; LCKCV.MAC -- CHECK BIT VALUE
; AUTHOR:  LEN
; DATE WRITTEN:  23-JAN-78
;
	.NLIST	TOC		;TBL OF CONTENTS NOT WANTED
;
	.TITLE	LCKCV
	.SBTTL	CHECK BIT VALUE
;
	.ENABL	AMA		;NO PC-REL ADDRS
;
;	FUNCTION LCKCV (IBIT, IVEC)
;		IBIT	= BIT TO CHECK (STARTS AT 0)
;		IVEC	= BIT STRING
;
;	RETURNS 1 IF SET, 0 IF NOT
;
LCKCV::
	MOV	#LCKCVN,R0	;NAME TO TRACE BK
	MOV	(R0)+,R4
	MOV	(R0)+,-(SP)	;PUSH (R0)+ ONTO STACK
	JSR	R4,NAM$
;
	CLR	R0		;CLEAR FOR DIVIDE
	MOV	@2(R5),R1	;GET BIT TO CHECK
	DIV	#16.,R0		;OFFSETS IN R0,R1
	ASL	R0		;BY 2 FOR BYTE ADDR
	ADD	4(R5),R0	;ADDRESS OF IVEC+ OFFSET
	MOV	#1,R2		;BIT 0
	ASH	R1,R2		;TURN ON APPROPRIATE BIT TO CHECK
	BIT	(R0),R2		;CHECK BIT
	BNE	ON		;IF SET
	CLR	R0		;RETURN 0 IF NOT
	BR	RETURN		
ON:	MOV	#1,R0		;BIT IS ON
RETURN:	RTS	PC		;RETURN TO CALLER
;
LCKCVN:	.RAD50	/LCKCV /	;TRACE NAME
;
	.END