Character and signal generator for detecting keyboard disconnected condition generated by an interrupted booting process and generating signal indicating that keyboard is now coupled thereto
US5222228A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1990 |
| Grant date | Jun 22, 1993 |
| Priority date | — |
| Expiry date | Dec 14, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/023
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A signal generator for generating an F1 keyboard keystroke and a clock signal responsive to expiration of a time delay sufficient for a computer to which the generator is coupled to partially complete a "boot" process to a point where the computer has detected a "keyboard disconnected" condition and entered a "wait" state. The generated F1 keystroke provided to the computer by the signal generator indicates to the computer that a keyboard is now coupled to the computer, allowing the computer to continue the "boot" process. In the embodiment disclosed, a time delay circuit provides an enabling signal after expiration of the time delay to a latch circuit, a clock signal generator, and a coupling circuit. The output of the latch circuit initially enables loading of a 12-bit shift register with data from a plurality of switches and thereafter switches the mode of the shift register from "load" to "shift." The clock signal clocks the data from the shift register, and the coupling circuitry couples the clock signal and the data from the shift register to the computer as it is clocked from the shift register. Termination circuitry detects the end of the data from the shift register and pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.