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Password operated system for preventing unauthorized or accidental computer memory alteration

  • US 3,890,601 A
  • Filed: 03/11/1974
  • Issued: 06/17/1975
  • Est. Priority Date: 03/11/1974
  • Status: Expired due to Term
First Claim
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1. In a digital computer used to control the operation of a machine, said computer including, a high-speed operating system memory adapted to contain the computer system operating programs, a high-speed program memory adapted to contain at least one of a plurality of the programs used to operate said machine, input and output means for operating and observing the operation of said computer, a low-speed memory device having replaceable easily stored permanent memory elements, said low-speed memory device being capable of storing substantially more information than said high-speed memories thereby permitting storage of said plurality of programs along with the operating system programs and having a protected portion wherein stored information cannot be altered by said computer, said protected portion containing a password that is unique to each one of said memory elements, and means for transferring information between said high-speed memories and said low-speed memory;

  • an automatic lockout device comprising;

    means for comparing the password in said high-speed operating system memory and the password in said low-speed memory, and means to prevent alteration of information in said low-speed memory when the passwords in said high-speed operating system memory and said low-speed memory do not match.

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