section merry-xmas,code_c	; Put into chip memory
 	opt 	c-,o+			; No case sensitivity, Optimize on


 	lea 	gfxlib,a1
 	moveq 	#0,d0
 	move.l  4.w,a6
 	jsr 	-$228(a6) 		; Open Graphics library
 	tst 	d0
 	beq 	error
 	move.l  D0,gfxbse
 
					; generate snow-fields
	lea 	sprite0,a0	
	move.l 	#$2c002d00,d0		; first longword
	moveq 	#69,d1			; 60 sprites
spr0lp	swap	d0
	move.b 	$dff007,d2
	eor.b 	d2,d0
	swap 	d0
	
	mulu d3,d3	
	mulu d3,d3
	mulu d3,d3
	mulu d3,d3

	move.l d0,(a0)+
	move.l #$10000,(a0)+
	add.l #$02000200,d0	
	dbra d1,spr0lp	

	move.l #sprite0,d0
	move.w d0,sp0l
	swap d0
	move.w d0,sp0h

				
	lea 	sprite1,a0	
	move.l 	#$2d002e00,d0		; first longword
	moveq 	#69,d1			; 60 sprites
spr1lp	swap	d0
	move.b 	$dff007,d2
	eor.b 	d2,d0
	swap 	d0
	
	mulu d3,d3	
	mulu d3,d3
	mulu d3,d3
	mulu d3,d3

	move.l d0,(a0)+
	move.l #$10000,(a0)+
	add.l #$03000300,d0	
	dbra d1,spr1lp	

	move.l #sprite1,d0
	move.w d0,sp1l
	swap d0
	move.w d0,sp1h

	lea 	sprite2,a0	
	move.l 	#$2c002d00,d0		; first longword
	moveq 	#69,d1			; 60 sprites
spr2lp	swap	d0
	move.b 	$dff007,d2
	eor.b 	d2,d0
	swap 	d0
	
	mulu d3,d3	
	mulu d3,d3
	mulu d3,d3
	mulu d3,d3

	move.l d0,(a0)+
	move.l #$10000,(a0)+
	add.l #$02000200,d0	
	dbra d1,spr2lp	

	move.l #sprite2,d0
	move.w d0,sp2l
	swap d0
	move.w d0,sp2h

				
	lea 	sprite3,a0	
	move.l 	#$2d002e00,d0		; first longword
	moveq 	#69,d1			; 60 sprites
spr3lp	swap	d0
	move.b 	$dff007,d2
	eor.b 	d2,d0
	swap 	d0
	
	mulu d3,d3	
	mulu d3,d3
	mulu d3,d3
	mulu d3,d3

	move.l d0,(a0)+
	move.l #$10000,(a0)+
	add.l #$03000300,d0	
	dbra d1,spr3lp	

	move.l #sprite3,d0
	move.w d0,sp3l
	swap d0
	move.w d0,sp3h

 	move.l  #logo,d0		; Store screen address in
 	move.w  d0,pl0l			; Copper list
 	swap    d0
 	move.w  d0,pl0h
	swap	d0
	add.l 	#3920,d0
	move.w 	d0,pl1l
	swap	d0
	move.w	d0,pl1h
	swap 	d0
	add.l 	#3920,d0
	move.w 	d0,pl2l
	swap	d0
	move.w	d0,pl2h
	swap 	d0
	add.l 	#3920,d0
	move.w 	d0,pl3l
	swap	d0
	move.w	d0,pl3h
	swap 	d0
	add.l	#3920,d0

	
	lea topcols,a1
	move.l d0,a0
	move.w #$180,d0
	moveq #15,d1
toplp	move.w d0,(a1)+
	move.w (a0)+,(a1)+
	addq.w #2,d0
	dbra d1,toplp

 
 	move.l  #piccy,d0		; Store screen address in
 	move.w  d0,mp0l			; Copper list
 	swap    d0
 	move.w  d0,mp0h
	swap	d0
	add.l 	#6440,d0
	move.w 	d0,mp1l
	swap	d0
	move.w	d0,mp1h
	swap 	d0
	add.l 	#6440,d0
	move.w 	d0,mp2l
	swap	d0
	move.w	d0,mp2h
	swap 	d0
	add.l 	#6440,d0
	move.w 	d0,mp3l
	swap	d0
	move.w	d0,mp3h
	swap 	d0
	add.l	#6440,d0
	move.w 	d0,mp4l
	swap 	d0
	move.w	d0,mp4h
	swap	d0
	add.l 	#6440,d0

	
	lea botcols,a1
	move.l d0,a0
	move.w #$180,d0
	moveq #31,d1
botlp	move.w d0,(a1)+
	move.w (a0)+,(a1)+
	addq.w #2,d0
	dbra d1,botlp


 	move.l  gfxbse,a6		; Set up copper list
 	add.l	#$32,a6
 	move.w  #$80,$dff096
 	move.l  (a6),oldcpr
 	move.l  #newcpr,(a6)
 	move.w  #$8080,$dff096
 	move.w  #$8010,$dff09a
 	move.l  $6c.w,old
 	move.l  #new,$6c.w

WAIT:	btst	#6,$bfe001		; Test for left mousebutton
 	bne.s 	wait

 	move.l  old,$6c.w		; Return to workbench
 	move.l  gfxbse,a6		; copper list
 	add.l	#$32,a6
 	move.w	#$0080,$dff096
 	move.l  oldcpr,(a6)
 	move.w  #$8080,$dff096
	
	move.l	gfxbse,a1		; Close graphics library
	move.l  $4.w,a6
	jsr 	-$19e(a6)

error: 	clr.l  d0			; exit routine
 	rts

new: 	movem.l d0-d7/a0-a6,-(sp)	; save all registers
 	and.w 	#$10,$dff01e        	; check if it is 
 	beq.s 	out
 	move.w 	#$10,$dff09c

	bsr starmov

	bsr scroll

out:	movem.l (sp)+,d0-d7/a0-a6
 	dc.w 	$4ef9			; jsr instruction
old: 	dc.l 	0			


prnchr: lea 	font,a0
	lea 	logo+40,a1			; destination
	sub.b 	#32,d0			; de-ascii
	mulu 	#512,d0			; find position in font
	add.l 	d0,a0
	moveq 	#3,d1
lp1	moveq 	#31,d2
	move.l 	a1,a2
lp2	move.l	(a0)+,(a2)
	add.l #44,a2
	dbra d2,lp2
	add.l #3920,a1
	dbra d1,lp1
	rts

SCROLL	cmp.b #0,scrlctd
	beq.s scrl2
	subq.b #1,scrlctd
	rts
scrl2	bsr blitscr
	move.b scrlptr,d0
	subq.b #1,d0
	beq.s zero
 	move.b d0,scrlptr
	rts
zero	move.b #8,scrlptr
	move.l txtptr,a0
	moveq #0,d0
	move.b (a0)+,d0
	cmp.b #0,d0
 	bne.s charok
	move.l #text,txtptr
	bra.s zero
charok	cmp.b #254,d0
	bne.s notpuse
	move.b #80,scrlctd
	move.l a0,txtptr
	moveq #32,d0
	bsr prnchr
	rts
notpuse move.l a0,txtptr
	bsr prnchr
	rts	



blitscr	
	moveq 	#3,d0
	lea 	logo,a0

blitlp	btst 	#14,$dff002
	bne.s 	blitlp
	move.l 	a0,$dff050
	move.l 	a0,a1
	subq.l 	#2,a1
	move.l 	a1,$dff054
	clr.l 	$dff064
	move.l 	#-1,$dff044
	move.w 	#%1101100111110000,$dff040
	clr.w	$dff042
	move.w	#22+33*64,$dff058
	add.l 	#3920,a0
	dbra d0,blitlp
blitfin	btst 	#14,$dff002
	bne.s	blitfin	
	rts


starmov	bsr  	move0
	bsr 	move1
	bsr 	move2
	bsr 	move3
	rts

move0	lea sprite0+69*8,a0
	moveq #68,d0
	move.b 1(a0),saveval
mv0lp	move.b -7(a0),1(a0)
	subq.l #8,a0
	dbra d0,mv0lp
	move.b	saveval,d0
	move.b $dff007,d1
	eor.b d1,d0	
	move.b d0,1(a0)
	rts

move1	lea sprite1+69*8,a0
	moveq #68,d0
	move.b 1(a0),saveval
mv1lp	move.b -7(a0),1(a0)
	subq.l #8,a0
	dbra d0,mv1lp
	move.b	saveval,d0
	move.b $dff007,d1
	eor.b d1,d0	
	move.b d0,1(a0)
	rts


move2	lea sprite2+69*8,a0
	moveq #68,d0
	move.b 1(a0),saveval
mv2lp	move.b -7(a0),1(a0)
	subq.l #8,a0
	dbra d0,mv2lp
	move.b	saveval,d0
	move.b $dff007,d1
	eor.b d1,d0	
	move.b d0,1(a0)
	rts

move3	lea sprite3+69*8,a0
	moveq #68,d0
	move.b 1(a0),saveval
mv3lp	move.b -7(a0),1(a0)
	subq.l #8,a0
	dbra d0,mv3lp
	move.b	saveval,d0
	move.b $dff007,d1
	eor.b d1,d0	
	move.b d0,1(a0)
	rts


saveval	dc.b 	0
scrlptr	dc.b	6
scrlctd	dc.b	0
	even
txtptr	dc.l 	text
text	dc.b 	" IT'S KRISTMAS TIME!,",254," AND TIME FOR A FAIRLY SEASONAL AMIGA COMPUTING DEMO. "
	;	 0123456789
	dc.b	"  AMIGA!  ",254
	dc.b    " FIRSTLY I "
	DC.B 	"MUST APOLOGISE TO MY FAN FOR NOT DOING A DEMO LAST MONTH, BUT THINGS GOT TOO BUSY! SORRY! "
	dc.b 	"     SPECIAL MESSAGES AND ADVERTISMENTS....  HAVE YOU GOT A MODEM? PHONE THE BEST BBS IN THE WHOLE "
	DC.B 	"WORLD, MAX!  PHONE MAX ON (0905) 52536/56610/57822/754127/754151 NOW!   ALL SPEEDS FROM 300 BAUD (SLOOOOOOW) "
	DC.B 	"TO MEGA-SUPER-DOOPER FAST 19.2K BAUD WITH HST AND MNP LEVEL 5 ERROR CORRECTION (LOG ON AND SAY - I SAW THIS ADVERT "
	DC.B 	" GET ON AND BOOGY DOWN TO THE HOTTEST BOARD THIS SIDE OF THE UKRAINE. "
	dc.b 	" SORRY TO MARK FOR FORGETTING YOU IN THE LAST DEMO. ERM. SORRY I'VE FORGOTTEN WHAT YOU ASKED ME TO SAY.  PERHAPS "
	DC.B 	"THE NEXT ONE.  ",0  
	DC.B 	"OH YES, THE CREDITS... CODE CODED BY THE ONE AND ONLY (EXCEPT FOR ALL THE OTHERS) ---- JOLYON RALPH ----   "
	DC.B 	"MOST GRAPHICS BY THE MY GOOD OLE BUDDY ---- RUSS WARK ----  WATCH OUT FOR HIS WEIRD CARTOONS IN THE MAGAZINE - SMUT - "
	DC.B 	0

oldcpr: dc.l	0			; Workbench copperlist
newcpr:	dc.w 	$100,$4200,$102,$0,$104,0,$108,4,$10a,4
 	dc.w 	$92,$38,$94,$d0,$8e,$2c81,$90,$2cc1,$e0
pl0h: 	dc.w	0,$e2
pl0l: 	dc.w	0,$e4
pl1h: 	dc.w 	0,$e6
pl1l: 	dc.w	0,$e8
pl2h:	dc.w	0,$ea
pl2l: 	dc.w	0,$ec
pl3h:	dc.w	0,$ee	
pl3l:	dc.w	0,$120
sp0h:	dc.w	0,$122
sp0l:	dc.w	0,$124
sp1h:	dc.w	0,$126
sp1l:	dc.w	0,$128
sp2h:	dc.w	0,$12a
sp2l:	dc.w	0,$12c
sp3h:	dc.w	0,$12e
sp3l:	dc.w	0
topcols	ds.w	32
	dc.w	$180,0,$182,0


	dc.w $3009,$fffe,$186,$1
	dc.w $3109,$fffe,$186,$2
	dc.w $3209,$fffe,$186,$3
	dc.w $3309,$fffe,$186,$4
	dc.w $3409,$fffe,$186,$5
	dc.w $3509,$fffe,$186,$6
	dc.w $3609,$fffe,$186,$7
	dc.w $3709,$fffe,$186,$8
	dc.w $3809,$fffe,$186,$9
	dc.w $3909,$fffe,$186,$a

	dc.w $4109,$fffe,$186,$1a
	dc.w $4209,$fffe,$186,$3a
	dc.w $4309,$fffe,$186,$4a
	dc.w $4409,$fffe,$186,$5a
	dc.w $4509,$fffe,$186,$6a
	dc.w $4609,$fffe,$186,$7a
	dc.w $4709,$fffe,$186,$8a
	dc.w $4809,$fffe,$186,$9a
	dc.w $4909,$fffe,$186,$aa


	dc.w $7709,$fffe,$108,0,$10a,0,$104,$a

	dc.w $7809,$fffe,$100,$5200
	dc.w $e0
mp0h	dc.w 0,$e2
mp0l	dc.w 0,$e4
mp1h	dc.w 0,$e6
mp1l 	dc.w 0,$e8
mp2h	dc.w 0,$ea
mp2l	dc.w 0,$ec
mp3h	dc.w 0,$ee
mp3l	dc.w 0,$f0
mp4h	dc.w 0,$f2
mp4l	dc.w 0
botcols	ds.w	64



	dc.w $f009,$fffe
	dc.w	$9c,$8010
  	dc.w	$ffff,$fffe 		; End copper

gfxlib: dc.b 	"graphics.library",0	; library name
 
 	even

gfxbse: dc.l 	0	

dummy	dc.l 0

sprite0	ds.l 2*70
sprite1	ds.l 2*70
sprite2 ds.l 2*70
sprite3 ds.l 2*70

logo	ds.b 15712-32
	dc.w 0,$fff,$eee,$ddd,$ccc,$bbb,$aaa,$999,$888,$777
	dc.w $666,$555,$444,$333,$222,$111


 	ds.b 1000
font 	ds.b	512
	incbin sources:xmas/font2 


piccy	incbin sources:xmas/mountains