section	TheCode,code

		bsr.w	TakeSystem

		lea	Bmap,a4
		moveq	#0,d4
		move.l	#-$8000000*2,a1
		move.l	#100,a2
		move.l	#8000,a3
					;$1333333 each x
					;$28f5c2 each y
		move.l	#$199999,d1
		move.l	#$28f5c2,d2
		move.l	#319,d5
		moveq	#$f,d6
		moveq	#7,d7

yloop:		move.l	d5,d3
		move.l	#$8000000*2,a0
	
xloop:		move.l	a2,d0

		movem.l	d1-d7/a2-a6,-(a7)
		move.w	d0,d3
		moveq	#0,d4		; q1 = 0
		moveq	#0,d5		; q2 = 0
		moveq	#0,d6		; x  = 0
		moveq	#0,d7		; y  = 0
		subq.w	#1,d3

mandelloop2:	move.l	d6,d1		; D1 = oldx;
		move.l	d4,d6
		sub.l	d5,d6
		add.l	a0,d6		; x(D6) = q1(D4) - q2(D5) + acoo(A0);
		move.l	d1,d2
		bpl.b	Pos1
		neg.l	d1
Pos1:		eor.l	d7,d2
		tst.l	d7
		bpl.b	Pos2
		neg.l	d7
Pos2:		move.l	d1,d0
		swap	d0
		move.w	d0,d2
		mulu	d7,d0
		clr.w	d0
		swap	d0
		swap	d7
		mulu	d7,d1
		clr.w	d1
		swap	d1
		mulu	d2,d7
		add.l	d0,d7
		add.l	d1,d7
		tst.l	d2
		bpl.b	Pos3
		neg.l	d7
Pos3:		moveq	#6,d0
		asl.l	d0,d7
		add.l	a1,d7	; y(D7) = 2 * oldx(D1) * y(D7) + bcoo(A1);
		moveq	#5,d0
		move.l	d7,d5
		bpl.b	Pos4
		neg.l	d5
Pos4:		move.l	d5,d2
		swap	d5
		mulu	d5,d2
		clr.w	d2
		swap	d2
		mulu	d5,d5
		add.l	d2,d5
		add.l	d2,d5
		asl.l	d0,d5		; q2(D4) = y(D7)^2;
		bvs.b	mandelexit
		move.l	d6,d4
		bpl.b	Pos5
		neg.l	d4
Pos5:		move.l	d4,d2
		swap	d4
		mulu	d4,d2
		clr.w	d2
		swap	d2
		mulu	d4,d4
		add.l	d2,d4
		add.l	d2,d4
		asl.l	d0,d4		; q1(D4) = x(D6)^2;
		bvs.b	mandelexit
		move.l	d4,d0
		add.l	d5,d0
		bvs.b	mandelexit
		cmpi.l	#536870912,d0	;$8000000 * 4
		bgt.b	mandelexit
		dbf	d3,mandelloop2

		moveq	#1,d3
mandelexit:	subq.w	#1,d3
		move.l	d3,d0
		movem.l	(a7)+,d1-d7/a2-a6

		tst.w	d0
		beq.b	nextx

		movem.l	d2-d4/a4,-(sp)	
		move.l	d3,d2
		lsr.w	#3,d3
		add.w	d3,d4
		and.w	d7,d2
		eor.b	d6,d2
		add.l	d4,a4

		lsr.w	d0
		bcc.b	nobp0
		bset.b	d2,(a4)
nobp0:		add.w	a3,a4
		lsr.w	d0
		bcc.b	nobp1
		bset.b	d2,(a4)
nobp1:		add.w	a3,a4
		lsr.w	d0
		bcc.b	nobp2
		bset.b	d2,(a4)
nobp2:		add.w	a3,a4
		lsr.w	d0
		bcc.b	nobp3
		bset.b	d2,(a4)
nobp3:		add.w	a3,a4
		lsr.w	d0
		bcc.b	nobp4
		bset.b	d2,(a4)
nobp4:
pix_err:	movem.l	(sp)+,d2-d4/a4

nextx:		sub.l	d1,a0
		btst	#6,$bfe001
		beq.b	Mousewait
		dbra	d3,xloop

nexty:		add.l	d2,a1
		add.w	#40,d4
		cmpi.w	#(200*40),d4
		blt.w	yloop
	
MouseWait:	btst	#6,$bfe001
		bne.b	MouseWait

		bsr.b	RestoreSystem
		rts				; Done!

***********************************************************

TakeSystem:	movea.l	4,a6			; ExecBase
		jsr	-$84(a6)		; Forbid() multitasking

		lea	$dff000,a5		; Custom chip base
		bsr.b	InstallBmap
		bsr.w	InstallSprites
		bsr.w	InstallCopper
		rts				; Done

***********************************************************

RestoreSystem:	lea	$dff000,a5

		movea.l	4,a6			; ExecBase
		lea	GraphicsName,a1		; "graphics.library"
		moveq.l	#0,d0			; Any version
		jsr	-$228(a6)		; OpenLibrary()
		move.l	d0,a1			; Copy ptr to GfxBase
		move.l	$26(a1),$80(a5)		; Install old system copperlist
		jsr	-$19e(a6)		; CloseLibrary()
		move.w 	DMACONSave,$96(a5)	; Activate old DMA channels
		jsr	-$8a(a6)		; Permit() multitasking
		rts				; Done

***********************************************************

InstallBmap:	lea	bmapptrs,a0
		move.l	#Bmap,d0		; say our bmap address is $12345678
		move.w	d0,6(a0)		;   write $5678 to $e2 reg in copperlist
		swap	d0
		move.w	d0,2(a0)		;   write $1234 to $e0
		swap	d0
	
		add.l	#8000,d0
		move.w	d0,14(a0)
		swap	d0
		move.w	d0,10(a0)
		swap	d0
	
		add.l	#8000,d0
		move.w	d0,22(a0)
		swap	d0
		move.w	d0,18(a0)
		swap	d0
	
		add.l	#8000,d0
		move.w	d0,30(a0)
		swap	d0
		move.w	d0,26(a0)
		swap	d0
	
		add.l	#8000,d0
		move.w	d0,38(a0)
		swap	d0
		move.w	d0,34(a0)

		rts

***********************************************************

InstallCopper:	move.l	#Copper,$80(a5)		; install copper
		rts

*********************************************************** 

InstallSprites:	lea	sprptrs,a0
		move.l	#NullSprite,d0	  
		move.w	d0,6(a0)	
		move.w	d0,14(a0)
		move.w	d0,22(a0)
		move.w	d0,30(a0)
		move.w	d0,38(a0)
		move.w	d0,46(a0)
		move.w	d0,54(a0)
		move.w	d0,62(a0)
		swap	d0  
		move.w	d0,2(a0)	
		move.w	d0,10(a0)
		move.w	d0,18(a0)
		move.w	d0,26(a0)
		move.w	d0,34(a0)
		move.w	d0,42(a0)
		move.w	d0,50(a0)
		move.w	d0,58(a0)
		rts

***********************************************************

		section	squid,data_c

GraphicsName:	dc.b	'graphics.library',0
		EVEN

Copper:
	dc.w	$1fc,0
	dc.w	$106,$c40
	dc.w	$0100,$5200		 ; bit plane control reg.0
	dc.w	$0102,$0000		 ; scroll value
	dc.w	$0104,$0000		 ; blp/sprite priority reg.
	dc.w	$0108,$0000		 ; odd bitplane modulo value
	dc.w	$010a,$0000		 ; even bitplane modulo value
	dc.w	$0180,$0000
	dc.w	$0182,$0100
	dc.w	$0184,$0200
	dc.w	$0186,$0300
	dc.w	$0188,$0400
	dc.w	$018a,$0500
	dc.w	$018c,$0600
	dc.w	$018e,$0700
	dc.w	$0190,$0800
	dc.w	$0192,$0900
	dc.w	$0194,$0a00
	dc.w	$0196,$0b00
	dc.w	$0198,$0c00
	dc.w	$019a,$0d00
	dc.w	$019c,$0e00
	dc.w	$019e,$0f00
	dc.w	$01a0,$0fb0
	dc.w	$01a2,$0001
	dc.w	$01a4,$0002
	dc.w	$01a6,$0003
	dc.w	$01a8,$0004
	dc.w	$01aa,$0005
	dc.w	$01ac,$0006
	dc.w	$01ae,$0007
	dc.w	$01b0,$0008
	dc.w	$01b2,$0009
	dc.w	$01b4,$000a
	dc.w	$01b6,$000b
	dc.w	$01b8,$000c
	dc.w	$01ba,$000d
	dc.w	$01bc,$000e
	dc.w	$01be,$000f

	dc.w	$008e,$2c81		 ; upper left corner of disp. window
	dc.w	$0090,$f4c1		 ; lower right corner of disp. window
	dc.w	$0092,$0038		 ; start of bpl. (horizontal)
	dc.w	$0094,$00d0		 ; endo of bpl. (horizontal)
bmapptrs:
	dc.w	$00e0,$0000		 ; adr of bplane 1 (long - 2 words)
	dc.w	$00e2,$0000		 ; low word of bplane 1 adr
	dc.w	$00e4,$0000
	dc.w	$00e6,$0000
	dc.w	$00e8,$0000
	dc.w	$00ea,$0000
	dc.w	$00ec,$0000
	dc.w	$00ee,$0000
	dc.w	$00f0,$0000
	dc.w	$00f2,$0000
sprptrs:
	dc.w	$0120,$0000
	dc.w	$0122,$0000
	dc.w	$0124,$0000
	dc.w	$0126,$0000
	dc.w	$0128,$0000
	dc.w	$012a,$0000
	dc.w	$012c,$0000
	dc.w	$012e,$0000
	dc.w	$0130,$0000
	dc.w	$0132,$0000
	dc.w	$0134,$0000
	dc.w	$0136,$0000
	dc.w	$0138,$0000
	dc.w	$013a,$0000
	dc.w	$013c,$0000
	dc.w	$013e,$0000

	dc.w	$ffff,$fffe

Bmap:	dcb.b	8000*5,0

***********************************************************

	section farb,bss_c

NullSprite:	ds.l	3	; 2 control words/2 data words/2 blank words
DMACONSave:	ds.w	1
INTENASave:	ds.w	1
Level3Save:	ds.l	1