; version 1.0 Feb 4, 1988
; first version - no modifications
;
	.title	readable
	.entry	readable,0

	movzbl	#-1,r0	; assume it will work

	prober	#0,#4,@4(ap)

	bneq	10$
	clrl	r0	; clear it if it didn't work

10$:	ret

	.end