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目前,单板微型计算机在工业过程控制和许多专用设备中得到了广泛的应用。用户的应用程序一般是自己设计的,而执行这个程序往往需要在单板微型计算机的键盘上按“GO”、“×”、“×”、“×”、“×”、“CR”等键,××××是这个应用程序的入口地址。要将这些键放在专用设备的面板上,而且每次执行都要按这六个键,显得相当的累赘和费时。有没有办法只按一个键就能使计算机开始执行程序呢?为解决这个问题,我们试制了一个如下图所示的单板微型计算机自动按键电路,现将此电路介绍如下。电路中用了两个继电器 J_1和 J_2,四块集成电路C_1(MCI455)、IC_2(74LS293)、IC_3(74LS138)、IC_4,(74LS04)和七只晶体管 BG_1～BG_7。电路的工作过程
Currently, veneer microcomputers are widely used in industrial process control and many specialized equipment. The user’s application is generally designed by himself. To execute this program, you often need to press “GO”, “×”, “×”, “×”, “×”, “CR” on the keyboard of the single board microcomputer , ×××× is the entrance address of this application. To put these keys on the panel of a dedicated device, and each time you press these six keys, it is quite cumbersome and time-consuming. There is no way to press a button to make the computer start executing the program? To solve this problem, we have a trial version of a single-chip micro-computer automatic button circuit, now this circuit are described below. The circuit uses two relays J_1 and J_2, four integrated circuits C_1 (MCI455), IC_2 (74LS293), IC_3 (74LS138), IC_4, (74LS04) and seven transistors BG_1 ~ BG_7. Circuit of the working process