1、Introduction of computer
A computer is a machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming. Modern computers have the ability to follow generalized sets of operations, called programs.
计算机是指可以通过计算机编程自动执行算术或逻辑运算的机器。现代计算机能够遵循被称为程序的通用操作集。
- sequence [ˈsiːkwəns] 序列;顺序;、
- arithmetic [əˈrɪθmətɪk]
These programs enable computers to perform an extremely wide range of tasks. A “complete” computer including the hardware, the operating system, and peripheral equipment required and used for “full” operation can be referred to as a computer system.
这些程序使计算机能够执行极其广泛的任务。
“完整”的计算机包括硬件、操作系统和外围设备，它们可以满足计算机系统所需的“全部”操作。该计算机可以称为一个计算机系统。
- peripheral [pəˈrɪfərəl] 外围设备;周边设备
This term may as well be used for a group of computers that are connected and work together, in particular a computer network or computer cluster.
该术语也可以用于连接在一起的一组计算机，特别是计算机网络或计算机集群。
Conventionally, a modern computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information.
传统上，现代计算机至少包括一个处理元件（通常是中央处理单元）和某种形式的存储器。
处理元件执行算术和逻辑运算，并且排序和控制单元可以响应存储的信息来改变操作的顺序。
- Convention [kənˈvenʃn] 习俗;常规;惯例;
- in response to 作为回应;响应；回答；对…有反应
Peripheral devices include input devices (keyboards, mouse, etc.), output devices (monitor screens, printers, etc.). Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.
外围设备包括输入设备（键盘、鼠标等）、输出设备（监视器屏幕、打印机等）。
外围设备允许从外部源获得信息，并且使操作结果得以保存和访问。
- retrieve [rɪˈtriːv] 检索;取回;
- external [ɪkˈstɜːrnl]
2、Computer Hardware
The term hardware covers all of those parts of a computer that are tangible physical objects. circuits, computer chips, graphic cards, sound cards, memory (RAM), motherboards, displays, power supplies, cables, keyboards, printers and mouse are all hardware.
术语“硬件”涵盖计算机中全部有形物理部件。
电路、计算机芯片、图形卡、声卡、存储器（RAM）、主板、显示器、电源、电缆、键盘、打印机和“鼠标”输入设备都是硬件。
- tangible [ˈtændʒəbl] 有形的;实际的;真实的
- circuits [ˈsɜːrkɪts] 电路
- cable [ˈkeɪbl] 电缆
A general purpose computer has four main components: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by buses, often made of groups of wires. Inside each of these parts are thousands to trillions of small electrical circuits which can be turned off or on by means of an electronic switch.
**译文：**通用计算机具有四个主要部件：算术逻辑单元（ALU）、控制单元、存储器以及输入和输出设备（统称为I / O）。这些部件通过总线互连，总线通常由电线组成。这些部件中的每一个都是数千到数万亿的小电路，可以通过电子开关关闭或打开。
- buses 总线
- circuits [ˈsɜːrkɪts] 电路
Each circuit represents a bit (binary digit) of information so that when the circuit is on it represents a “1”，and when off it represents a “0”. The circuits are arranged in logic gates so that one or more of the circuits may control the state of one or more of the other circuits.
**译文：**每个电路表示一位（二进制数字）信息，所以当电路接通时它表示“1”，而当断开时它表示“0”。
电路布置在逻辑门中，这样一个或多个电路可以控制一个或多个其他电路的状态。
- digit 数字
2.1、Input devices
When unprocessed data is sent to the computer with the help of input devices, the data is processed and sent to output devices. The input devices may be hand-operated or automated. The act of processing is mainly regulated by the CPU.
**译文：**输入设备将未处理的数据发送到计算机时，数据将被处理并发送到输出设备。
输入设备既可以手动操作，也可以自动操作。处理行为主要由CPU控制。
Some examples of input devices are computer keyboard, digital camera, digital video, graphics tablet, image scanner, microphone, mouse, touch screen.
**译文：**输入设备的一些示例是：计算机键盘、数码相机、数码视频、图形输入板、图像扫描仪、麦克风、鼠标、触摸屏。
- tablet [ˈtæblət] 板子 药片;
2.2、Output devices
The means through which computer gives output are known as output devices. Some examples of output devices are computer monitor, printer, PC speaker, sound card, video card.
**译文：**计算机提供输出的设备称为输出设备。
输出设备的示例有计算机监视器、打印机、PC扬声器、声卡、视频卡。
2.3、Control unit
The control unit (often called a control system or central controller) manages the computer's various components; it reads and interprets (decodes) the program instructions, transforming them into control signals that activate other parts of the computer.
**译文：**控制单元（通常称为控制系统或中央控制器）管理计算机的各种组件；它读取并解释（解码）程序指令，将它们转换为激活计算机其他部分的控制信号。
- interprets [ɪnˈtɜːrprəts]
A key component common to all CPUs is the program counter, a special memory cell (a register) that keeps track of which location in memory the next instruction is to be read from.
**译文：**所有CPU共有的关键组件是程序计数器，它是一个特殊的存储单元（寄存器）用于跟踪存储器中下一条指令的读取位置。
- register [ˈredʒɪstər]
2.4、CPU and ALU
The control unit, ALU, and registers are collectively known as a central processing unit (CPU). Early CPUs were composed of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor.
**译文：**控制单元，ALU和寄存器统称为中央处理器（CPU）。
早期的CPU由许多独立的组件组成，但自20世纪70年代中期以来，CPU通常构建在称为微处理器的单个集成电路上。
The ALU is capable of performing two classes of operations: arithmetic and logic. The set of arithmetic operations that a particular ALU supports may be limited to addition and subtraction, or might include multiplication, division, trigonometric functions such as sine, cosine, etc., and square roots.
**译文：**ALU能够执行两类操作：算术和逻辑。
特定ALU支持的算术运算集可以限于加法和减法，或者可以包括乘法、除法、三角函数（例如正弦，余弦等）以及平方根。
- trigonometry [ˌtrɪɡəˈnɑːmətri] 三角学
2.5、Memory
A computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered “address” and can store a single number. The information stored in memory may represent practically anything.
**译文：**计算机的存储器可被视为能够放置或读取数字的单元组。每个单元格都有一个编号“地址”，可以存储一个数字。存储在存储器中的信息实际上可以代表任何东西。
Letters, numbers, even computer instructions can be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is the software's responsibility to give significance to what the memory sees as nothing but a series of numbers.
**译文：**字母、数字甚至计算机指令都可以同样轻松地放入存储器中。由于CPU不区分不同类型的信息，因此软件负责解释内存中信息的意义，但对存储器来说，这些信息只不过是一系列数字。
- with equal ease 同样轻松
- differentiate [ˌdɪfəˈrenʃieɪt] 区分;区别;辨别
In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers (28=256); either from 0 to 255 or -128 to +127.
**译文：**在几乎所有现代计算机中，每个存储器单元被设置为以八位组（称为字节）存储二进制数。每个字节能够代表256个不同的数字（28 = 256）；从0到255或-128到+127。
- minus [ˈmaɪnəs] 负号 零下 减去
To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. A computer can store any kind of information in memory if it can be represented numerically.
**译文：**为了存储更大的数字，可以使用几个连续的字节（通常是两个、四个或八个）。当需要负数时，它们通常以二进制补码表示。只要能表示为数字，计算机就能将任何类型的信息存储在存储器中。
- consecutive [kənˈsekjətɪv] 连续的;连续不断的
- two's complement notation 二进制补码 【补足；符号】
The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU.
**译文：**CPU包含一组称为寄存器的特殊存储器单元，在此读取和写入速度比在主存储器更快。根据CPU的类型，通常有两到一百个寄存器。
Computer main memory comes in two principal varieties:
random-access memory (RAM).
read-only memory (ROM).
**译文：**计算机主存有两种主要类型：
随机存取存储器或RAM
只读存储器或ROM
RAM can be read and written to anytime the CPU commands it, but ROM is preloaded with data and software that never changes, therefore the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions.
**译文：**CPU可以在任何时候读取和写入RAM，但因为ROM预装了永不改变的数据和软件，所以CPU只能读取它。ROM通常用于存储计算机的初始启动指令。
2.6、Multiprocessing
Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed only in large and powerful machines such as supercomputers, mainframe computers and servers. Multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers are now widely available.
**译文：**一些计算机被设计为具有多处理配置，它能将其工作分布在多个CPU上，这种技术曾经只用于超级计算机、大型计算机和服务器等功能强大的机器。多处理器和多核（单个集成电路上的多个CPU）个人和便携式计算机现在广泛使用。
3、Unite 1 Exercise
- 计算机硬件 Computer hardware
- 操作系统 operating system
- 外设 peripheral devices
- 微处理器 microprocessor
- 寄存器 registers
- 算数的 Arithmetic
- 逻辑的 logic
- 集成电路 integrated circuit
- 控制器 controller
- 声卡 sound card
- 显卡 Graphics card
- 主板 motherboard
- 打印机 printer
- 多处理器 multiprocessor
- 多核 multi-core
- CPU central processing unit
- 显示器 displays
- 电源 power supplies
- 扬声器 PC speaker
- ALU Arithmetic Logical Unit 算术逻辑部件运算器
- 加减乘除 addition subtraction multiplication division
- RAM random-access memory
- ROM read-only memory
- supercomputers mainframe computers 超级计算机 大型计算机 large and powerful machines