04246638 is referenced by 80 patents and cites 6 patents.

A method for controlling usage of a programmable computing machine which operates in accordance with uncoded or published machine language operation codes including uniquely encoding the uncoded operation codes of instructions of a program to be used on the computing machine as a function of location of the instructions in memory and as a function of machine state, and adding to the machine a decoder that decodes only the uniquely encoded operation codes. Apparatus for controlling usage of a programmable computing machine which operates in response to uncoded or published machine language operation codes including memories which store machine user created programs and operating system programs, in which each program has instructions with uncoded and encoded operation codes, decoders to decode the encoded operation codes of the instructions of the user created program and the encoded operation codes of the instructions of the operating system program, and a circuit to execute the instructions of the user created program and the operating system program having the decoded and the uncoded operation codes.

Title
Method and apparatus for controlling usage of a programmable computing machine
Application Number
5/942422
Publication Number
4246638
Application Date
September 14, 1978
Publication Date
January 20, 1981
Inventor
William J Thomas
6146 Winterbrook Dr., San Jose, 95129
CA, US
Agent
Phillips Moore Weissenberger Lempio & Majestic
IPC
H04K 1/00
G06F 13/00
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