Entering here will 'clear' only the calculator stack.

16C5	SET-STK	LD	HL,(STKBOT)	Fetch STKBOT.
		LD	(STKEND),HL	This clears the stack.

In all cases make MEM address the calculator's memory area.

		PUSH	HL	Save STKEND.
		LD	HL,+5C92	The base of the memory area.
		LD	(MEM),HL	Set MEM to this address.
		POP	HL	Restore STKEND to the HL
		RET		register pair before returning.

THE 'RECLAIM THE EDIT-LINE' SUBROUTINE'

16D4	REC-EDIT	LD	DE,(E-LINE)	Fetch E-LINE.
		JP	19E5,RECLAIM-1	Reclaim the memory.

THE 'INDEXER' SUBROUTNE
This subroutine is used on several occasions to look through tables.  The entry point is at INDEXER.

16DB	INDEXER-1	INC	HL	Move on to consider the next
				pair of entries.
16DC	INDEXER	LD	A,(HL)	Fetch the first of a pair of
		AND	A	entries but return if it is
		RET	Z	zero - the end marker.
		CP	C	Compare it to the supplied
				code.
		INC	HL	Point to the second entry.
		JR	NZ,16DB,INDEXER-1	Jump back if the correct entry
				has not been found.
		SCF		The carry flag is set upon a
		RET		successful search.

THE 'CLOSE #' COMMAND ROUTINE
This command allows the user to CLOSE streams.  However for streams +00 to +03 the 'initial' stream data is restored and these streams cannot therefore be CLOSEd.

16E5	CLOSE	CALL	171E,STR-DATA	The existing data for the stream
				is fetched.
		CALL	1701,CLOSE-2	Check the code in that
				stream's channel.
		LD	BC,+0000	Prepare to make the stream's
				data zero.
		LD	DE,+A3E2	Prepare to identify the use of
		EX	DE,HL	streams +00 to +03.
		ADD	HL,DE	The carry flag will be set with
				streams +04 to +0F.
		JR	C,16FC,CLOSE-1	Jump forward with these
		LD	BC,+15D4	streams; otherwise find the
		ADD	HL,BC	correct entry in the 'initial
				stream data' table.
		LD	C,(HL)	Fetch the initial data
		INC	HL	for streams +00 to +03.
		LD	B,(HL)
16FC	CLOSE-1	EX	DE,HL	Now enter the data; either
		LD	(HL),C	zero & zero, or the initial
		INC	HL	values.
		LD	(HL),B
		RET

THE 'CLOSE-2' SUBROUTINE
The code of the channel associated with the stream being closed has to be 'K', 'S', or 'P'.

1701	CLOSE-2	PUSH	HL	Save the address of the
				stream's data.