mirror of
https://github.com/cc65/cc65.git
synced 2024-11-05 08:05:51 +00:00
44 lines
849 B
ArmAsm
44 lines
849 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 22.09.1998
|
|
;
|
|
; void clrscr (void);
|
|
;
|
|
|
|
.export _clrscr
|
|
.import plot
|
|
.import CURS_X: zp, CURS_Y: zp, CharPtr: zp
|
|
|
|
.include "cbm610.inc"
|
|
|
|
.proc _clrscr
|
|
|
|
lda #0
|
|
sta CURS_X
|
|
sta CURS_Y
|
|
jsr plot ; Set cursor to top left corner
|
|
|
|
lda IndReg
|
|
pha
|
|
lda #$0F
|
|
sta IndReg ; Switch to the system bank
|
|
|
|
ldx #8
|
|
ldy #$00
|
|
lda #$20 ; Screencode for blank
|
|
L1: sta (CharPtr),y
|
|
iny
|
|
bne L1
|
|
inc CharPtr+1
|
|
dex
|
|
bne L1
|
|
|
|
pla
|
|
sta IndReg ; Restore old indirect segment
|
|
|
|
jmp plot ; Set screen pointer again
|
|
|
|
.endproc
|
|
|
|
|
|
|