Calculator program security system
Patent 4139893 Issued on February 13, 1979. Estimated Expiration Date: 
August 22, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 22, 1997. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References3859635 InventorAssigneeApplicationNo. 05/826789 filed on 08/22/1977US Classes:708/130, Programmable calculator360/1, RECORDING ON OR REPRODUCING FROM AN ELEMENT OF DIVERSE UTILITY708/135For securityExaminersPrimary: Smith, JerryAttorney, Agent or FirmInternational ClassesG06F 15/02 (20060101)G06F 21/00 (20060101) AbstractA calculator program is stored on a magnetic recording medium or in a memory such as a read-only-memory. The program is read into or coupled to a programmable calculator for controlling the programmable calculator. A calculator program security system is provided whereby a security code is stored along with the program. If the security code is set, then the program cannot be examined by an operator of the calculator but the program may still be used to control the calculator. If the security code is not set, the operator may examine the program by using the calculator's learn mode. By setting the security code when the program is first stored on the magnetic recording medium or in the aforementioned memory, a proprietary program may be protected from someone using the programmable calculator to obtain a copy of the proprietary program. | |
