In this way, in accordance with the device control program, the control unit 11 can control both the printer function and scanner function of a device 2. However, since some of the devices 2 possess only one of the printer function and scanner function, it is desirable to register the devices 2 for each function.
Next, an example will be described for the user interface of the device control program according to the first embodiment when only one device for executing a printer function and one device for executing a scanner function can be registered on the data processing apparatus 1. When a device 2 has been registered on the data processing apparatus 1 for the printer function, the device control program controls this device when executing the printer function. Similarly, when a device 2 has been registered on the data processing apparatus 1 for the scanner function, the device control program controls this device when executing the scanner function.