Key lock system for personal computer
US5506990A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1993 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Mar 22, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for controlling the operation of computer power and reset switches. A separate key switch enables a user to selectively disable the power and reset switches of the computer. The user has the option of operating the computer in a secured mode, in which a user key is required to actuate the power and reset switches, or alternatively in an unsecured mode in which the power and reset switches operate normally. Control circuitry is connected to the switches and operates in the unsecured mode for enabling power supply and reset circuitry operating state transitions responsive to the user actuation of the respective switches. In the secured mode, the circuitry disables the power supply state transitions that normally would occur responsive to user actuation of the first switch, and disables the reset circuitry state transitions, but only from the inactive operating state to the active operating state, so the reset circuitry is prevented from remaining in a continuous reset loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.