X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libsrc%2Fatari%2Fscroll.s;h=5e8428cc2146eab6cce7e879604afb15900f44ae;hb=c642dab36f467e49fedbcf6aa47f2cdb1b74a09e;hp=7aa37876d3229d65af8dc1e1f08b1d3ebfac1511;hpb=668c031c32fc8d3690c3e9500643d4bf7f3232f5;p=cc65

diff --git a/libsrc/atari/scroll.s b/libsrc/atari/scroll.s
index 7aa37876d..5e8428cc2 100644
--- a/libsrc/atari/scroll.s
+++ b/libsrc/atari/scroll.s
@@ -1,164 +1,164 @@
 ;
-; Christian Groessler, June 2000
+; Christian Groessler, June 2004
 ;
-; void __fastcall__ scroll (signed char numlines);
+; void __fastcall__ _scroll (signed char numlines);
 ; numlines > 0  scrolls up
 ; numlines < 0  scrolls down
 ;
 
-	.include	"atari.inc"
-	.importzp	tmp1,tmp4,ptr1,ptr2
-	.import		mul40,_clrscr
-	.export		_scroll
+        .include        "atari.inc"
+        .importzp       tmp1,tmp4,ptr1,ptr2
+        .import         mul40,_clrscr
+        .export         __scroll
 
-.proc	_scroll
+.proc   __scroll
 
-	cmp	#0
-	beq	jmpfin
-;	cmp	#$80
-;	bcc	up
-	bpl	up
+        cmp     #0
+        beq     jmpfin
+;       cmp     #$80
+;       bcc     up
+        bpl     up
 
 ;scroll down
-	eor	#$ff
-	clc
-	adc	#1		; make positive
-	sta	tmp1
-
-	cmp	#24		; scroll >= the whole screen?
-	bcc	down_ok
-	jmp	_clrscr
-
-down_ok:lda	SAVMSC
-	clc
-	adc	#<(40*23)
-	sta	ptr1
-	sta	ptr2
-	lda	SAVMSC+1
-	adc	#>(40*23)
-	sta	ptr1+1		; point to last line on screen
-	sta	ptr2+1
-
-	lda	tmp1
-	jsr	mul40
-	sta	tmp4
-	lda	ptr2
-	sec
-	sbc	tmp4
-	sta	ptr2
-	stx	tmp4
-	lda	ptr2+1
-	sbc	tmp4
-	sta	ptr2+1
-
-	lda	#24		; # of lines on screen
-	sec
-	sbc	tmp1		; # of lines to move
-	tax
-
-	;very simple, could be improved
-
-scrold:	ldy	#39		; # of chars on a line - 1
-copy_d:	lda	(ptr2),y
-	sta	(ptr1),y
-	dey
-	bpl	copy_d
-	lda	ptr1
-	sec
-	sbc	#40
-	sta	ptr1
-	bcs	u1
-	dec	ptr1+1
-u1:	lda	ptr2
-	sec
-	sbc	#40
-	sta	ptr2
-	bcs	u2
-	dec	ptr2+1
-u2:	dex
-	bne	scrold
-
-	; fill new scrolled in lines with space
-
-	ldx	tmp1		; # of new lines
-fild:	lda	#0
-	ldy	#39
-fill_d:	sta	(ptr1),y
-	dey
-	bpl	fill_d
-	dex
-jmpfin:	beq	finish
-	lda	ptr1
-	sec
-	sbc	#40
-	sta	ptr1
-	bcs	u3
-	dec	ptr1+1
-u3:	jmp	fild
+        eor     #$ff
+        clc
+        adc     #1              ; make positive
+        sta     tmp1
+
+        cmp     #24             ; scroll >= the whole screen?
+        bcc     down_ok
+        jmp     _clrscr
+
+down_ok:lda     SAVMSC
+        clc
+        adc     #<(40*23)
+        sta     ptr1
+        sta     ptr2
+        lda     SAVMSC+1
+        adc     #>(40*23)
+        sta     ptr1+1          ; point to last line on screen
+        sta     ptr2+1
+
+        lda     tmp1
+        jsr     mul40
+        sta     tmp4
+        lda     ptr2
+        sec
+        sbc     tmp4
+        sta     ptr2
+        stx     tmp4
+        lda     ptr2+1
+        sbc     tmp4
+        sta     ptr2+1
+
+        lda     #24             ; # of lines on screen
+        sec
+        sbc     tmp1            ; # of lines to move
+        tax
+
+        ;very simple, could be improved
+
+scrold: ldy     #39             ; # of chars on a line - 1
+copy_d: lda     (ptr2),y
+        sta     (ptr1),y
+        dey
+        bpl     copy_d
+        lda     ptr1
+        sec
+        sbc     #40
+        sta     ptr1
+        bcs     u1
+        dec     ptr1+1
+u1:     lda     ptr2
+        sec
+        sbc     #40
+        sta     ptr2
+        bcs     u2
+        dec     ptr2+1
+u2:     dex
+        bne     scrold
+
+        ; fill new scrolled in lines with space
+
+        ldx     tmp1            ; # of new lines
+fild:   lda     #0
+        ldy     #39
+fill_d: sta     (ptr1),y
+        dey
+        bpl     fill_d
+        dex
+jmpfin: beq     finish
+        lda     ptr1
+        sec
+        sbc     #40
+        sta     ptr1
+        bcs     u3
+        dec     ptr1+1
+u3:     jmp     fild
 
 ;scroll up
-up:	sta	tmp1		; # of lines to scroll
-	cmp	#24		; scroll >= the whole screen?
-	bcc	up_ok
-	jmp	_clrscr
-
-	;multiply by 40 (xsize)
-up_ok:	jsr	mul40
-	clc
-	adc	SAVMSC		; add start of screen mem
-	sta	ptr2
-	txa
-	adc	SAVMSC+1
-	sta	ptr2+1
-	lda	SAVMSC+1
-	sta	ptr1+1
-	lda	SAVMSC
-	sta	ptr1
-	lda	#24		; # of lines on screen
-	sec
-	sbc	tmp1		; # of lines to move
-	tax
-
-	;very simple, could be improved
-
-scroll:	ldy	#39		; # of chars on a line - 1
-copy_l:	lda	(ptr2),y
-	sta	(ptr1),y
-	dey
-	bpl	copy_l
-	lda	#40
-	clc
-	adc	ptr1
-	sta	ptr1
-	bcc	l1
-	inc	ptr1+1
-l1:	lda	#40
-	clc
-	adc	ptr2
-	sta	ptr2
-	bcc	l2
-	inc	ptr2+1
-l2:	dex
-	bne	scroll
-
-	; fill new scrolled in lines with space
-
-	ldx	tmp1		; # of new lines
-fill:	lda	#0
-	ldy	#39
-fill_l:	sta	(ptr1),y
-	dey
-	bpl	fill_l
-	dex
-	beq	finish
-	lda	#40
-	clc
-	adc	ptr1
-	sta	ptr1
-	bcc	l3
-	inc	ptr1+1
-l3:	jmp	fill
-
-finish:	rts
+up:     sta     tmp1            ; # of lines to scroll
+        cmp     #24             ; scroll >= the whole screen?
+        bcc     up_ok
+        jmp     _clrscr
+
+        ;multiply by 40 (xsize)
+up_ok:  jsr     mul40
+        clc
+        adc     SAVMSC          ; add start of screen mem
+        sta     ptr2
+        txa
+        adc     SAVMSC+1
+        sta     ptr2+1
+        lda     SAVMSC+1
+        sta     ptr1+1
+        lda     SAVMSC
+        sta     ptr1
+        lda     #24             ; # of lines on screen
+        sec
+        sbc     tmp1            ; # of lines to move
+        tax
+
+        ;very simple, could be improved
+
+scroll: ldy     #39             ; # of chars on a line - 1
+copy_l: lda     (ptr2),y
+        sta     (ptr1),y
+        dey
+        bpl     copy_l
+        lda     #40
+        clc
+        adc     ptr1
+        sta     ptr1
+        bcc     l1
+        inc     ptr1+1
+l1:     lda     #40
+        clc
+        adc     ptr2
+        sta     ptr2
+        bcc     l2
+        inc     ptr2+1
+l2:     dex
+        bne     scroll
+
+        ; fill new scrolled in lines with space
+
+        ldx     tmp1            ; # of new lines
+fill:   lda     #0
+        ldy     #39
+fill_l: sta     (ptr1),y
+        dey
+        bpl     fill_l
+        dex
+        beq     finish
+        lda     #40
+        clc
+        adc     ptr1
+        sta     ptr1
+        bcc     l3
+        inc     ptr1+1
+l3:     jmp     fill
+
+finish: rts
 
 .endproc