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Computer with improved keyboard password functions

DC
  • US 4,942,606 A
  • Filed: 02/07/1989
  • Issued: 07/17/1990
  • Est. Priority Date: 02/07/1989
  • Status: Expired due to Term
First Claim
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1. A method of operating a computer system of the type having a CPU and memory associated therewith and a peripheral controller device coupled to said CPU, comprising the steps of:

  • (a) switching said peripheral controller device between(i) a normal operating mode wherein said peripheral controller device sends unsolicted information to said CPU and said CPU sends unsolicited information to said peripheral controller device without reference to password data, and(ii) a lock-out mode wherein said peripheral controller device cannot send information to said CPU unless password data previously stored in said memory associated with said CPU is first entered to cause a switch back to said normal operating mode, but said CPU can send information to said peripheral controller device;

    (b) monitoring unsolicited information transferred from said CPU to said peripheral controller device when said peripheral controller device is in said lock-out mode, and selectively allowing only pre-selected information transferred to said peripheral controller device by said CPU to activate said peripheral controller device for selected functions without switching from said lock-out mode.

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