Pac-Man was designed to have no ending – as long as the player keeps at least one life, he or she should be able to play the game indefinitely. However, a bug keeps this from happening: Normally, no more than seven fruit are displayed at the bottom of the screen at any given time. But when the internal level counter, which is stored in a single byte (8 bits), reaches 255, the subroutine that draws the fruit erroneously “rolls over” this number to zero, causing it to try to draw 256 fruit instead of the usual seven.