The game is housed in a large custom rectangular cabinet that takes up 16 square feet. Each side of the cabinet has two steering wheels and four pedals. The monitor is set in to the top face of the cabinet and looked down upon. The game uses a 25 inch full color RGB display and does not use color overlays, representing the first full color video game.
The processing electronics consisted of a card cage that included a "Backplane" or "Motherboard", eight identical car function boards, and three unique, common processing boards that the backplane board supported and interconnected. Each of the eleven boards had its own, on board, fixed 5 volt regulator IC. All of the logic circuitry was TTL, and no microprocessors were used.
Each game was sold with two spare car boards and one each of the three processing boards, so that the game owner could ordinarily repair it by simple circuit board substitution. Two "card extender" boards were furnished with each game sold that enabled technicians to probe individual components on suspect boards while they were still operating in the game. A complete set of circuit board logic diagrams was also furnished, as was a set of schematics for the modified GE color monitor.
The cabinet also features overhead mirrors to allow spectators to watch the game while it's being played.
Gameplay is a simulation of a Indianapolis 500 style race, in which players compete by racing each other with simulated IndyCar race cars. The player car colors are purple, peach, yellow, green, light blue, white, red and dark blue.
- A clone of the game, bearing the same name, was released by Atari subsidiary Kee Games.
- Indy 800 was followed up the following year with a smaller 4 player version entitled Indy 4.