Create FACtoB.s

FP-converter/FACtoB.s

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+* @com.wudsn.ide.asm.hardware=APPLE2
+************************************
+* 	FP1 TO FAC TO BASIC            *
+*          CALL 32768,X            *
+*	         PRINT X		             *
+************************************
+		org $8000
+		
+CHKCOM		equ $DEBE
+PTRGET		equ $DFE3
+MOVMF		equ $EB2B
+MOVFM		equ $EAF9
+
+** Woz FP Accumulator 4 Byte + 1 Byte Extra + 1 Byte SIGN **
+FP1		equ $FA	;Translate F8 --> FA
+E		equ $FE ;Translate FC --> FE
+SIGN		equ $EB ;Translate F3 --> EB
+
+MEM		equ $8080
+*
+		** FP1 to MEM to FAC conversion FAC 5 Bytes **
+*
+ENTRY		lda FP1		; X1 1 Byte --> 9D FAC
+		inc A		; 2^(FP1+1)
+		sta MEM
+		
+		lda FP1+1	; M1 Hi 2 Byte --> 9E FAC
+		asl
+		eor #$80	; Not Hi Bit Mantissa (change Sign)
+		sta MEM+1
+		
+		lda FP1+2	; M1 3 Byte --> 9F FAC
+		sta MEM+2
+		
+		lda FP1+3	; M1 Lo 4 Byte --> A0 FAC
+		sta MEM+3
+		
+		lda E		; Extra 00 5 Byte --> A1 FAC
+		sta MEM+4
+		
+*		lda $EB		; SIGN (F3 to EB) 6 Byte --> A2 FAC
+*		sta MEM+5
+		***************************
+* 
+		ldy #$80 	;Hi Byte MEM
+		lda #$80 	;Lo Byte MEM
+		jsr MOVFM	;MEM->FAC (9D to A2)
+*
+		jsr CHKCOM
+		jsr PTRGET
+		tax
+		jsr MOVMF	;FAC->VARIABLE
+DONE		rts