Digital image signal processing apparatus and controlling method used in the same

A controlling method used in a digital image signal processing apparatus selectively performing reading and writing of any digital image signal to a designated recording medium among a plurality of recording media, to each of which a digital image signal is writable, and displaying the digital image signal which is being at least one of read and written on a display, the method comprising:

• storing a plurality of identification information for identifying the respective information media on a nonvolatile memory;
• acquiring a registration file describing identification information items of the respective recording media in initial registration, if there occurs a request to execute writing or reading of a digital image signal, the request designating one of the recording media;
• comparing an identification information corresponding to the designated recording medium in the registration file with the corresponding identification information stored in the nonvolatile memory, and thereby detecting change in the identification information of the designated recording medium;
• and
• displaying on the display a message indicating failure in access to the recording medium, when the change in the identification information of the designated recording medium is detected.