目前用户较多的长城0520系列微机多数用于企业管理,机上带有大容量的硬磁盘存贮器,没有锁闭装置,保密不方便。一方面可随便开机启动,硬盘上的内容很容易被调用;另一方面,当计算机处于开机状态或正在运行较长的程序,操作人员又不能临时离开现场。为了解决这两方面问题,可在微机上加装保护装置。实现原理:人向计算机输入信息是通过键盘实现的,当人们在键盘上打键时,信息便被计算机接收、识别,然后做出相应反应。因此只要把键盘与计算机的联络切断,计算机就不能接收到键盘信息,也就不会产生动作,而保持原来状态。从计算机与键盘的接口原理图中看出,当把DA- At present, most users of the Great Wall 0520 Series microcomputer for the majority of computer management, with a large capacity hard disk drive memory, no locking device, confidentiality is not convenient. On the one hand, it can be booted up at will, the content on the hard disk can be easily called; on the other hand, the operator can not leave the scene temporarily when the computer is on or running a long program. In order to solve these two problems, the computer can be equipped with protective devices. To achieve the principle: people to the computer to enter information through the keyboard to achieve, when people hit the keys on the keyboard, the information is received by the computer, identify, and then make the appropriate response. So long as the keyboard and the computer liaison cut off, the computer can not receive the keyboard information, it will not produce action, and maintain the original state. From the computer and keyboard interface schematic shows that when the DA-