| 摘要 |
PURPOSE:To use a single keyboard for a positioning means and keyboard functions by switching the keyboard to a normal mode using it as normal character input and a pointing mode positioning a graphic cursor. CONSTITUTION:A keyboard matrix 1 formed on the keyboard is connected to an encoder 3 for characters and control codes through n signal lines 2 and the output of the encoder 3 is inputted to a microprocessor 5 constituting a CPU as an 8-bit code through a signal line 4. A position vector encoder 6 is also formed in addition to the character/code encoder 3 and multiplexers M1, M2 for selectively switching signal lines 2, 4 to the encoders 3, 6 and a control circuit 7 for controlling these multiplexers M1, M2 are also formed. When the multiplexers M1, M2 are controlled by the control circuit 7 to select the encoder 6, the pointing (positioning) mode of the graphic cursor is used, and in the other case, i.e. when the encoder 3 is selected by the multiplexers M1, M2, the normal mode inputting a character or the like from the keyboard is used.
|
