anchor.diff:  
   ;;;; * TTY mode
   
  -(defmethod enter-tty-mode ((obj display) tty &optional (how ""))
  +(defmethod enter-tty-mode ((obj display) tty &optional (driver ""))
     (declare (integer tty))
  -  (declare (string how))
  -  (setf (slot-value obj 'tty) (foreign-funcall "brlapi__enterTtyMode" :pointer (display-handle obj) :int tty :string how brlapi-code)))
  +  (declare (string driver))
  +  (setf (slot-value obj 'tty) (foreign-funcall "brlapi__enterTtyMode" :pointer (display-handle obj) :int tty :string driver brlapi-code)))
   
   (defmethod leave-tty-mode ((obj display))
     (foreign-funcall "brlapi__leaveTtyMode" :pointer (display-handle obj) brlapi-code)
  
positive.code:       (0 nil)
        (1 (mem-ref key 'key-code)))))
  
  (defun expand-key (keycode)
    (with-foreign-objects ((command :int) (arg :int) (flags :int))
      (foreign-funcall "brlapi_expandKeyCode"
                       key-code keycode
                       :pointer command :pointer arg :pointer flags
                       :int)
      (values (intern (foreign-funcall "brlapi_getKeyName"
  
negative.code:   (auth :string)
    (host :string))
  
  (defun open-connection (&optional auth host)
    "Open a new connection to BRLTTY on HOST usng AUTH for authorization.
  Return a DISPLAY object which can further be used to interact with BRLTTY."
    (with-foreign-object (settings 'settings)
      (setf (foreign-slot-value settings 'settings 'auth)
            (if (stringp auth) auth (null-pointer))
            (foreign-slot-value settings 'settings 'host)
            (if (stringp host) host (null-pointer)))
      (let* ((handle (foreign-alloc :char :count (foreign-funcall "brlapi_getHandleSize" :int)))
  