| 摘要 |
An interface switching device is connected to a keyboard unit and a computer. Two data lines, a power-supply line, and a ground line, which are provided at the interface switching device, are respectively connected to a data line, a clock line, a power-supply line, and a ground line, which are provided at the keyboard unit. An unused line is connected to an identification line. At the computer, the unused line, and the power-supply line or the ground line, are short-circuited. When the interface switching device is connected, a keyboard is notified of a voltage as identification information which is fixed at a power-supply voltage or zero volts.
|
