LED, Line Editor vers. 1.0 -- Paul Pomerleau -- August 6, 1987

  LED is a subset of the EASE editor.  It can be included 
in any non comercial program.

On entry:
  BC = length of buffer
  DE = buffer location
  A  = command bits
    0 (low bit) -- Zero = ignore BC and HL, use previous values
    1		-- One  = Set the insert
		   Zero = Leave it as user set it last edit
    2		-- One  = Insert On
		   Zero = Insert Off
    3		-- One  = Initailize position (start at first char)
		   Zero = Same position as last edit
			(Values for BC and DE must be the same as last edit)
    4		-- One  = Output the line
		   Zero = Use output of last edit (Bit 3 should be One)
On exit:
  BC = length of input
  A  = return code
	0 = Normal "Done"
	1 = Extension command #1
	2 = Extension command #2
	etc.

Data needed:
		A buffer pointed to by DE which is two 
	bytes longer than length required.  The first 
	location must be contain a zero.  Any string 
	terminated by a zero may follow.
	  Example:
	BUFFER:	  db	0,'Hello, World!',0

		A kill buffer of the name KILL (made 
	PUBLIC) and KILSIZ, a PUBLIC equate, which specifies 
	how long KILL is.  KILL must be one byte longer than 
	KILSIZ claims it to be and must contain a string 
	ending with a zero.
	  Example:
	kilsize	equ	1000
	KILL:	db	'Blech.',0
		ds	kilsiz + 1 - 7	; (Length) + (1) - (Length of 'Blech.')
		public	kilsiz, KILL

		A list of command keys and an equate stating 
	how long the list is.  Both made public.  Uppercase 
	characters representing control chars and the high 
	bit set representing a preceeding Meta key.
		After all standard LED functions are 
	acounted for, the program may include other keys 
	which will return control to the program with a 
	Extension Command Number in A.
	  Example:
	CMDLST:	db	'QDSEXAF','S'+80h,'D'+80h,'G','H',127,'T',
		db	127+80h,'R','Y'+80h,'YUVIPWMC'
		db	'N'+80h		; Extension Command #1
	cmdlen	equ	$ - CMDLST
		public	CMDLST, cmdlen


Example usage:

		public	CMDLST, cmdlen, KILL, kilsiz
		ext	LED

		org	100h

RE_EDIT:	xor	a
		ld	(KILL),a	; Make sure there's nothing to UNDO
		ld	bc,size
		ld	de,BUFFER+1
		ld	(de),a
		dec	de
		ld	(de),a		; Clear the buffer -- No initial text
		ld	a,00011111b	; Do output,
					; Start at first char,
					; Insert On,
					; Set insert,
					; Use BC, HL.
		call	LED
		or	a		; Was <^Q><^N> hit?
		jr	nz,RE_EDIT	; nz = Yes
		ld	a,c		; Get the length in A
		ret

BUFFER:		db	0,'Xyz inc.',0
		ds	50
size		equ	$ - BUFFER - 2
CMDLST:		db	'QDSEXAF','S'+80h,'D'+80h,'G','H',127,'T',
		db	127+80h,'R','Y'+80h,'YUVIPWMC'
cmdlen		equ	$ - CMDLST
kilsize		equ	1000
KILL:		db	'Blech.',0
		ds	KILSIZ + 1 - 7	; (Length) + (1) - (Length of 'Blech.')

  If you make any changes to LED (other than keystroke 
definitions), please tell me about the change.  I'm on 
Lillipute Z-NODE -- (312) 664-1730

                                              Paul Pomerleau