anchor.diff:       :with res := nil
        :do
        (let ((first-byte (aref cluster (* i 32))))
  -       (unless  (or (zerop first-byte)
  -                    (= #xE5 first-byte))
  +       (unless (or (zerop first-byte)
  +                   (= #xE5 first-byte))
            (if (= #x0F (aref cluster (+ 11 (* i 32))))
                (push (make-long-dir
                       :order (aref cluster (* i 32))
  
positive.code: 
  (defmethod sys.gray:stream-read-sequence ((stream fat32-file-stream) sequence &optional (start 0) end)
    (assert (member (direction stream) '(:input :io)))
    (error "Feature not implemented"))
  
  (defmethod sys.gray:stream-write-char ((stream fat32-file-character-stream) char)
    (error "Feature not implemented"))
  
  (defmethod sys.gray:stream-read-sequence ((stream fat32-file-character-stream) sequence &optional (start 0) end)
    (assert (member (direction stream) '(:input :io)))
    (error "Feature not implemented"))
  
  (defmethod sys.gray:stream-read-char ((stream fat32-file-character-stream))
    (assert (member (direction stream) '(:input :io)))
  
negative.code:   'character)
  
  (defmethod sys.gray:stream-write-byte ((stream fat32-file-stream) byte)
    (error "Feature not implemented: ~a" 'sys.gray:stream-write-byte))
  
  (defmethod sys.gray:stream-read-byte ((stream fat32-file-stream))
    (assert (member (direction stream) '(:input :io)))
  