XIN:	LXI	H,0		; ANSWER := 0;
XINLOOP:CALL	GET		; A :== INPUT [character];
	CPI	'0'		; is A LT '0'?
	RC			; if so then return;
	CPI	':'		; is A LT ':' [numerics]?
	JC	XINSHIFT	; if so then go shift it in;
	CPI	'A'		; is A LT 'A'?
	RC			; if so then return;
	CPI	'G'		; is A LT'G' [alphabetic A to F]?
	RNC			; if not then return;
	ADI	9		; A := A + 9 [convert to hexadecimal];
XINSHIFT:ANI	15		; A := A & b'00001111' [mask low order];
	DAD	H		; shift ANSWER register pair
	RC			;     left four bit
	DAD	H		;     positions using
	RC			;     double byte addition
	DAD	H		;     and test each
	RC			;     operation for
	DAD	H		;     an overflow error
	RC			;     return condition;
	ORA	L		; A := A OR L [add new code to lower order];
	MOV	L,A		; restore low order to ANSWER;
	JMP	XINLOOP		; reiterate for next nybble;