Device for interfacing two keyboards to one computer and for automatically connecting the active keyboard to the computer
US5263171A · kind A · utility
9Cited by
12References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1990 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Mar 27, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/023
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This invention pertains to circuitry for automatically coupling up to four keyboards to a single keyboard port of a computer. Switching is accomplished by sensing a clock pulse appearing on one of the keyboard clock pulse lines responsive to a keystroke appearing on one of the keyboards. The clock pulse is applied either to a set input or a reset input of a latch, depending from which of keyboard clock pulses lines the pulse originated. The set or reset condition of the latch evokes a selected voltage potential on the output of the latch, which biases "on" bi-directional switches, coupling one of the keyboards to the computer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.