THE 'E-LINE-NO' SUBROUTINE
This subroutine is used to read the line number of the line in the editing area.  If there is no line number, i.e. a direct BASIC line, then the line number is considered to be zero.
In all cases the line number is returned in the BC register pair.

19FB	E-LINE-NO	LD	HL,(E-LINE)	Pick up the pointer to the
				edit-line.
		DEC	HL	Set the CH-ADD to point to the
		LD	(CH-ADD),HL	location before any number.
		RST	0020,NEXT-CHAR	Pass the first code to the A
				register.
		LD	HL,+5C92	However before considering
		LD	(STKEND),HL	the code make the calculator's
				memory area a temporary
				calculator stack area.
		CALL	2D3B,INT-TO-FP	Now read the digits of the line
				number.  Return zero if no
				number exists.
		CALL	2DA2,FP-TO-BC	Compress the line number into
				the BC register pair.
		JR	C,1A15,E-L-1	Jump forward if the number
				exceeds '65,536'.
		LD	HL,+D8F0	Otherwise test it against
		ADD	HL,BC	'10,000'.
		JP	C,1C8A,REPORT-C	Give report C if over '9,999'.
		JP	16C5,SET-STK	Return via SET-STK that
				restores the calculator stack to
				its rightful place.

THE 'REPORT AND LINE NUMBER PRINTING' SUBROUTINE
The entry point OUT-NUM-1 will lead to the number in the BC register pair being printed.  Any value over '9,999' will not however be printed correctly.
The entry point OUT-NUM-2 will lead to the number indirectly addressed by the HL register pair being printed.  This time any necessary leading spaces will appear.  Again the limit of correctly printed numbers is '9,999'.

1A1B	OUT-NUM-1	PUSH	DE	Save the other registers
		PUSH	HL	throughout the subroutine.
		XOR	A	Clear the A register.
		BIT	7,B	Jump forward to print a zero
				rather than '-2' when
		JR	NZ,1A42,OUT-NUM-4	reporting on the edit-line.
		LD	H,B	Move the number to the
		LD	L,C	HL register pair.
		LD	E,+FF	Flag 'no leading spaces'.
		JR	1A30,OUT-NUM-3	Jump forward to print the
				number.
1A28	OUT-NUM-2	PUSH	DE	Save the DE register pair.
		LD	D,(HL)	Fetch the number into the
		INC	HL	DE register pair and save 
		LD	E,(HL)	the pointer (updated).
		PUSH	HL	
		EX	DE,HL	Move the number to the HL
		LD	E,+20	register pair and flag 'leading
				space are to be printed'.

Now the integer form of the number in the HL register pair is printed.

1A30	OUT-NUM-3	LD	BC,+FC18	This is '-1,000'.
		CALL	192A,OUT-SP-NO	Print a first digit.
		LD	BC,+FF9C	This is '-100'.
		CALL	192A,OUT-SP-NO	Print the second digit.
		LD	C,+F6	This is '-10'.
		CALL	192A,OUT-SP-NO	Print the third digit.