;			LEN.MAC
;
;  J=LEN(STRING)
;  J=LENGTH(STRING), WHERE J+1 IS THE POSITION OF THE FIRST NULL
;  BYTE IN THE STRING
;
	.TITLE	LEN
LEN::	CLR	R0
	MOV	2(R5),R1
1$:	TSTB	(R1)+
	BEQ	2$
	INC	R0
	BR	1$
2$:	RTS	PC
	.END