anchor.diff:  
   ;;; helper functions
   
  -(defparameter *incudine-start-timestamp* nil
  +(defvar *incudine-start-timestamp* nil
     "The local-time timestamp when Incudine was started.")
   
  -(defparameter *incudine-start-samples* 0
  +(defvar *incudine-start-samples* 0
     "The result of `incudine:now' when `*incudine-start-timestamp*' was generated.")
   
   (defun timestamp-to-incudine (timestamp)
     "Convert a local-time timestamp to an Incudine sample number."
  -  (unless *incudine-start-timestamp*
  -    (if (eql (incudine:rt-status) :started)
  -        (setf *incudine-start-timestamp* (local-time:now)
  -              *incudine-start-samples* (incudine:now))
  -        (error "cl-patterns cannot generate a timestamp for Incudine as Incudine is not running. Try (start-backend :incudine) if you want to use Incudine, or disable its backend.")))
     (* (local-time:timestamp-difference timestamp *incudine-start-timestamp*)
        (incudine:rt-sample-rate)))
   
  
positive.code:                  (find-if (lambda (x)
                              (position x (list 'buffer 'bufnum) :test #'string-equal))
                            dsp-controls)
                   buffer ;; get the actual buffer number
                   :dur 16
                   :quant 0
                   :latency 0))))
  
negative.code:     (warn "cl-patterns' *CLOCK* is nil; starting the clock on your behalf with START-CLOCK-LOOP: ~s."
            (start-clock-loop)))
    (incudine:rt-start)
    (setf *incudine-start-timestamp* (local-time:now)
          *incudine-start-samples* (incudine:now)))
  
  (defmethod stop-backend ((backend (eql :incudine)))
    (incudine:rt-stop))
  