本设计是以八路抢答为基本理念。考虑到依需设定限时回答的功能，利用AT89C51单片机及外围接口实现的抢答系统，利用单片机的定时器/计数器定时和记数的原理，将软、硬件有机地结合起来，使得系统能够正确地进行计时，同时使数码管能够正确地显示时间。用开关做键盘输出，扬声器发生提示。同时系统能够实现：在抢答中，只有开始后抢答才有效，如果在开始抢答前抢答为无效；抢答限定时间和回答问题的时间可在1-99s设定；可以显示是哪位选手有效抢答和无效抢答，正确按键后有音乐提示；抢答时间和回答问题时间倒记时显示，满时后系统计时自动复位及主控强制复位；按键锁定，在有效状态下，按键无效非法。-This design is eight way contest as the basic concept.Considering the time-limited answer according to need to set the function, using AT89C51 MCU and peripheral interface of the answering system, the use of single-chip timer/counter timing and counting principle, the soft and hardware combination, so that the system can correctly time, while the digital tube able to correctly display the time.Switching with the keyboard output, speakers in tips.At the same time the system can realize: the answer, only after the start of the answer is effective, if at the beginning of answer answer answer before the time limit is invalid　question and answer time in 1-99s set　can display which is effective and ineffective players answer answer keys, right after the music cue　answer time and answer questions for inverted timing display, full system timing automatic reset and host a forced reset　key lock, in effective state key invalid, illegal.