An electronic device that supports multiple command systems embodies a function for switching from one to another of the multiple command systems regardless of the specifications of the command system being used. A hybrid device 10 that operates based on commands sent from a host computer 200 sets a specific transition condition for changing to another command system after the last command system change corresponding to a switching command sent from the host computer 200. When the set transition condition is met, the computer returns to the command system used before the command system was last changed or changes to another command system.