THE 'PRINT A FLASHING CHARACTER' SUBROUTINE
The 'error cursor' and the 'mode cursors' are printed using this subroutine.

18C1	OUT-FLASH	EXX		Save the current register.
		LD	HL,(ATTR-T)	Save the ATTR-T & MASK-T on
		PUSH	HL	the machine stack.
		RES	7,H	Ensure that FLASH is
		SET	7,L	active.
		LD	(ATTR-T),HL	Use these modified values
				for ATTR-T & MASK-T.
		LD	HL,+5C91	This is P-FLAG.
		LD	D,(HL)	Save P-FLAG also on the
		PUSH	DE	machine stack.
		LD	(HL),+00	Ensure INVERSE 0, OVER 0,
				and not PAPER 9 nor INK 9.
		CALL	09F4,PRINT-OUT	The character is printed.
		POP	HL	The former value of P-FLAG
		LD	(P-FLAG),H	is restored.
		POP	HL	The former values of ATTR-T
		LD	(ATTR-T),HL	& MASK-T are also restored
		EXX		before returning.
		RET

THE 'PRINT THE CURSOR' SUBROUTINE
A return is made if it is not the correct place to print the cursor but if it is then either 'C', 'E', 'G', 'K' or 'L' will be printed.

18E1	OUT-CURS	LD	HL,(K-CUR)	Fetch the address of the
		AND	A	cursor but return if the
		SBC	HL,DE	correct place is not being
		RET	NZ	considered.
		LD	A,(MODE)	The current value of MODE is
		RLC	A	fetched and doubled.
		JR	Z,18F3,OUT-C-1	Jump forward unless delaing with
				Extended mode or Graphics.
		ADD	A,+43	Add the appropriate offset to
				give 'E' or 'G'.
		JR	1909,OUT-C-2	Jump forward to print it.
18F3	OUT-C-1	LD	HL,+5C3B	This is FLAGS.
		RES	3,(HL)	Signal 'K-mode'.
		LD	A,+4B	The character 'K'.
		BIT	2,(HL)	Jump forward to print 'K'.
		JR	Z,1909,OUT-C-2	If 'the printing is to be in
				K-mode'.
		SET	3,(HL)	The 'printing is to be in L-mode'
				so signal 'L-MODE'.
		INC	A	Form the character 'L'.
		BIT	3,(FLAGS2)	Jump forward if not in
		JR	Z,1909,OUT-C-2	'C-mode'.
		LD	A,+43	The character 'C'.
1909	OUT-C-2	PUSH	DE	Save the DE register pair
		CALL	18C1,OUT-FLASH	whilst the cursor is printed
		POP	DE	- FLASHing.
		RET		Return once it has been done.

Note: It is the action of considering which cursor-letter is to be printed that determines the mode - 'K' vs 'L/C'.

THE 'LN-FETCH' SUBROUTINE
This subroutine is entered with the HL register pair addressing a system variable - S-TOP or E-PPC.
The subroutine returns with the system variable holding the line number of the following line.

190F	LN-FETCH	LD	E,(HL)	The line number held by the
		INC	HL	system variable is collected.