anchor.diff:  
     procedure editor.arrowup;
     begin
  +    li.strnode(self.position.value).str := led.value;
       if self.position.move_prev then
       begin
         if self.position.index - self.topline.index < 5 then
  
positive.code:     y := 1;
      w := crt.windMaxX;
      h := crt.windMaxY;
      //pause( 'windmaxy = ' + n2s( h ));
      topline := self.buf.make_cursor;
      position := self.buf.make_cursor;
    end;
  
negative.code:   procedure editor.arrowdown;
      var screenline : word;
    begin
      li.strnode(self.position.value).str := led.value;
      if self.position.move_next then
        begin
          assert( self.topline.index <= self.position.index );
  