We build computer to solve problems.Early computer solved mathematical and engineering problems，and later computers emphasized information processing for business applications.T-
oday，computers also control machines as diverse as automobile engines，robots，and microwave ovens. A computer system solves a problem from any of these domains by accepting input，processing it，and producing output. Fig. 1-1 illustrates the function of a computer system.
Computer systems consist of hardware and software. Hardware is the physical part of the system. Once designed，hardware is difficult and expensive to change. Software is the set of programs that instruct the hardware and is easier to modify than hardware. Computers are valuable because they are general-purpose machines that can solve many different kinds of problems，as opposed to special-purpose machines that can each solve only one kind of problem. Different problems can be solved with the same hardware by supplying the system with a different set of instructions.that is，with different software.
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翻译:
计算机组成原理
计算机硬件
人们为解决问题而制造计算机。早期的计算机解决的是数学和工程问题，后来计算机着重解决商业应用中的信息处理问题。如今，计算机还用来控制如
汽车发动机、机器人和微波炉等各式各样的机器。
计算机系统解决上述这些领域中的任何一个问题都是通过接收输入、处理问题和生成输出来实现的。图1-1说明了计算机系统的功能。
计算机系统由硬件和软件组成。硬件是系统的物理部分。硬件一旦设计完毕，要修改是困难的，并且花费也大。软件是指挥硬件的程序集合，比硬件容易修改。计算机之所以有用，是因为它们能解决很多不同类型的问题，是通用的机器。相对而言，每种专用机只能解决一类问题。通过为系统配备不同的指令系统，也就是配备不同的软件，能用同一硬件去解决不同的问题。