| 摘要 |
PURPOSE:To allow an operator to input data as the operator intends even when plural keys are pressed at the same time setting a output requesting flag at the resister when respective contents of resisters holding key addresses of 1-N keys which are pressed are not contained in the key address of the last key detection processing. CONSTITUTION:Key addressed from a keyboard (1) are detected and then the detected key addresses are written in three data register parts A1, A2 and A3 of an area A in a RAM (6). Then, the contents of the area A in the RAM (6) are saved in an area B of the same constitution and it is discriminated whether key address written in a data register part B1 is new or not; when so, an output request flag is set in bits of the register part B5 of the area B corresponding to register parts B1-B3. Then, the contents of the area B are transferred to an area (output buffer) of the same constitution after inspection. Further, it is discriminates whether there is an output request flag in a register part C5 of the area C and codes corresponding to key addresses of register parts among register parts C1-C3 where the flag is set are outputted.
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