The ‘DX’ in ‘DX-Ball’ is a reference to DirectX—a set of application programming interfaces from Microsoft to handle multimedia related operations. The original DX-Ball is a 100% DirectX game, meaning it only relies on DirectX components to run.
If the ball ever gets stuck in a loop between unbreakable bricks, the game will detect the situation after a short while and zap all persistent bricks on the board. This event can also be triggered by firing repeatedly at unbreakable bricks with the laser guns.