Near the end of the NES's lifespan, upon the release of the AV Famicom and the top-loading NES 2, the design of the game controllers was modified slightly. Though the original button layout was retained, the redesigned device abandoned the brick shell in favor of a dog bone shape. In addition, the AV Famicom joined its international counterpart and dropped the hardwired controllers in favor of detachable controller ports. However, the controllers included with the Famicom AV had cables which were 90 cm (3 feet) long, as opposed to the standard 180 cm(6 feet) of NES controllers.
 the unoriginal design of the controller was what shape?