摘要 |
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.
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