are already chars waiting
|
||
|
|
|
||
|
|
; Switch on the cursor if needed
|
||
|
|
|
||
|
|
lda cursor
|
||
|
|
beq L1 ; Jump if no cursor
|
||
|
|
|
||
|
|
jsr plot ; Set the current cursor position
|
||
|
|
ldy #10
|
||
|
|
lda Config ; Cursor format
|
||
|
|
jsr write_crtc ; Set the cursor formar
|
||
|
|
|
||
|
|
L1: lda KeyIndex
|
||
|
|
beq L1
|
||
|
|
|
||
|
|
ldy #10
|
||
|
|
lda #$20 ; Cursor off
|
||
|
|
jsr write_crtc
|
||
|
|
|
||
|
|
L2: ldx #$00 ; Get index
|
||
|
|
ldy KeyBuf ; Get first character in the buffer
|
||
|
|
sei
|
||
|
|
L3: lda KeyBuf+1,x ; Move up the remaining chars
|
||
|
|
sta KeyBuf,x
|
||
|
|
inx
|
||
|
|
cpx KeyIndex
|
||
|
|
bne L3
|
||
|
|
dec KeyIndex
|
||
|
|
cli
|
||
|
|
|
||
|
|
ldx #$00 ; High byte
|
||
|
|
tya ; First char from buffer
|
||
|
|
rts
|
||
|
|
|