;
	.NLIST	TOC		;NO TABLE OF CONTENTS
	.TITLE  IRNSC
	.SBTTL	NUMBER OF SIGNIFICANT CHARACTERS
;
;*	FUNCTION IRNSC (IVEC, IS, NCH)
;
;	RETURNS NUMBER OF SIGNIFICANT CHARACTERS
;	WHERE
;		IVEC = INTEGER*2 VECTOR OF ASCII CHARS
;		IS   = START POSITION IN IVEC 
;		NCH  = NUMBER OF CHARS TO SEARCH
;
;	BACKSCANS IVEC STARTING WITH IVEC(IS+NCH-1) UNTIL FIRST
;	NON-BLANK CHARACTER IS FOUND
;		E.G.  IVEC = '13 CHARACTERS    '
;		      ICH  = IRNSC(IVEC,1,17)
;		      (ICH IS SET TO 13)
;
;
;
;-
BLANK:	.ASCII	/ /
	.EVEN
;
IRNSC::	MOV	(R5)+,R1	;NUMBER OF ARGS(UPDATE R5 PAST)
	MOV	(R5)+,R1	;ADDR OF IVEC
	ADD	@(R5)+,R1	;START CHAR IN IVEC
	DEC	R1		;+1 OFFSET
	MOV	@(R5)+,R0	;GET NCH
	ADD	R0,R1		;POSITION OF LAST CHAR TO BACKSCAN
;
;	BEGIN LOOP TO BACKSCAN TILL NON-BLANK CHAR FOUND
;
LOOP:	CMPB	-(R1),BLANK	;CHECK IF BLANK
	BNE	DONE
	SOB	R0,LOOP		;DECREMENT NCH, R0 RETURNS FUNCTION RESULT
;
DONE:	RTS	PC		;RETURN TO CALLER
	.END