Chapter 1 Computer Basics 1.1 History of the Computer A computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention. abacus Ⅰ. Prehistory /ˈæbəkəs/ n. 算盘 The abacus, which is a simple counting aid, might have been invented in Babylonia(now Iraq) in the fourth century BC. It should be the ancestor of the modern digital calculator. Figure 1.1 Abacus Wilhelm Schickard built the first mechanical calculator in 1623. It can loom work with six digits and carry digits across columns. It works, but never /lu:m/ makes it beyond the prototype stage. n. 织布机 Blaise Pascal built a mechanical calculator, with the capacity for eight digits. However, it had trouble carrying and its gears tend to jam. punch cards Joseph-Marie Jacquard invents an automatic loom controlled by punch 穿孔卡片 cards. Difference Engine Charles Babbage conceived of a Difference Engine in 1820. It was a 差分机 massive steam-powered mechanical calculator designed to print astronomical tables. He attempted to build it over the course of the next 20 years, only to have the project cancelled by the British government in 1842. 1 新编计算机专业英语 Analytical Engine Babbage’s next idea was the Analytical Engine-a mechanical computer which 解析机（早期的机 could solve any mathematical problem. It used punch-cards similar to those used 械通用计算机） by the Jacquard loom and could perform simple conditional operations. countess Augusta Ada Byron, the countess of Lovelace, met Babbage in 1833. She /ˈkaʊntɪs/ described the Analytical Engine as weaving “algebraic patterns just as the n. 女伯爵； Jacquard loom weaves flowers and leaves.” Her published analysis of the 伯爵夫人 Analytical Engine was our best record of its programming potential. In her outline analysis report, she has outlined the fundamentals of computer programming, /ˈautlain/ including data analysis, looping and memory addressing. v. 概述 Ⅱ. Electronics era Konrad Zuse, a German engineer, completed the first general purpose boolean programmable calculator in 1941. He pioneered the use of binary math and /ˈbu:liən/ boolean logic in electronic calculation. a. 布尔数学体系的 ENIAC (Electronic Numerical Integrator and Computer) might be the ENIAC most influential of the early computer-like devices. It was developed by J. 电子数字积分 Presper Eckert and John Mauchly at the University of Pennsylvania. The 计算机 project began in 1943 and was completed in 1946. The machine was huge; it weighed 30 tons and contained over 18,000 vacuum tubes. The ENIAC is shown in Figure 1.2. Figure 1.2 ENIAC The ENIAC was a major advancement for its time. It was the first general-purpose, electronic computing machine and was capable of performing thousands of operations per second. It was controlled, however, by switches and plugs that had to be manually set. Thus, although it was a general-purpose electronic device, it did not have a stored program. Therefore, it did not have all the characteristics of a computer. While working on the ENIAC, Eckert and Mauchly were joined by a brilliant mathematician, John von Neuman. Together, they developed the EDVAC idea of a stored program computer. This machine, called the Electronic 电子离散变量自动 Discrete Variable Automatic Computer or EDVAC, was the first machine 计算机 2 Chapter 1 Computer Basics whose design included all the characteristics of a computer. However, it has not been completed until 1951. Before the EDVAC was finished, several other machines were built that EDSAC incorporated elements of the EDVAC design of Eckert, Mauchly and von 电子延迟存储自动 Neuman. One was the Electronic Delay Storage Automatic Computer or 计算器 EDSAC, which was developed in Cambridge, England. It first operated in May of 1949 and might be probably the world’s first electronic BINAC stored-program, general-purpose computer to become operational. The first 二进制自动计算机 computer operated in the United States was the Binary Automatic Computer or BINAC, which became operational in August of 1949. UNIVAC Like other computing pioneers before them, Eckert and Mauchly successed 通用自动计算机 to build the Universal Automatic Computer or UNIVAC successfully in 1950. This machine was the first commercially available computer. The UNIVAC began the modern of computer use. Ⅲ. Computer Generations vacuum tube 1. First-Generation Computers: 1951～1958 真空管 First-generation computers were characterized by the use of vacuum tubes as their principal electronic components. Vacuum tubes were bulky and produce a air-conditioning lot of heat, so first-generation computers were large and required air-conditioning 空调 to keep them cool. In addition, because vacuum tubes did not operate very fast, evolve these computers were relatively slow. At the same time that hardware was /iˈvɔlv/ evolving, software was developing. The first computers were programmed in v. 演变，进化 machine language, but during the first computer generation, the idea of programming language translation and high-level languages occurred. Also, the first simple operating systems became available with the first-generation computers. transistor 2. Second-Generation Computers: 1959～1963 /trænˈsistə/ In the second generation of computers, transistors replaced vacuum n. 晶体管 tubes. Although invented in 1948, the first all-transistor computer did not become available until 1959. Transistors are smaller and less expensive than vacuum tubes, and they operate faster and produce less heat. Hence, with second-generation computers, the size and cost of computers decreased, their COBOL speed increased, and their air-conditioning needs were reduced. Common Business- Software also continued to develop during this time. Many new Oriented Language programming languages were designed, including COBOL in 1960. More 面向商业的通用 and more businesses and organizations were beginning to use computers for 语言 their data processing needs. 3. Third-Generation Computers: 1964～1970 The technical development that marks the third generation of computers 3 新编计算机专业英语 integrated circuit is the use of integrated circuit or IC in computers. An integrated circuit is a 集成电路 piece of silicon (a chip) containing numerous transistors. One IC replaces silicon many transistors in a computer; result in a continuation of the trends begun /ˈsilikən/ in the second generation. These trends include reduced size, reduced cost, n. 硅 increased speed, and reduced need for air-conditioning. The principal software development during the third computer generation was the increased sophistication of operating systems. Many of the features of modern operating systems began to appear. These include minicomputer multiprogramming, virtual memory, and time-sharing. So, the third computer /ˈminikəmˈpju:tə/ generation was also the time when minicomputers became widespread. n. 小型计算机 4. Fourth-Generation Computers: 1971～now The fourth generation of computers is characterized by more and more transistors being contained on a silicon chip. First there was Large Scale Integration (LSI), with hundreds and thousands of transistors per chip, then came Very Large Scale Integration (VLSI), with tens of thousands and hundreds of thousands of transistors. The trend continues today. gradually During the fourth computer generation, operating systems were /ˈgrædjʊəlɪ/ gradually improved, and new languages were designed. Database software ad. 逐步地,渐渐地 became widely used during this time. The most important trend, however, resulted from the microcomputer revolution. Packaged software became widely available for microcomputers so that today most software is from scratch purchased, not developed from scratch. 〈非正〉从头做起 1.2 Computer Architectures architecture /5B:kitektFE/ In computer science and engineering, computer architecture refers to n. 体系结构 specification of the relationship between different hardware components of a computer system. It may also refer to the practical art of defining the component structure and relationship of the subcomponents of a computer. At a high /kEm5pEunEnt/ level, computer architecture is concerned with how the Central Processing n. 成分；组件；部 Unit (CPU) acts and how it accesses computer memory. 件 An early example of an architectural definition of a computer was John Von Neumann's 1945 paper, First Draft of a Report on the EDVAC, which described an organization of logical elements. IBM used it to develop the IBM 701, the company's first commercial stored program computer, delivered in early 1952. subcategory The art of computer architecture has three main subcategories: /5sQb5kAti^Eri/ (1) Instruction set architecture (ISA): Instruction set architecture (ISA) is n. 子类 the interface between the software and hardware. The ISA is the code that a central processor reads and acts upon. It is the machine language (or assembly 4 Chapter 1 Computer Basics language) and do not understand high level languages, including the instruction set, word size, memory address modes, processor registers, and address and data formats. A processor only understand instructions encoded as binary numbers. (2) Microarchitecture: Microarchitecture also known as computer organization describes the data paths, data processing elements and data storage elements, and describes how they should implement the ISA. In computer engineering, microarchitecture is the way a given instruction set architecture (ISA) implemented on a processor. A given ISA may be implemented with different microarchitectures. Implementations might vary due to different goals of a given design or due to shifts in technology. Computer architecture is the combination of microarchitecture and instruction set design.