Video Chess

Video Chess is a chess game for the Atari VCS (renamed Atari 2600 in 1982) programmed by Larry Wagner and Bob Whitehead and released by Atari in 1979. Both programmers later developed games for Activision.

Gameplay
The game is played from an overhead perspective. The player uses a cursor to select and move pieces, rather than using chess notation. If an attempted move is illegal, the move is blocked with a warning sound. If the right-most switch is set to A, the computer plays as white; setting it to B lets the player play as white. With the left switch, selecting A allows the board to be set as the player pleases, whereas selecting B sets up the board for a regulation chess game. Eight different difficulty levels have the computer-player take a variable amount of time to determine its moves, ranging from a few seconds to ten hours.

Development
The box art of the first production run of the Atari Video Computer System features a chess piece, though Atari was not yet contemplating designing a chess game. A man from Florida supposedly sued Atari over the box art. Video Chess programmer Bob Whitehead said he was not aware of such a lawsuit.

At first, the console's strict hardware limitations seemed to preclude it hosting a chess program. The console's Television Interface Adaptor chip can only display three sprites in each scanline, or six (such as in Space Invaders) with the right programming. The eight-piece-wide chess board exceeds this limitation. Whitehead developed a technique he called Venetian blinds, in which a sprite's horizontal position is alternated between two values at every scanline, while the hardware outputs video signal. This results in one sprite being displayed as two objects, each composed of horizontal stripes. This technique allowed to display eight chess pieces in each row while using only four sprites.

Atari developed a bank switching ROM cartridge to allow Video Chess prototypes to exceed four kilobytes, the maximum without bank switching. The released version is 4KB at a time when most games were 2KB, and the bank switching technology from the prototype was later used for other Atari VCS games. It was one of six games labeled as "Special Edition" on the box, and some speculate that this designation on these games refers to a combination of the 4KB ROM size and other factors.

Reception
Video magazine praised it as "a reward for Atari owners" which even basic chess players "should find rewarding for many hours of enjoyment". The reviewers were surprised that the gameplay was limited to a single player, and noted the high retail price of US$40 1979, but they praised the programming which prevents illegal moves, and which includes more advanced chess concepts like castling and en passant capturing which had not yet become standard in all chess video games.