开始键按下后，8个进度指示灯依次点亮，之后开始抢答。4个按键开关代表4个抢答键，由数码管显示最先按下的开关序号，表示此号码抢答成功。若在进度灯全亮之前有任意键被按下，则表示有人犯规！系统结构描述：此系统共包括4个板块，分别是输入板块、计数器板块、数码显示器板块、判断板块，各功能组合一起构成一个完整的抢答器。-Start key is pressed, 8 progress lights were lit, and then answer in the beginning. 4 key switches on behalf of four answer in key pressed by the digital display the switch serial number first, that this number Responder success. If the light all light in the progress before the any key is pressed, it means that some foul! System Architecture Descr iption: This system includes a total of 4 sections, namely the input plate, counter plate, digital display board, determine the plate, the combination of features together constitute a complete Responder.