.TITLE	LENGTH		
; JEFFREY KODOSKY	ARL	NOV75
;
; SUBR
; ENTRY:	1 ARG		<S>
; EXIT:		1 ARG		<INT>
; ERRORS:	NONE
; CALLS:	I2ATM
; 0 IS RETURNED IF <S> IS ATOMIC.  FINAL CDR (NIL OR ATOM) NOT COUNTED.
	.GLOBL	LENGTH,ZLENGTH,QI2ATM
LENGTH:	CLR	R0
	MOV	(R5)+,R1
LEN1:	BIT	#2,(R1)+
	BNE	LEN2
	BIT	#3,@R1
	BNE	LEN2
	INC	R0
	MOV	@R1,R1
	BNE	LEN1
LEN2:	MOV	R0,-(SP)
	QI2ATM
	.WORD	0
ZLENGTH=.-LENGTH
	.END