cc65/libsrc/atari7800/clrscr.s

40 lines
783 B
ArmAsm

.include "atari7800.inc"
.export _clrscr
.import _screen
.import pusha0,pushax
.include "extzp.inc"
.code
.proc _clrscr
lda #<_screen
ldx #>_screen
sta ptr7800
stx ptr7800+1
ldx #screenrows
@L1: ldy #charsperline
lda #0
@L2: sta (ptr7800),y
dey
bne @L2
lda ptr7800
clc
adc #charsperline
bcc @L3
inc ptr7800+1
@L3: dex
bne @L1
rts
.endproc
;-------------------------------------------------------------------------------
; force the init constructor to be imported
.import initconio
conio_init = initconio