| 摘要 |
PURPOSE:To improve the operability by providing a means informing the overflow of a key buffer to the user with the warning utilizing sound or light, and releasing automatically the key lock due to the overflow. CONSTITUTION:When a key A is depressed, for example, a corresponding key code is stored to the head of the key buffer KBF of a RAM. Then the key code A is extracted from the KBF to apply control signal CDIS, CPRT to a display device DIS and a printer PRT respectively. Then in depressing keys D, E, F, G, H quickly, a CPU detects that the KBF is occupied when the key H is depressed and supplies the CDIS and the CSPK to the DIS and a speaker SPK, allowing to output a message and a warning sound. Furthermore, when the key code D is executed, since the KBF becomes idle, the said warning is released and the key input is made possible.
|
