Blank ScreensYou will notice that when you are playing against the computer in 3-D Tic-Tac-Toe, the screen will go completely BLANK when the computer is thinking. The purpose for this is to free additional CPU time for thinking rather than using precious processing cycles to draw the screen 60 times per second. This technique can be seen in other Atari 2600 games as well. For instance, when playing the computer in Othello, the harder levels will often blank out the screen for a second or two in order to decrease the wait time for the human player.
In the case of 3D Tic-Tac-Toe, however, the complexity is so much greater that it is hard to keep track of who has gone where. Having the screen go blank, therefore, introduces the possibility of a programming glitch that I have heard theorized about on more than one occasion. Some say that the Atari 2600 3-D Tic-Tac-Toe computer opponent cheats!
I have not confirmed this for sure, but considering that the screen does conveniently blank out between moves, it is conceivable that changes are made that would go unnoticed by the human player! It may also explain why I rarely won when playing against computer. If this is the case, it is probably a programming bug, as it is very unlikely that a game programmer for a commercial company as large as Atari would blatantly introduce cheating on the part of the computer.
Development3-D Tic-Tac-Toe originated as a popular BASIC game. It was already included in David Ahl's influential book BASIC Computer Games in 1978, where it is stated that the game comes from Dartmouth College.
Additional information contributed by General Error.