05671281 is referenced by 29 patents and cites 12 patents.

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. The functional characteristic definition is loaded from nonvolitile memory into a nonscannable register within a secure portion of a control logic circuit each time power is applied to the data processing system and the definition is then utilized to enable only selected functional characteristics. Alternate functional characteristics may thereafter be selectively enabled by entering a security code which matches one of a number of preloaded codes and an encoded alternate functional characteristic definition. The alternate functional characteristic definition may be enabled on a one-time, metered, or regularly scheduled basis and variable capability data processing systems may be implemented in this manner utilizing a single manufactured system, without the necessity of manufacturing and storing multiple data processing system models.

Title
Self modifying access code for altering capabilities
Application Number
29856
Publication Number
5671281
Application Date
August 10, 1994
Publication Date
September 23, 1997
Inventor
Paul Leonard Wiltgen
Hurley
NY, US
Steven Frank Hajek
West Hurley
NY, US
Michael James Chan
Raleigh
NC, US
John Edward Campbell
Hurley
NY, US
Agent
Whitham Curtis Whitham & McGinn
Agent
Lynn L Augspurger
Assignee
International Business Machines Corporation
NY, US
IPC
H04L 9/00
H04L 9/32
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