微型計(jì)算機(jī)的硬件及軟件介紹

　　計(jì)算機(jī)是人類科學(xué)技術(shù)上一項(xiàng)偉大的成就，如今計(jì)算機(jī)的應(yīng)用范圍已經(jīng)從科學(xué)計(jì)算擴(kuò)展到人類社會(huì)的各個(gè)領(lǐng)域。計(jì)算機(jī)之所以如此普及，是由其自身特點(diǎn)所決定的。接下來小編為大家整理了微型計(jì)算機(jī)的硬件及軟件介紹。希望對(duì)你有幫助哦!

　　Computer Hardware

　　A computer is a fast and accurate symbol processing system. It can accept， store， process data and produce output results. A computer can automatically process data without human intervention. However， it must be given a set of instruction to guide it， step by step， through processes. The set of instructions is called a program， The program is stored physically inside the machine， making it a program.

　　All computer systems of interest to us are similar. They contain hardware components for input， central processing unit and output. The system on the small-scale is called a microcomputer or minicomputer. Continuing up the size scale， the mainframe computer is one that may offer a faster processing speed and a greater storage capacity than a typical mini. Finally comes the supercomputer， designed to process complex scientific applications， which is the largest and fastest.

　　Although the capacity of computers' storage locations is varied， every computer stores numbers， letters， and other characters in a coded form. Every character in the storage is represented by a string of 0s and 1s， the only digits founded in the binary numbering system. BCD and ASCII are popular computer codes.

　　Memory

　　Primary memory is known as random access memory (RAM) and simple named memory. It is the storage area within the computer that holds programs and data during processing. Memory is only temporary storage area; when processing is complete， memory is cleared. The user needs to load or enter data and programs into the computer memory when using any application on the computer.

　　Different computers have different amounts of memory space， referred to as memory size， ranging from 4， 8 megabytes to 64megabytes. Today， the memories of some microcomputers even can be expandable to hundreds of megabytes.

　　CPU

　　CPU is the abbreviation of Central Processing Unit， which is the heart of a computer like the head of a family. Once the power of a computer is turned on， all the behaviors are under the control of CPU. CPU is in an iron box together with other devices such as disk drives， a main memory and a switching power supply etc. In Chinese， the iron box is conventionally called the mainframe. On the back of the mainframe box， there are various ports， with which CPU may be linked with input and output devices.

　　Computer software

　　Most people think of software as all of the amazing application programs available today for microcomputers. But there are other forms of computer software that make it possible to use application programs. Software is the collective name for all the programs and instructions that direct a computer's operations. Generally software can be divided into three types： system software， application software and support software， system software monitors and controls the system's hardware. Application software performs specific tasks for the user. Support software is a series of software， which support development and maintenance of other software. Software is created through the use of programming languages.

　　The computer Language

　　The role of a program is to deliver user's intention to a computer and direct it to work. That is to say， a program is a dialogue tool for interacting between a man and a computer， as well as a bridge to transmit information. In general， the characters， phases and their syntax rules for programming are generally called “programming language”。

　　Programming languages are divided into three types： machine language， which is also called an instruction system， is the only one used directly by computers. The assembler language is a kind of symbolic language. It adopted some mnemonic symbols which can show the instructional functions to present the content of the program. The high-level language is a programming language based on English. Its operators and expressions are similar to ordinary mathematical formulas. General users can easily master a high-level language and make programs in it.

　　Programming

　　Programming is， at its simplest， the way people tell computers what to do， when to do it， and how to do it. A program is a specific set of instructions written by one or more people， which direct the action of a computer system. It may be a very simple or complicated set of instructions. It may be written by a beginning computer user or by a top computer expert. It may be written in simple English or in a language spoken only by computers. Just as writing a fiction， programming is a process of creating art.

　　What is Object Oriented Programming?

　　Object oriented programming (OOP) is a new way of approaching the job of programming that differs from traditional programming because it uses objects as data structures to enhance productivity， simplify programming， get reusability and improve software reliability. All object oriented programming languages have three characteristics in common： objects， polymorphism and inheritance. Let's take a look at these concepts.

　　Object is a data structure that contains both structured information and related operations. An object can contain other objects. In this way， the object is given both data properties and behaviors， and so object oriented programs can better reflect the real world they are trying to simulate. Polymorphism essentially means that one name can be used for several related but slightly different purposes. Inheritance is the process by which one object can acquire the properties of another object. This is important because it supports the concept of classification. For example， a red delicious apple is a part of the classification apple， which in turn is a part of the fruit class， which is under the larger class food.

　　計(jì)算機(jī)的硬件

　　計(jì)算機(jī)是一種快速、精確的符號(hào)加工系統(tǒng)，它能接收、存儲(chǔ)、處理數(shù)據(jù)并產(chǎn)生輸出結(jié)果。計(jì)算機(jī)可以在不需要人工干預(yù)的情況下自動(dòng)處理數(shù)據(jù)，然而必須給它一組指令去引導(dǎo)它，使之逐步地通過一個(gè)個(gè)處理過程，這組指令稱之為程序。

　　我們目前所使用的計(jì)算機(jī)，其硬件成分都是相似的，它們的硬件設(shè)備均包含輸入設(shè)備，中央處理器和出設(shè)備。小規(guī)模的系統(tǒng)叫做微型計(jì)算機(jī)或小型計(jì)算機(jī)。隨著規(guī)模的增加，形成了大型計(jì)算機(jī)，它比一般的小型計(jì)算機(jī)有更快的處理速度和更大的存儲(chǔ)容量。最后是超型計(jì)算機(jī)，它用于處理更復(fù)雜的科學(xué)問題，這種計(jì)算機(jī)規(guī)模最大、速度最快。

　　盡管計(jì)算機(jī)存儲(chǔ)單元的存儲(chǔ)能力不同，但是每一個(gè)計(jì)算機(jī)都以編碼的形式存儲(chǔ)數(shù)字、字母和其它的字符。每一個(gè)存儲(chǔ)的字符都被表示成0或1組成的串，0和1是二進(jìn)制編碼系統(tǒng)中僅有的數(shù)字。BCD碼和ASCII碼都是流行的計(jì)算機(jī)代碼。

　　附注：BCD (Binary-Coded Decimal)：二進(jìn)制編碼的十進(jìn)制

　　附注：ASCII(American National Standard Code for Information Interchange)：美國(guó)國(guó)家信息交換標(biāo)準(zhǔn)代碼

　　內(nèi)存

　　主存儲(chǔ)器又稱為隨機(jī)存取存儲(chǔ)器，簡(jiǎn)稱內(nèi)存。它是計(jì)算機(jī)在處理過程中存儲(chǔ)程序和數(shù)據(jù)的區(qū)域。內(nèi)存只是一個(gè)臨時(shí)的存儲(chǔ)區(qū)域，處理完成后內(nèi)存就被清空了。用戶在使用應(yīng)用程序需將數(shù)據(jù)和程序調(diào)入計(jì)算機(jī)內(nèi)存。

　　不同的計(jì)算機(jī)具有不同的內(nèi)存空間，內(nèi)存空間是指內(nèi)存的大小，從4兆、8兆到32兆不等。目前有些微機(jī)的內(nèi)存甚至可以擴(kuò)充到上百兆。

　　中央處理單元

　　CPU是中央處理單元的英文縮寫。它是計(jì)算機(jī)的心臟，好比一家之主一樣。計(jì)算機(jī)一旦通電運(yùn)行，則所有的行為都要在它的控制之下運(yùn)行。CPU同其它設(shè)備如磁盤驅(qū)動(dòng)器、內(nèi)存和開關(guān)穩(wěn)壓電源等被裝在一個(gè)鐵箱子中。 在中文里，這個(gè)箱子被習(xí)慣地稱為主機(jī)。在主機(jī)箱的背后， 有各種端口，用來溝通CPU 和其它輸入輸出設(shè)備的聯(lián)系。

　　計(jì)算機(jī)軟件

　　很多人認(rèn)為軟件就是目前微機(jī)上使用的所有令人驚奇的應(yīng)用程序。但是還有一些其它形式的用以支持應(yīng)用程序運(yùn)行的計(jì)算機(jī)軟件。 軟件是所有指揮計(jì)算機(jī)操作的指令和程序的統(tǒng)稱。 通常軟件被劃分成三類： 系統(tǒng)軟件、 應(yīng)用軟件和支撐軟件。 系統(tǒng)軟件負(fù)責(zé)監(jiān)視和控制計(jì)算機(jī)硬件;應(yīng)用軟件為用戶完成具體的任務(wù); 支撐軟件是支撐其它軟件的開發(fā)與維護(hù)的一系列軟件。軟件都是使用程序設(shè)計(jì)語言創(chuàng)造出來的。

　　計(jì)算機(jī)語言

　　程序的作用就是向計(jì)算機(jī)轉(zhuǎn)達(dá)用戶的意圖，指揮計(jì)算機(jī)工作， 也就是說，程序是人機(jī)對(duì)話的工具，是人與電腦交流信息的橋梁。 通常，程序設(shè)計(jì)所使用的符號(hào)、短語及其語法規(guī)則通稱為程序設(shè)計(jì)語言。

　　程序設(shè)計(jì)語言分為機(jī)器語言、匯編語言和高級(jí)語言三類。機(jī)器語言是計(jì)算機(jī)唯一能直接使用的語言，也叫做計(jì)算機(jī)指令系統(tǒng);匯編語言是一種符號(hào)語言，它采用一些能反映指令功能的助記符表達(dá)程序的內(nèi)容;高級(jí)語言是一種以英文為基礎(chǔ)的設(shè)計(jì)語言， 其中的運(yùn)算符和表達(dá)式都和通常的數(shù)學(xué)公式類似。 一般用戶也能很容易地掌握一種高級(jí)語言， 并可以用它來編制程序。

　　程序設(shè)計(jì)

　　程序設(shè)計(jì)，簡(jiǎn)單地說， 就是人們告訴計(jì)算機(jī)做什么，什么時(shí)候做以及怎樣做的方式。 一個(gè)程序就是一組指令的集合，由一個(gè)或多人編寫，用于指導(dǎo)計(jì)算機(jī)系統(tǒng)的動(dòng)作。這個(gè)指令的集合可能非常簡(jiǎn)單，也可能十分復(fù)雜。它可能是一個(gè)初學(xué)計(jì)算機(jī)的用戶編寫的也有可能是由高級(jí)計(jì)算機(jī)專家編寫的。 它可以用簡(jiǎn)單的英語編寫，也可以用只有計(jì)算機(jī)“說”的語言編寫。如同寫小說一樣，程序設(shè)計(jì)也是一個(gè)藝術(shù)創(chuàng)造的過程。

　　何為面向?qū)ο蟮某绦蛟O(shè)計(jì)

　　與傳統(tǒng)的編程方法不同， 面向?qū)ο蟮某绦蛟O(shè)計(jì)(OOP)是一種新的編程方法，它使用對(duì)象作為其數(shù)據(jù)結(jié)構(gòu)以提高生產(chǎn)率，簡(jiǎn)化程序設(shè)計(jì)，獲得可復(fù)用性和提高軟件的可靠性。所有的面向?qū)ο蟮某绦蛟O(shè)計(jì)語言都具有對(duì)象、多態(tài)和繼承的特點(diǎn)。 讓我們來看一下這幾個(gè)概念。

　　對(duì)象是一種數(shù)據(jù)結(jié)構(gòu)。 它既含有結(jié)構(gòu)化的信息又含有相關(guān)的操作。一個(gè)對(duì)象可以含有另外一個(gè)對(duì)象。通過這種方式，對(duì)象被賦予數(shù)據(jù)特征和行為，因此，使用面向?qū)ο蟪绦蚰軌蚋玫胤从吵绦蛴M的現(xiàn)實(shí)世界。多態(tài)本質(zhì)上就是使用一個(gè)名字來描述幾個(gè)相關(guān)但又有所區(qū)別的目的。繼承就是一個(gè)對(duì)象獲得另一個(gè)對(duì)象的特征的過程。這一點(diǎn)非常重要，因?yàn)樗С址诸惖母拍?。例如，一個(gè)美味可口的紅蘋果是蘋果類的一員，而蘋果又是水果類的一部分，再進(jìn)一步，水果又是食物這更高一級(jí)類的一部分。