From Pong-Story.com:  Although the pinball systems didn't play true PONG games, Sears also released two system playing PONG variants and car racing games: Speedway and Speedway IV (designed by Atari). The games could be played by one, two or four players, the number of players being set by a switch and the number of extra pads connected to the system. The switch toggled the HUMAN and ROBOT modes. The former was for two or four players (two using the hard-wired controllers, four using the extra two controllers that could be plugged to the unit). The latter was a single-player mode agains the machine. A third system called Speedway was also made by Sears. This was a cheaper version of VIDEO ACTION IV, also known as INDY 500 and sold by Universal Research in 1976. Obviously, one could modify this version of Speedway to play the fourth game. All these systems used a dedicated chip (F4301) made by Universal Research Labs in 1976, and packaged by Omnetics Inc.