Methods and arrangements for limiting access to computer controlled functions and devices

Methods and arrangements are provided to verify if a requesting computer application is authorized to change a controlled parameter associated with a computer controlled device and/or function. To accomplish this, one or verification functions are employed to analyze a security code or absence thereof, as identified by a requesting application. If the security code, which may be encrypted, matches a known or calculated valid security code, then the requesting application is deemed to be authorized to change the controlled parameter and/or modify certain limitations associated with an acceptable range for the controlled parameter. If the security code does not match a known or calculated valid security code, then the requesting application is deemed to be unauthorized to change the controlled parameter outside of a previously established acceptable range for the controlled parameter. The verification function can be implemented in a ROM to increase the security and to thwart attempts to circumvent the authorization scheme. Several independent verification functions can be arranged to support the verification of a plurality of authorized applications.