Chapter 1

Chapter Goals Describe the layers of a computer system Describe the concept of abstraction and its relationship to computing Describe the history of computer hardware( 硬體 ) and software( 軟體 ) Describe the changing role of the computer user Distinguish between systems programmers( 系統程 式 )and applications programmers( 應用程式 )

1-3 2 Computer A device( 裝置 ) Computing Systems A dynamic entity used to solve problems and interact with its environment (PC, PDA, ABS, …) Computing Systems a. Computer Hardware( 電腦硬體 ) b. Computer Software( 電腦軟體 ) c. Data( 資料 ) (information that CS manage) Computing Systems

1-4 3 Hardware( 硬體 ) The physical elements of a computing system (printer( 印表機 ), circuit boards( 電路板 ), chips( 晶片 ), wires( 電線 ), keyboard( 鍵盤 )…) Software( 軟體 ) The programs( 程式 ) that provide the instructions( 指令 ) for a computer to execute Computing Systems What is the difference between hardware and software?

1-5 4 Communication( 通訊層 ) Application( 應用層 ) Operating System( 作業系統 ) Programming( 程式 ) Hardware( 硬體 ) Information( 資訊 ) Layers of a Computing System (like a onion)

1-6 5 Abstraction( 抽象 ) A mental model (a way to think about something) that removes or hides complex details When we are dealing with a layer, we don’t need to think about the details of other layers. -- Each layer plays its own role Use microsoft-word, don’t know how it was written (car vs. engine, abstract painting) This is a key concept. Abstraction will reappear throughout the text – be sure to understand it! Abstraction

1-7 6 Abacus An early device to record numeric values Blaise Pascal Mechanical device to add, subtract, divide & multiply Joseph Jacquard Jacquard’s Loom, the punched card Charles Babbage Analytical Engine Early History of Computing

1-8 7 Ada Lovelace First Programmer, the loop Alan Turing Turing Machine, Artificial Intelligence Testing Harvard Mark I, ENIAC, UNIVAC I Early computers launch new era in mathematics, physics, engineering and economics Before 1951 Early History of Computing

1-9 8 Vacuum Tubes( 真空管 ) Large, not very reliable, generated a lot of heat Magnetic Drum Memory device that rotated under a read/write head Card Readers( 讀卡機 )  Magnetic Tape Drives( 磁 帶 ) Sequential auxiliary storage devices (storage devices external to the computer memory( 記憶體 )) Peripheral devices input devices (keyboard, mouse( 滑鼠 ), …) output devices (monitor( 螢幕 ), printer,..) auxiliary storage devices( 輔助儲存裝置 ) (hard disk( 硬碟 ), …) First Generation Hardware ( )

Transistor( 電晶體 ) Replaced vacuum tube, fast, small, durable, cheap Magnetic Cores Replaced magnetic drums, information available instantly Magnetic Disks( 磁碟 ) Replaced magnetic tape, data can be accessed directly Second Generation Hardware ( )

Integrated Circuits( 積體電路 ) (IC, chip( 晶片 )) Replaced circuit boards, smaller, cheaper, faster, more reliable. Transistors Now used for memory construction Terminal An input/output device with a keyboard and screen Moore’s law ( 莫爾定律 ) The number of circuits (gates) that could be placed on a single integrated circuit (IC) was doubling each year Third Generation Hardware ( )

Large-scale Integration Great advances in chip technology The modified Moore’s law Chip density was doubling every 18 months PCs, the Commercial Market, Workstations Personal Computers were developed as new companies like Apple (Macintosh) and IBM came into being. Workstations emerged (Sun-Unix, Linux, …). Who? When? Never Mind! Fourth Generation Hardware (1971-?)

Parallel Computing( 平行計算 ) Computers rely on a set of interconnected central processing units that increase processing speed. Processors( 處理器 ) can share the same memory unit or each has its own local memory. SIMD single-instruction multiple-data-stream( 單一指令， 多重資料流 ) MIMD multiple-instruction multiple-data-stream( 多重指令， 多重資料流 ) Software for parallel computing vs. sequential computing( 循序計算 ) Parallel Computing

1-14 Networking Workstation( 工作站 ) was designed for networking, but PC didn’t become practical until With the Ethernet( 乙太網路 ) (coaxial cable( 同軸電纜 ) and protocols( 協定 )), small computers could be connected and share resources. A file server connected PCs in the late 1980s. ARPANET( 美國官方的電腦網路, 為 Internet 的前身 ) and LANs (local area network)  Internet TCP/IP (protocol--the correct specification for computers to communicate)

Machine Language( 機器語言 ) Computer programs were written in binary (1s and 0s) Assembly Languages( 組合語言 ) and translators Programs were written in artificial programming languages and were then translated into machine language (assembler) Programmer Changes Programmers divide into application programmers and systems programmers First Generation Software ( )

High Level Languages( 高階語言 ) Use English-like statements and make programming easier. Fortran, COBOL, Lisp are examples. High-Level Languages Assembly Language Machine Languag e Second Generation Software ( ) ＊ compiler 編譯器 ＊ assembler 組譯器 & ＊ written by system programmer & written by application programmers

Third Generation Software ( ) Systems Software( 系統軟體 ) – utility programs, – language translators, – and the operating system (OS), which decides which programs to run and when Time sharing ( 分時共享,computing speed is faster than human processing speed) Separation between Users and Hardware Computer programmers began to write programs to be used by people who did not know how to program Users need no programming knowledge

Application Package Systems Software High-Level Languages Assembly Language Machine Language Third Generation Software ( )

Structured Programming Pascal, C, C++ More powerful operating system UNIX, PC-DOS, Mac (point-and-click graphical interface) New Application Software for Users Spreadsheets, word processors, database management ( 管理 ) systems (Lotus 1-2-3) Fourth Generation Software ( )

Microsoft The Windows operating system, and other Microsoft application programs dominate ( 主導 ) the market Object-Oriented Design( 物件導向設計 ) Based on a hierarchy of data objects (i.e. Java) World Wide Web Allows easy global communication through the Internet New Users Today’s user needs no computer knowledge Traditional computing system ( 傳統的電腦系統 ) 式系統 ) (car, toaster, fan, mp3 player) Embedded System( 嵌入式系統 ) (car, toaster, fan, mp3 player) Fifth Generation Software (1990- present)

Programmer / User Applications Programmer (uses tools) User with No Computer Background Systems Programmer (builds tools) Domain-Specific Programs Computing as a Tool ( 專屬領域程式 )

Computing as a Discipline What can be (efficiently) automated? Four Necessary Skills 1.Algorithmic( 演算法 ) Thinking 2.Representation 3.Programming 4.Design Solve problems with step-by-step procedures Store date with an efficient way

1-23 Is Computer Science a mathematical, scientific, or engineering discipline? 22 What do you think? Computing as a Discipline

Systems Areas of Computer Science Algorithms and Data Structures( 資料結 構 ) Programming Languages( 程式語言 ) Architecture( 結構 ) Operating Systems( 作業系統 ) Software Methodology and Engineering Human-Computer Communication

Application Areas of Computer Science Numerical and Symbolic Computation Databases( 資料庫 ) and Information Retrieval Artificial Intelligence( 人工智慧 ) and Robotics( 機器人學 ) Graphics( 圖論 ) Organizational Informatics( 資訊學組織 ) Bioinformatics( 生物資訊學 )

1-26 Homework Exercises #46, #47, #48, #50, #51, #54 in the textbook Write answers in Chinese