TERMINAL DEVICE

PROBLEM TO BE SOLVED: To provide a terminal device capable of automatically changing the OS of portable information equipment or the like according to the capacity of a RAM installed therein. SOLUTION: The terminal device has a means for calculating the capacity of the RAM installed in the device, a means for selecting the OS actuated according to the calculation, and a means for loading the selected OS into the RAM and actuating it. Thus, of a plurality of OSs stored, the most suitable OS can be automatically selected and actuated according to the capacity of the RAM installed in the device; for example, in the case of a RAM with a small capacity, an OS of small size with reduced functions is actuated to enable to handle large data even with a small memory capacity; in the case of a RAM with a large capacity, the normal OS with unreduced functions is actuated whereby more advanced OS functions can be provided.