; *************************************
; **                                 **
; **  FLOATING POINT ROM: D800-DFFF  **
; **                                 **
; *************************************

		.org	$D800
		.segment "D800DFFF"
	
		.include "atari.inc"

		.export	AFP,FASC,IFP,FPI,ZFR0,ZF1
		.export	FSUB,FADD,FMUL,FDIV
		.export	PLYEVL,FLD0R,FLD0P,FLD1R,FLD1P,FSTOR,FSTOP,FMOVE
		.export	EXP,EXP10,LOG,LOG10
		.export	DA48,DA51,DBA1,DBAF,DC00,DE95,DF6C,DFAE,DFEA

; ******************************************
; **  ASCII -> Floating Point conversion  **
; ******************************************

AFP:		jsr	DBA1	; lees spaties aan begin van buffer weg.
		jsr	DBBB	; bekijk getal tot 1e cijfer
		bcs	@5	; begint NIET met '.+-', '+.', '-.', cijfer
		ldx	#$ED	; clear EEXP,NSIGN,ESIGN,FCHRFLG
		ldy	#4
		jsr	DA48
		ldx	#$FF
		stx	DIGRT
		jsr	ZFR0	; clear FR0
		beq	@2
@1:		lda	#$FF
		sta	FCHRFLG
@2:		jsr	DB94	; check first digit
		bcs	@6	; not a digit
		pha
		ldx	FR0+1
		bne	@3
		jsr	DBEB
		pla
		ora	FR0+5
		sta	FR0+5
		ldx	DIGRT
		bmi	@1
		inx
		stx	DIGRT
		bne	@1
@3:		pla
		ldx	DIGRT
		bpl	@4
		inc	EEXP
@4:		jmp	@1
@5:		rts

@6:		cmp	#'.'
		beq	@8
		cmp	#'E'
		beq	@9
		ldx	FCHRFLG
		bne	@16
		cmp	#'+'
		beq	@1
		cmp	#'-'
		beq	@7	; ehhhhh!?
@7:		sta	NSIGN
		beq	@1
@8:		ldx	DIGRT
		bpl	@16
		inx
		stx	DIGRT
		beq	@1
@9:		lda	CIX
		sta	FRX
		jsr	DB94
		bcs	@13
@10:		tax
		lda	EEXP
		pha
		stx	EEXP
		jsr	DB94
		bcs	@11
		pha
		lda	EEXP
		asl	A
		sta	EEXP
		asl	A
		asl	A
		adc	EEXP
		sta	EEXP
		pla
		clc
		adc	EEXP
		sta	EEXP
		ldy	CIX
		jsr	DB9D
@11:		lda	ESIGN
		beq	@12
		lda	EEXP
		eor	#$FF
		clc
		adc	#1
		sta	EEXP
@12:		pla
		clc
		adc	EEXP
		sta	EEXP
		bne	@16
@13:		cmp	#'+'
		beq	@14
		cmp	#'-'
		bne	@15
		sta	ESIGN
@14:		jsr	DB94
		bcc	@10
@15:		lda	FRX
		sta	CIX
@16:		dec	CIX
		lda	EEXP
		ldx	DIGRT
		bmi	@17
		beq	@17
		sec
		sbc	DIGRT
@17:		pha
		rol	A
		pla
		ror	A
		sta	EEXP
		bcc	@18
		jsr	DBEB
@18:		lda	EEXP
		clc
		adc	#'D'
		sta	FR0
		jsr	DC00
		bcs	@20
		ldx	NSIGN
		beq	@19
		lda	FR0
		ora	#%10000000
		sta	FR0
@19:		clc
@20:		rts

; ****************************************
; ** Floating Point -> ASCII conversion **
; ****************************************

FASC:		jsr	DA51
		lda	#'0'
		sta	$057F
		lda	FR0
		beq	@2
		and	#%01111111
		cmp	#$3F
		bcc	@3
		cmp	#$45
		bcs	@3
		sec
		sbc	#$3F
		jsr	DC70
		jsr	DCA4
		ora	#$80
		sta	LBUFF,X
		lda	LBUFF
		cmp	#$2E
		beq	@1
		jmp	@10
@1:		jsr	DCC1
		jmp	@11
@2:		lda	#$B0
		sta	LBUFF
		rts

@3:		lda	#1
		jsr	DC70
		jsr	DCA4
		inx
		stx	CIX
		lda	FR0
		asl	A
		sec
		sbc	#$80
		ldx	LBUFF
		cpx	#'0'
		beq	@5
		ldx	$0581
		ldy	$0582
		stx	$0582
		sty	$0581
		ldx	CIX
		cpx	#2
		bne	@4
		inc	CIX
@4:		clc
		adc	#1
@5:		sta	$ED
		lda	#'E'
		ldy	CIX
		jsr	DC9F
		sty	CIX
		lda	$ED
		bpl	@6
		lda	#0
		sec
		sbc	$ED
		sta	$ED
		lda	#$2D
		bne	@7
@6:		lda	#$2B
@7:		jsr	DC9F
		ldx	#0
		lda	$ED
@8:		sec
		sbc	#10
		bcc	@9
		inx
		bne	@8
@9:		clc
		adc	#10
		pha
		txa
		jsr	DC9D
		pla
		ora	#$80
		jsr	DC9D
@10:		lda	LBUFF
		cmp	#'0'
		bne	@11
		clc
		lda	INBUFF
		adc	#1
		sta	INBUFF
		lda	INBUFF+1
		adc	#0
		sta	INBUFF+1
@11:		lda	FR0
		bpl	@12
		jsr	DCC1
		ldy	#0
		lda	#$2D
		sta	(INBUFF),Y
@12:		rts

; ******************************************
; ** Integer -> Floating Point conversion **
; ******************************************

IFP:		lda	FR0
		sta	$F8
		lda	FR0+1
		sta	$F7
		jsr	ZFR0	;  clear ZFR0
		sed
		ldy	#$10
@1:		asl	$F8
		rol	$F7
		ldx	#3
@2:		lda	FR0,X
		adc	FR0,X
		sta	FR0,X
		dex
		bne	@2
		dey
		bne	@1
		cld
		lda	#$42
		sta	FR0
		jmp	DC00

; ******************************************
; ** Floating Point -> Integer conversion **
; ******************************************

FPI:		lda	#0
		sta	$F7
		sta	$F8
		lda	FR0
		bmi	@4
		cmp	#$43
		bcs	@4
		sec
		sbc	#$40
		bcc	@2
		adc	#0
		asl	A
		sta	$F5
@1:		jsr	DA5A
		bcs	@4
		lda	$F7
		sta	$F9
		lda	$F8
		sta	$FA
		jsr	DA5A
		bcs	@4
		jsr	DA5A
		bcs	@4
		clc
		lda	$F8
		adc	$FA
		sta	$F8
		lda	$F7
		adc	$F9
		sta	$F7
		bcs	@4
		jsr	DCB9
		clc
		adc	$F8
		sta	$F8
		lda	$F7
		adc	#0
		bcs	@4
		sta	$F7
		dec	$F5
		bne	@1
@2:		jsr	DCB9
		cmp	#5
		bcc	@3
		clc
		lda	$F8
		adc	#1
		sta	$F8
		lda	$F7
		adc	#0
		sta	$F7
@3:		lda	$F8
		sta	FR0
		lda	$F7
		sta	FR0+1
		clc
		rts
@4:		sec
		rts

ZFR0:		ldx	#FR0	; clear FR0
ZF1:		ldy	#6
DA48:		lda	#0
@1:		sta	0,X
		inx
		dey
		bne	@1
		rts

DA51:		lda	#5
		sta	INBUFF+1
		lda	#$80
		sta	INBUFF
		rts

DA5A:		clc
		rol	$F8
		rol	$F7
		rts

FSUB:		lda	FR1
		eor	#$80
		sta	FR1

FADD:		lda	FR1
		and	#%01111111
		sta	$F7
		lda	FR0
		and	#%01111111
		sec
		sbc	$F7
		bpl	@2

		ldx	#5
@1:		lda	FR0,X
		ldy	FR1,X
		sta	FR1,X
		tya
		sta	FR0,X
		dex
		bpl	@1

		bmi	FADD
@2:		beq	@3
		cmp	#5
		bcs	@5
		jsr	DC3E
@3:		sed
		lda	FR0
		eor	FR1
		bmi	@7
		ldx	#4
		clc
@4:		lda	FR0+1,X
		adc	FR1+1,X
		sta	FR0+1,X
		dex
		bpl	@4
		cld
		bcs	@6	; BCC DC00
@5:		jmp	DC00
@6:		lda	#1
		jsr	DC3A
		lda	#1
		sta	FR0+1
		jmp	DC00
@7:		ldx	#4
		sec
@8:		lda	FR0+1,X
		sbc	FR1+1,X
		sta	FR0+1,X
		dex
		bpl	@8
		bcc	@9
		cld
		jmp	DC00
@9:		lda	FR0
		eor	#$80
		sta	FR0
		sec
		ldx	#4
@10:		lda	#0
		sbc	FR0+1,X
		sta	FR0+1,X
		dex
		bpl	@10
		cld
		jmp	DC00

FMUL:		lda	FR0
		beq	DB24	; CLC/RTS
		lda	FR1
		beq	DB21
		jsr	DCCF
		sec
		sbc	#$40
		sec
		adc	FR1
		bmi	DB26	; SEC/RTS
		jsr	DCE0
@1:		lda	$DF
		and	#15
		sta	$F6
@2:		dec	$F6
		bmi	@3
		jsr	DD01
		jmp	@2
@3:		lda	$DF
		lsr	A
		lsr	A
		lsr	A
		lsr	A
		sta	$F6
@4:		dec	$F6
		bmi	@5
		jsr	DD05
		jmp	@4
@5:		jsr	DC62
		dec	$F5
		bne	@1

DB1A:		lda	$ED
		sta	FR0
		jmp	DC04
DB21:		jsr	ZFR0	;  clear ZFR0

DB24:		clc
		rts

DB26:		sec
		rts

FDIV:		lda	FR1
		beq	DB26	; SEC/RTS
		lda	FR0
		beq	DB24	; CLC/RTS
		jsr	DCCF
		sec
		sbc	FR1
		clc
		adc	#$40
		bmi	DB26	; SEC/RTS
		jsr	DCE0
		inc	$F5
		jmp	@3
@1:		ldx	#0

@2:		lda	FR0+1,X
		sta	FR0,X
		inx
		cpx	#12
		bne	@2

@3:		ldy	#5
		sec
		sed
@4:		lda	FRE,Y
		sbc	FR2,Y
		sta	FRE,Y
		dey
		bpl	@4
		cld
		bcc	@5
		inc	$D9
		bne	@3
@5:		jsr	DD0F
		asl	$D9
		asl	$D9
		asl	$D9
		asl	$D9

@6:		ldy	#5
		sec
		sed
@7:		lda	FRE,Y
		sbc	FR1,Y
		sta	FRE,Y
		dey
		bpl	@7
		cld
		bcc	@8
		inc	$D9
		bne	@6
@8:		jsr	DD09
		dec	$F5
		bne	@1
		jsr	DC62
		jmp	DB1A

DB94:		jsr	DBAF	; load A with 0.@9 OR first char of INBUFF
		ldy	CIX
		bcc	DB9D
		lda	(INBUFF),Y
DB9D:		iny		; wijs naar volgende character
		sty	CIX
		rts

DBA1:		ldy	CIX	; lees spaties aan begin van buffer weg.
		lda	#' '
@1:		cmp	(INBUFF),Y
		bne	@2
		iny
		bne	@1
@2:		sty	CIX
		rts

DBAF:		ldy	CIX	; load A with 0.@9 from INBUFF; SEC if failed.
		lda	(INBUFF),Y
		sec
		sbc	#'0'
		bcc	DBD0	; SEC/RTS
		cmp	#10
		rts

DBBB:		lda	CIX	; check digits up to 1st '0123456789'
		pha
		jsr	DB94	; laad eerste karakter; check '0123456789.+-'
		bcc	isdigit	; 't is een cijfer!
		cmp	#'.'
		beq	ispoint	; 't is een PUNT
		cmp	#'+'
		beq	issign	; 't is een PLUS
		cmp	#'-'
		beq	issign	; 't is een MIN
err:		pla

DBD0:		sec	; signaleer ERROR
		rts

issign:		jsr	DB94	; buffer starts with PLUS of MIN: next char
		bcc	isdigit	; cijfer? --> @4
		cmp	#'.'
		bne	err
ispoint:	jsr	DB94
		bcc	isdigit
		bcs	err
isdigit:	pla
		sta	CIX
		clc
		rts

DBE7:		ldx	#$E7
		bne	xe7
DBEB:		ldx	#$D5
xe7:		ldy	#4
@2:		clc
		rol	4,X
		rol	3,X
		rol	2,X
		rol	1,X
		rol	0,X
		rol	FRX
		dey
		bne	@2
		rts

DC00:		ldx	#0
		stx	FRE
DC04:		ldx	#4
		lda	FR0
		beq	@5
@1:		lda	FR0+1
		bne	@3
		ldy	#0
@2:		lda	FR0+2,Y
		sta	FR0+1,Y
		iny
		cpy	#5
		bcc	@2
		dec	FR0
		dex
		bne	@1
		lda	FR0+1
		bne	@3
		sta	FR0
		clc
		rts

@3:		lda	FR0
		and	#$7F
		cmp	#$71
		bcc	@4
		rts

@4:		cmp	#15
		bcs	@5
		jsr	ZFR0	;  clear ZFR0
@5:		clc
		rts

DC3A:		ldx	#FR0
		bne	xfr0
DC3E:		ldx	#FR1
xfr0:		stx	$F9
		sta	$F7
		sta	$F8
@1:		ldy	#4
@2:		lda	4,X
		sta	5,X
		dex
		dey
		bne	@2
		lda	#0
		sta	5,X
		ldx	$F9
		dec	$F7
		bne	@1
		lda	0,X
		clc
		adc	$F8
		sta	0,X
		rts

DC62:		ldx	#10
@1:		lda	FR0,X
		sta	FR0+1,X
		dex
		bpl	@1
		lda	#0
		sta	FR0
		rts

DC70:		sta	$F7
		ldx	#0
		ldy	#0
@1:		jsr	@2
		sec
		sbc	#1
		sta	$F7
		lda	FR0+1,X
		lsr	A
		lsr	A
		lsr	A
		lsr	A
		jsr	DC9D
		lda	FR0+1,X
		and	#%00001111
		jsr	DC9D
		inx
		cpx	#5
		bcc	@1
@2:		lda	$F7
		bne	@3
		lda	#$2E
		jsr	DC9F
@3:		rts

DC9D:		ora	#'0'
DC9F:		sta	LBUFF,Y
		iny
		rts

DCA4:		ldx	#10
@1:		lda	LBUFF,X
		cmp	#$2E
		beq	@2
		cmp	#'0'
		bne	@3
		dex
		bne	@1
@2:		dex
		lda	LBUFF,X
@3:		rts

DCB9:		jsr	DBEB
		lda	FRX
		and	#%00001111
		rts

DCC1:		sec
		lda	INBUFF
		sbc	#1
		sta	INBUFF
		lda	INBUFF+1
		sbc	#0
		sta	INBUFF+1
		rts

DCCF:		lda	FR0
		eor	FR1
		and	#%10000000
		sta	$EE
		asl	FR1
		lsr	FR1
		lda	FR0
		and	#%01111111
		rts

DCE0:		ora	$EE
		sta	$ED
		lda	#0
		sta	FR0
		sta	FR1
		jsr	DD28
		jsr	DBE7
		lda	FRX
		and	#%00001111
		sta	FR2
		lda	#5
		sta	$F5
		jsr	DD34
		jsr	ZFR0	;  clear ZFR0
		rts

DD01:		ldx	#$D9
		bne	xd9_1
DD05:		ldx	#$D9
		bne	xd8_2
DD09:		ldx	#$DF
xd9_1:		ldy	#$E5
		bne	xydfe5
DD0F:		ldx	#$DF
xd8_2:		ldy	#$EB
xydfe5:		lda	#5
		sta	$F7
		clc
		sed
@4:		lda	0,X
		adc	0,Y
		sta	0,X
		dex
		dey
		dec	$F7
		bpl	@4
		cld
		rts

DD28:		ldy	#5	; copy FR1 --> FR2
@1:		lda	FR1,Y
		sta	FR2,Y
		dey
		bpl	@1
		rts

DD34:		ldy	#5	; copy FR0 --> FRE
@1:		lda	FR0,Y
		sta	FRE,Y
		dey
		bpl	@1
		rts

PLYEVL:		stx	$FE
		sty	$FF
		sta	$EF
		ldx	#FR1
		ldy	#5
		jsr	FSTOR
		jsr	FMOVE
		ldx	$FE
		ldy	$FF
		jsr	FLD0R
		dec	$EF
		beq	DD88
@1:		jsr	FMUL
		bcs	DD88
		clc
		lda	$FE
		adc	#6
		sta	$FE
		bcc	@2
		lda	$FF
		adc	#0
		sta	$FF
@2:		ldx	$FE
		ldy	$FF
		jsr	FLD1R
		jsr	FADD
		bcs	DD88
		dec	$EF
		beq	DD88
		ldx	#FR1
		ldy	#5
		jsr	FLD1R
		bmi	@1
DD88:		rts

FLD0R:		stx	$FC
		sty	$FD
FLD0P:		ldy	#5
@1:		lda	($FC),Y
		sta	FR0,Y
		dey
		bpl	@1
		rts

FLD1R:		stx	$FC
		sty	$FD
FLD1P:		ldy	#5
@1:		lda	($FC),Y
		sta	$E0,Y
		dey
		bpl	@1
		rts

FSTOR:		stx	$FC
		sty	$FD
FSTOP:		ldy	#5
@1:		lda	FR0,Y
		sta	($FC),Y
		dey
		bpl	@1
		rts

; ### FMOVE: FR1 := FR0 ###

FMOVE:		ldx	#5
@1:		lda	FR0,X
		sta	FR1,X
		dex
		bpl	@1
		rts

EXP:		ldx	#<DE89		; calculate 10^(1/ln(10)*x) == e^x
		ldy	#>DE89
		jsr	FLD1R
		jsr	FMUL
		bcs	err2		; signal error (SEC/RTS)

EXP10:		lda	#0
		sta	$F1
		lda	FR0
		sta	$F0
		and	#%01111111
		sta	FR0
		sec
		sbc	#$40
		bmi	@1
		cmp	#4
		bpl	err2
		ldx	#FR2
		ldy	#5
		jsr	FSTOR
		jsr	FPI
		lda	FR0
		sta	$F1
		lda	FR0+1
		bne	err2
		jsr	IFP
		jsr	FMOVE
		ldx	#FR2
		ldy	#5
		jsr	FLD0R
		jsr	FSUB
@1:		lda	#10
		ldx	#<DE4D
		ldy	#>DE4D
		jsr	PLYEVL
		jsr	FMOVE
		jsr	FMUL
		lda	$F1
		beq	@4
		clc
		ror	A
		sta	FR1
		lda	#1
		bcc	@2
		lda	#$10
@2:		sta	$E1
		ldx	#4
		lda	#0
@3:		sta	$E2,X
		dex
		bpl	@3
		lda	FR1
		clc
		adc	#$40
		bcs	err2
		bmi	err2
		sta	FR1
		jsr	FMUL
@4:		lda	$F0
		bpl	@5
		jsr	FMOVE
		ldx	#<DE8F
		ldy	#>DE8F
		jsr	FLD0R
		jsr	FDIV
@5:		rts

err2:		sec	; signal EXP / EXP10 error
		rts

; ### EXP10 ###

DE4D:		.BYTE	$3D,$17,$94,$19,$00,$00	;  0.00001794190000
		.BYTE	$3D,$57,$33,$05,$00,$00	;  0.00005733050000
		.BYTE	$3E,$05,$54,$76,$62,$00	;  0.000554766200
		.BYTE	$3E,$32,$19,$62,$27,$00	;  0.003219622700
		.BYTE	$3F,$01,$68,$60,$30,$36	;  0.0168603036
		.BYTE	$3F,$07,$32,$03,$27,$41	;  0.0732032741
		.BYTE	$3F,$25,$43,$34,$56,$75	;  0.2543345675
		.BYTE	$3F,$66,$27,$37,$30,$50	;  0.6627373050
		.BYTE	$40,$01,$15,$12,$92,$55	;  1.15129255
		.BYTE	$3F,$99,$99,$99,$99,$99	;  0.9999999999

DE89:		.BYTE	$3F,$43,$42,$94,$48,$19	;  0.4342944819 [ 1/ln(10) ]
DE8F:		.BYTE	$40,$01,$00,$00,$00,$00	;  1.00000000   [ 1        ]

DE95:		stx	$FE
		sty	$FF
		ldx	#FR1
		ldy	#5
		jsr	FSTOR
		ldx	$FE
		ldy	$FF
		jsr	FLD1R
		jsr	FADD
		ldx	#FR2
		ldy	#5
		jsr	FSTOR
		ldx	#FR1
		ldy	#5
		jsr	FLD0R
		ldx	$FE
		ldy	$FF
		jsr	FLD1R
		jsr	FSUB
		ldx	#FR2
		ldy	#5
		jsr	FLD1R
		jsr	FDIV
		rts

LOG:		lda	#1
		bne	log_e

LOG10:		lda	#0


log_e:		sta	$F0	; A=0: base-10; A=1: base-e
		lda	FR0
		beq	@1	; error if FR0 <= 0
		bmi	@1
		jmp	DFF6	; LDA FR0 / STA FR1 / SEC / JMP DEE0


@1:		sec		; signal logarithm error!
		rts

DEE0:		sbc	#$40
		asl	A
		sta	$F1
		lda	FR0+1
		and	#$F0
		bne	@1
		lda	#1
		bne	@2
@1:		inc	$F1
		lda	#$10
@2:		sta	$E1
		ldx	#4
		lda	#0
@3:		sta	$E2,X
		dex
		bpl	@3

		jsr	FDIV
		ldx	#<DF66
		ldy	#>DF66
		jsr	DE95
		ldx	#FR2
		ldy	#5
		jsr	FSTOR
		jsr	FMOVE
		jsr	FMUL
		lda	#10
		ldx	#<DF72
		ldy	#>DF72
		jsr	PLYEVL
		ldx	#FR2
		ldy	#5
		jsr	FLD1R
		jsr	FMUL
		ldx	#<DF6C
		ldy	#>DF6C
		jsr	FLD1R
		jsr	FADD
		jsr	FMOVE
		lda	#0
		sta	FR0+1
		lda	$F1
		sta	FR0
		bpl	@4
		eor	#$FF
		clc
		adc	#1
		sta	FR0
@4:		jsr	IFP
		bit	$F1
		bpl	@5
		lda	#%10000000
		ora	FR0
		sta	FR0
@5:		jsr	FADD
		lda	$F0
		beq	@6
		ldx	#<DE89
		ldy	#>DE89
		jsr	FLD1R
		jsr	FDIV
@6:		clc
		rts

DF66:		.BYTE	$40,$03,$16,$22,$77,$66	;  3.16227766
DF6C:		.BYTE	$3F,$50,$00,$00,$00,$00	;  0.5000000000

DF72:		.BYTE	$3F,$49,$15,$57,$11,$08	;  0.4915571108
		.BYTE	$BF,$51,$70,$49,$47,$08	; -0.5170494708
		.BYTE	$3F,$39,$20,$57,$61,$95	;  0.3920576195
		.BYTE	$BF,$04,$39,$63,$03,$55	; -0.0439630355
		.BYTE	$3F,$10,$09,$30,$12,$64	;  0.1009301264
		.BYTE	$3F,$09,$39,$08,$04,$60	;  0.0939080460
		.BYTE	$3F,$12,$42,$58,$47,$42	;  0.1242584742
		.BYTE	$3F,$17,$37,$12,$06,$08	;  0.1737120608
		.BYTE	$3F,$28,$95,$29,$71,$17	;  0.2895297117
		.BYTE	$3F,$86,$85,$88,$96,$44	;  0.8685889644

; ARCTAN TABLE:

DFAE:		.BYTE	$3E,$16,$05,$44,$49,$00	;  0.001605444900
		.BYTE	$BE,$95,$68,$38,$45,$00	; -0.009568384500
		.BYTE	$3F,$02,$68,$79,$94,$16	;  0.0268799416
		.BYTE	$BF,$04,$92,$78,$90,$80	; -0.0492789080
		.BYTE	$3F,$07,$03,$15,$20,$00	;  0.0703152000
		.BYTE	$BF,$08,$92,$29,$12,$44	; -0.0892291244
		.BYTE	$3F,$11,$08,$40,$09,$11	;  0.1108400911
		.BYTE	$BF,$14,$28,$31,$56,$04	; -0.1428315604
		.BYTE	$3F,$19,$99,$98,$77,$44	;  0.1999987744
		.BYTE	$BF,$33,$33,$33,$31,$13	; -0.3333333113
DFEA:		.BYTE	$3F,$99,$99,$99,$99,$99	;  0.9999999999

		.BYTE	$3F,$78,$53,$98,$16,$34	;  0.7853981634 [ arctan(1) ]

DFF6:		lda	FR0
		sta	FR1
		sec
		jmp	DEE0

		.BYTE	0,0

		.END