Patent ID: 7980955

Claim:
A data processing apparatus in which at least two removable storage media each store both a respective program and associated data, the apparatus comprising: a removable storage medium reader; and means for executing the program from a first one of the removable storage media which is currently readable by the reader, using data stored on the first removable storage medium, the executing means and/or the program being arranged so that at at least a predetermined point within execution of the program, the first removable storage medium may be removed from the reader and a second, different, one of the removable storage media associated with the reader, so that execution of the program can continue using data read from the second removable storage medium, in which: the programs stored on the removable storage media are such that any of the removable storage media can act as the first one of the removable storage media; the data stored on a removable storage medium has associated description data stored on that removable storage medium; and one of the removable storage media stores description data relating to data stored on the other removable storage medium and one or more data part identifiers identifying respective parts of the data stored on that removable storage medium that can be processed in accordance with a corresponding version of the program; the apparatus comprising: means operable to determine, from one or more data part identifiers stored on a removable storage medium associated with the reader, a part of the data stored on that removable storage medium that can be processed in accordance with the version of the program being executed by the apparatus; a memory for storing user data relating to data stored on a removable storage medium; means for detecting user access of the user data relating to data not stored on a removable storage medium currently associated with the reader; and means, responsive to such a detection, for generating a message to prompt the user to associate another removable storage medium with the reader.