In the late 1970s, I bought a chess computer at J. C. Penney, the one in a brown plastic case with the chessboard printed on top and a keypad to the right with

In the late 1970s, I bought a chess computer at J. C. Penney, the one in a brown plastic case with the chessboard printed on top and a keypad to the right with a red LED display. I returned it after about a week because it cheated. Whenever I moved to take its King/Queen, it would call an illegal move, and claim that its King/Queen was on the other side of the board. I've wondered what glitch in programming would create that behavior.