Abstract: A system is disclosed for selectively altering the functional characteristics of a data processing system without physical or mechanical manipulation by providing an access code from a remote personal identification number generator to a secure controller and store of the computer system. This enables remote authorization of change in function of the computer system, such as performance tune up, speeding clock time, changing function and like changes. The computer system is first manufactured having a predetermined set of functional characteristics. A multibit alterable code which includes a functional characteristic definition is then initially loaded into physically secure, nonvolatile memory within the data processing system, utilizing an existing bus, or a fusible link which may be opened after loading is complete.