A gaming machine is provided with a cabinet, at least one user-interface button, a value-receiving mechanism associated with the cabinet, a display unit associated with the cabinet, a processor disposed in the cabinet, system software representing a game that may be played by a player, encoded data generated from at least one message digest that was generated based on using an encoding function with the system software, loading software stored in memory that loads system software into random-access memory and verifies correctness and authenticity of the system software, and operating system (OS) software stored in memory that comprises an application programming interface including an application programming interface portion that provides a software interface to the display unit.