英语翻译Operating system for micro,mini,and mainframe computers

英语翻译
Operating system for micro,mini,and mainframe computers perform many services.These services can be classified either as“external”or“internal”.
The operating system provides external services that help users start programs,manage stored data,and maintain security.You,as the computer user,control these external functions.Using a command-line,menu-driven,or GUI user interface ,an operating system provides you with a way to select the programs you would like to use.The operating system also helps you find,rename,and delete documents and other data stored on disks or tapes.On many,but not all computer systems ,the operating system helps you maintain security by checking your user ID(用户标识) and password ,as well as protecting your data from unauthorized access and revisions(修改).
The operating system provides internal services“behind the scenes”to ensure that the computer system functions efficiently .These internal services are not generally under your control ,but instead are controlled by the operating system itself.The operating system controls input and output,allocates(分配) system resources,manages the storage space for programs and data,and detects equipment failure without any direction from you.

翻译如下:
操作系统在微机,小型机,大型机上提供了各种服务,这些服务可以归为‘内,外’两种.
操作系统提供的‘外部’服务,比如帮助用户运行程序,管理数据和修改安全系数.你作为电脑的使用者可以控制这些‘外部’的功能.你可以通过命令行,菜单,或者图形用户界面（GUI）,操作系统会帮助你去选择你想要运行的程序.同时操作系统会帮助你搜索,重命名和删除文件及其其他储存在磁盘和磁带上的数据.大部分,但是并不是全部的计算机操作系统能帮你修改用户标识和密码,来保护你的数据遭到未授权人的进入和修改.
操作系统提供的‘内部’服务就是保证计算机‘后台’系统的功能能正常使用.这些‘内部’的服务并不在你的控制之下的,而是计算机系统自己控制的.操作系统会替你控制输入输出,分配系统资源,控制存储空间给程序和数据,侦测设备故障.