微型计算机的硬件及软件介绍

微型计算机的硬件及软件介绍

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