First attemp at scrolling text

025.scroll_text/utils.s

@@ -0,0 +1,47 @@
+	include "includes.i"
+	
+	xdef 	WaitVerticalBlank
+	xdef	WaitRaster
+	xdef	Depack
+
+	
+WaitVerticalBlank:	
+	movem.l	d0,-(sp)
+.loop:	move.l	$dff004,d0
+	and.l	#$1ff00,d0
+	cmp.l	#303<<8,d0	; wait for the scan line
+	bne.b	.loop
+.loop2	move.l	$dff004,d0
+	and.l	#$1ff00,d0
+	cmp.l	#303<<8,d0	; wait for the scan line to pass (A4000 is fast!)
+	beq.b	.loop2
+	movem.l (sp)+,d0
+	rts	
+
+
+WaitRaster:		;wait for rasterline d0.w. Modifies d0-d2/a0.
+	movem.l d0-a6,-(sp)
+	move.l #$1ff00,d2
+	lsl.l #8,d0
+	and.l d2,d0
+	lea $dff004,a0
+.wr:	move.l (a0),d1
+	and.l d2,d1
+	cmp.l d1,d0
+	bne.s .wr
+	movem.l (sp)+,d0-a6
+	rts
+
+
+Depack:
+	;a0 = input buffer to be decompressed. Must be 16-bit aligned!
+	;a1 = output buffer. Points to the end of the data at exit
+	movem.l	d0-a6,-(sp)	
+	bsr	doynaxdepack		; decompress data
+	movem.l (sp)+,d0-a6
+	rts
+
+	;; this is one FAST decompression routine!
+	include "../tools/external/doynamite68k/depacker_doynax.asm"
+
+