Computer Chess

Computer Chess
Company: Atari
Model #:
Bob Whitehead and Larry Wagner
Year: 1978
The only known prototype that has a production end label.


Computer Chess is a bit of an oddity among prototypes.  Once thought to simply be an early name for Video Chess, it turns out that Computer Chess is actually a slightly different and earlier version of the game.  While there arenít a ton of differences (Chess is Chess), there are still enough to take notice.


The first (and most obvious) difference is that the coordinates for the chess board is displayed at the bottom of screen.  When a piece is selected, a picture of the piece and the coordinates of the move (in Chess notation of course) are displayed on screen.  This was probably removed from the final version (Video Chess) because most players aren't familiar with Chess notation and would be confused by all the numbers and letters all over the screen. 


Another major difference in Computer Chess is that there are no pawn promotions, the feature simply isnít in the game yet.   If a pawn reaches the other side of the board it will simply be stuck there, unable to move.  Since Computer Chess also lacks the Ďsetup modeí found in Video Chess  the player canít manually promote their pawns either.  The lack of pawn promotions really breaks some major strategies, making the game a bit tougher (although the computer canít do it either so it evens out a bit).



Some other minor differences in Computer Chess are that it's played using the right joystick.  I can't offer any explanation for this except that it might be a programming bug.  Computer Chess also displays the difficulty level in the bottom left corner as C# (# being the difficulty level), Video Chess simply displays a large number at the top of the screen.  Computer Chess also makes some psychedelic sounds to go along with the flashing colors is shows when its thinking.  These were wisely taken out of Video Chess.

Interestingly, Computer Chess has a minor (but amusing) bug in it that was fixed in the final version.  If the player and computer follow a certain series of moves it is possible for the player to take control of the computerís pawn.  One way to see this bug is to follow the following steps (special thanks to Nukey Shay for discovering this):
  1. Most of the time, the AI (playing white) will begin by moving it's kings pawn forward 2 spaces.
  2. Threaten this position by moving your queens pawn two
  3. The AI will defend its pawn position by moving its queens knight
  4. If you then move your kings bishop pawn to threaten the pawn from the opposite side, it responds by taking this one
  5. The victorious pawn is now yours!

Did you ever notice how the chess pieces are made up of lines?  This is because of a special trick created by Bob Whitehead to display more than six sprites per line (which wouldn't have been enough for Chess).  This trick called "Venetian Blinds" allowed the 2600 to display up to eight sprites per row (instead of the normal six) by alternating them between two sets of scanlines (four on one set of scanlines, and four on the other).  It was the development of this trick that made a chess program on the 2600 possible.



For many years there was a rumor that Atari was being sued for lack of a Chess cartridge.   The story goes that Atari had never planned to do a chess program as everyone thought that Chess was well beyond the capabilities of the poor old 2600.  However someone forgot to tell marketing this, and they stuck a big ol' Chess piece on the system box (this part is true, as the first version of the 2600 system box does indeed have a chess knight on it).   Then the rumor states that a man in Florida had bought the 2600 assuming that it would have a Chess program available and after realizing that Atari planned no such thing, he sued for false advertising.  So Atari could either cough up a Chess cartridge or pay out a lot of money in lawsuits.  While this is a nice story (and somewhat plausible given the whole Intellivision Keyboard module lawsuit), programmer Bob Whitehead states that he was unaware of any such lawsuit. 


So after much research it has been concluded that Computer Chess is really an early version of the program that eventually become Video Chess.  Interestingly Computer Chess was the first 2600 game to break the 4K barrier, originally weighing in at a hefty 6K!  Rather than go through the expense of releasing Computer Chess as a bankwitched cart, Atari decided to strip it down so it could fit into a regular 4K cart.  Unfortunately it appears that the chess notation was one of the features that had to be axed to make room for pawn promotions, setup mode, and other bug fixes.  Computer Chess is an interesting glimpse into the WIP changes that were made in the early days of 2600 programming.


Version Cart Text Description
7/7/78 Ches 7-7-78 EPROM board only
?????? Computer Chess Prototype cart has a production end label.


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