| 摘要 |
PURPOSE:To improve the reliability for input of data, by discriminating whether an input with a ten-key or an input with an alphameric keyboard, to enabling the input of a discriminated device and to invalidating the input given from another device. CONSTITUTION:A control signal is sent to a decoder 6 from a controller (not shown in the diagram) via an address bus 7. The decoder 6 decodes the control signal and then generates outputs (a) and (b) to activate and inactivate encoders 4 and 5 respectively. When either an alphameric key 2 or a ten-key 3 is operated, the coordinate position of the operated key is detected by an activated encoder and coded to be supplied to a data bus 8. Therefore, the inputs sent from keys which are connected to inactivated encoders are all invalidated. In such a way, the function of a character key needed for a data item to be fed is selectively controlled. This improves the reliability for input of data. |
