http://www.megalextoria.com/wordpress/index.php/2017/03/15/atari-5200-commercial/
In the above Atari 5200 commercial you can see the original four port Atari 5200 as well as the trackball (advertised as coming soon).
Read more: http://www.megalextoria.com/wordpress/index.php/2017/03/15/atari-5200-commercial/