JR	358C,END-TESTS	the final tests.
3559	STRINGS	RRCA		The string comparisons now
				have the range 02-03 with carry
				set for 'equal' and 'not equal'.
		PUSH	AF	Save the offset.
		CALL	2BF1,STK-FETCH	The lengths and starting
		PUSH	DE	addresses of the strings are
		PUSH	BC	fetched from the claculator
		CALL	2BF1,STK-FETCH	stack.
		POP	HL	The length of the second string.
3564	BYTE-COMP	LD	A,H	
		OR	L	
		EX	(SP),HL	
		LD	A,B	
		JR	NZ,3575,SEC-PLUS	Jump unless the second string
		OR	C	is null.
356B	SECND-LOW	POP	BC	Here the second string is either
				null or less than the first.
		JR	Z,3572,BOTH-NULL	
		POP	AF	
		CCF		The carry is complemented to
		JR	3588,STR-TEST	give the correct test results.
3572	BOTH-NULL	POP	AF	Here the carry is used as it
		JR	3588,STR-TEST	stands.
3575	SEC-PLUS	OR	C	
		JR	Z,3585,FRST-LESS	The first string is now null,
				the second not.
		LD	A,(DE)	Neither string is null, so their
		SUB	(HL)	next bytes are compared.
		JR	C,3585,FRST-LESS	The first byte is less.
		JR	NZ,356B,SECND-LOW	The second byte is less.
		DEC	BC	The bytes are equal; so the
		INC	DE	lengths are decremented and a
		INC	HL	jump is made to BYTE-COMP
		EX	(SP),HL	to compare the next bytes of
		DEC	HL	the reduced strings.
		JR	3564,BYTE-COMP	
3585	FRST-LESS	POP	BC	
		POP	AF	
		AND	A	The carry is cleared here for the
				correct test results.
3588	STR-TEST	PUSH	AF	For the string tests, a zero is
		RST	0028,FP-CALC	put on to the calculator stack.
		DEFB	+A0,stk-zero	
		DEFB	+38,end-calc	
358C	END-TESTS	POP	AF	These three tests, called as
		PUSH	AF	needed, give the correct results
		CALL	C,3501,NOT	for all twelve comparisons. The
		POP	AF	initial carry is set for 'not equal'
		PUSH	AF	and 'equal', and the final carry
		CALL	NC,34F9,GREATER-0	is set for 'greater than', 'less
		POP	AF	than' and 'equal'.
		RRCA		
		CALL	NC,3501,NOT	
		RET		Finished.

THE 'STRING CONCATENATION' OPERATION
(Offset 17: 'strs-add')

This subroutine performs the binary operation 'A$+B$. The parameters for these strings are fetched and the total length found. Sufficient room to hold both the strings is made available in the work space and the strings are copied over. The result of this subroutine is therefore to produce a temporary variable A$+B$ that resides in the work space.