Interchange system for a bilingual keyboard.

摘要

The proposed system achieves the interchange of a bilingual keyboard of a conventional electronic computer by the use of a switch connected to the serial port of the computer. The switch is mounted between the two signals of the serial port which are not used by peripheral devices for data. One of these signals is kept at logic 1 by the software and can be either Request To Send (RTS)or Data Terminal Ready (DTR). The other signal may be either Clear To Send (CTS) or Data Set Ready (DSR) or Ring Indicator (RI) or Data Carrier Detect (DCD), and is earthed via the resistor R1 as shown in figure 3. The capacitor C1 is used to disconnect and reconnect the switch in order not to create more than one interruption at each press of the switch. On activation by the switch, the software changes the keyboard translation table from one language to the other.