CLM beginner's problem with definstrument

[Lawrence Troxler]

This is directly from the tutorial, but doesn't work on my Linux/ACL4.3
system. Is there something I need to configure?

USER(17): (definstrument simp (start-time duration frequency amplitude) 
  (multiple-value-bind (beg end) (get-beg-end start-time duration)
    (let ((s (make-oscil :frequency frequency)))                      
      (run                                                                     
       (loop for i from beg to end do                                 
         (outa i (* amplitude (oscil s))))))))                                 


Error: NIL cannot be converted to a pathname.
  [condition type: TYPE-ERROR]
[1] USER(18): 

--  Larry Troxler  --  lt@westnet.com  --  Patterson, NY USA  --