opt c+,d+
	
; ******** labels ********

custom=$dff000

bplcon0	= custom+$100
bpl1pth	= custom+$0e0
bpl2pth 	= custom+$0e4
bpl3pth	= custom+$0e8
bpl4pth	= custom+$0ec
bpl5pth	= custom+$0f0
diwstrt	= custom+$08e
diwstop	= custom+$090
ddfstrt	= custom+$092
ddfstop	= custom+$094
bpl1mod	= custom+$108
bpl2mod	= custom+$10a
dmacon	= custom+$096
dmbits	= %1000001100000000
bconbits	= %0101001000000000
colstart	= custom+$180


; ************************

	move #$0000,colinc
	move.w #bconbits,bplcon0
	move #$a000,bpl1pth
	move #$b000,bpl2pth
	move #$c000,bpl3pth
	move #$d000,bpl4pth
	move #$e000,bpl5pth
	move #$2c81,diwstrt
	move #$f4c1,diwstop
	move #$0038,ddfstrt
	move #$00d0,ddfstop
	move #$0000,bpl1mod
	move #$0000,bpl2mod

; set up bit planes

	move.w #2000,d0
	move.l #$a000,a1
	move.l #$b000,a2
	move.l #$c000,a3
	move.l #$d000,a4
	move.l #$e000,a5

fplloop:	

	move.l #$55555555,(a1)+
	move.l #$33333333,(a2)+
	move.l #$0f0f0f0f,(a3)+
	move.l #$00ff00ff,(a4)+
	move.l #$ffffffff,(a5)+
	subq.w #1,d0
	bne fplloop
	
; set up colour registers

	lea colstart,a0
coloop:	addq.b #2,colinc
	move colinc,(a0)+
	cmp $dff1be,a0
	bne coloop
	
	
; enable DMA

	move #dmbits,dmacon
	
loop:
	bra loop
	
	even

colinc:	dc.w $0000