Apple II STY Init MANT1 LDY, Sty, Calling Sequence, High-Order, Integer Byte, Low-Order, STY M1

M1+2 prior to calling FLOAT.

FLOAT takes approximately 3 msec. lonqer to convert zero to floating point form than other arguments. The user may check for zero prior to calling FLOAT and increase throughput.

*

*LOW-ORDER INT. BYTE IN A-REG

*HIGH-ORDER BYTE IN Y-REG

			*
85	FA		XFLOAT	STA	M1+1
84	F9			STY	M1	INIT MANT1
A0	00			LDY	#$0
84	FB			STY	M1+2
05	D9			ORA	M1	CHK BOTH
						BYTES FOR
D0	03			BNE	TOFLOAT ZERO
85	F8			STA	X1	IF SO CLR X1
60				RTS		AND RETURN
4C	51	F4	TOFLOAT	JMP	FLOAT	ELSE FLOAT
						INTEGER
Example: Float +274 ($0112 hex)
			CALLING SEQUENCE
A0	01			LDY #$01		HIGH-ORDER
						INTEGER BYTE
A9	12			LDA #$12		LOW-ORDER
						INTEGER BYTE
84	F9			STY M1
85	FA			STA M1+1
A9	00			LDA #$00
85	F8			STA M1+2
20	51	F4		JSR FLOAT

Upon returning from FLOAT, FP1 contains the floating point representation of +274.

	_____		_____		_____		_____
FP1	$88		$44		$80		0 (+274)
_____		_____		_____		_____
	X1		M1

FIX subroutine (address $F640)

Purpose: To extract the integer portion of a floating point number with truncation (ENTIER function).

Entry: A floating point value is in FP1. It need not be normalized.

Uses: RTAR.