Introduction to Computer Science Chapter I. Big Picture

Introduction to Computer Science Chapter I. Big Picture Lynn Choi Korea University Class Information Lecturer Prof. Lynn Choi, School of Electrical Eng. Phone: 3290-3249, 공학관 411, lchoi@korea.ac.kr TA: 이상훈, 3290-3896, smile97@korea.ac.kr Time Tues/Thur 10:30pm – 11:45pm, Office Hour: Thur 4pm – 5pm Place 창의관 117 Textbook “Computer Science Illuminated”, The 3rd Edition, Nell Dale and John Lewis, Jones and Barlett, 2007. References “Foundations of Computer Science”, The 2nd Edition, Behrouz Forouzan and Firouz Mosharraf, Thomson, 2004. Class homepage: http://it.korea.ac.kr : slides, announcements Computer: What is a Computer? What’s Inside a Computer System? Computer Components What’s inside a CPU? Pentium 4 Processor Die on 0.18 micron (42M transistors) 400MHz system bus Advanced Transfer Cache Pipeline Trace cache FP/MMX Logic Level : Gates Circuit Level: Transistors CMOS NAND Gate What is Computer? Computer A kind of digital system All the information is represented, stored, and processed in binary digits. A programmable device Processor inside – microprocessors, digital signal processor (DSP), microcontroller, etc. Processors can be programmed using their machine instructions. Hardware The physical elements of a computing system Printer, mother boards, wires, keyboard, CPU, DRAM, HDD, CD-ROM, network cards, .. Software The programs that provide the instructions for a computer to execute Operating systems: Windows, Linux, MacOS Translators: C compilers, Java interpreters, FORTRAN compilers Applications; Internet Explorer, Microsoft Office, flight simulators, games, etc. Layers of a Computer System Abstraction Abstraction A mental model that removes complex details This is a key concept. Abstraction will reappear throughout the text – be sure you understand it! Internal details Abstraction Abstract view Layers of a Computer System Information Layer How to represent numbers, texts, images, audios, and videos All the information is represented using binary digits, i.e. bits (0s and 1s) Hardware Layer Physical components; CPU, memory, HDD, motherboards, gates and circuits Programming Layer Machine language, assembly language, high-level language, software Operating System Layer Interact with users, schedule programs, and manage hardware resources Application Layer Solve real-world problems Run application programs to use computer’s abilities to perform various tasks Communication Layer Computers are connected into networks so that they can share information and resources Layers of Software Class Information Content of this class Introduction: Big Picture (Ch. 1) Information Layer: how information is represented in a computer (Ch. 2, 3) Hardware Layer: gates and circuits (Ch. 4-5) Programming Layer (Ch. 6-9) Machine language, assembly language, high-level programming languages Data structures and algorithms Operating System Layer (Ch. 10-11) Process management, file system Application Layer (Ch. 12-14) AI, graphics, databases, simulation Communication Layer (Ch. 15-16) Computer Networks World Wide Web Grading Midterm: 35% Final: 40% Homework, Project: 25% Class participation: + 10% Areas of Computer Science Systems Area Algorithms and Data Structures Programming Languages and Compilers Computer Architecture Operating Systems Software Engineering Human-Computer Interaction Computer Networks Application Area Numerical Computation Databases Artificial Intelligence and Robotics Graphics Bioinformatics World Wide Web Games History of Computing Lynn Choi Dept. of Computer and Electronics Engineering History of Computing Abacus: appeared around 16th century BC Developed in Babylonia Imported to China and improved substantially around 1200’s BC Modern abacus is an improved variety from Japan after the World War II Pascal’s Arithmetic Machine (Pascaline) French mathematician, physicist, theologian, philosopher The first mechanical calculator Developed in 1642 (only at 19 years old) only add/subtract 10 toothed wheels Leibniz’s Calculator Developed in 1673 based on Pascal’s machine Can do add/subtract/multiply/divide History of Computing Analytic Engine The first autonomic computing machine Designed by Charles Babbage in 1833 Like today’s computer, it has central processing unit, memory storage, software instructions, punch card inputs, and printed outputs 50 decimal digit calculations Memory of 1000 digits Operated by steam power Some people refer Babbage “the Father of Computing” Ada Lovelace The first programmer using the Analytic Engine Subroutines, loops, conditional jumps History of Computing Turing Machine A mathematical computing model proposed by Alan M. Turing in 1936 Abstract symbol manipulating device that can simulate the logic of any computer Theoretical background to modern computers ACM Turing Award – the Novel prize in Computer Science Consists of infinite linear tape, read/write head, control unit Mapping table gives state transition functions, i.e. given a state and a symbol, erase symbol/rewrite symbol, move R/W head to left or right, and go to a new state Contribute to the following concepts Stored program concept High-level programming language concepts Recursive function concept ENIAC ENIAC ENIAC (Electronic Numerical Integrator And Computer) 1st general-purpose electronic computer Designed by John Mauchly and John Presper Eckert at Upenn Funded by US BRL (Ballistic Research Lab) to develop range and trajectory tables for new weapons Until then, BRL employee more than 200 people with desktop calculators to solve the necessary ballistics equations The proposal accepted in 1943, the machine completed in 1946, and dismantled in 1955 Used for H-bomb research Characteristics 30 tons, 15000 square feet, 18000 vacuum tubes, 140 KW power dissipation Decimal machine 20 accumulators each holding 10-digit decimal number Each digit is represented by a ring of 10 vacuum tubes Manually programmed by setting switches and plugging/unplugging cables 5,000 additions per second ENIAC The Von Neumann Machine - IAS IAS By von Neumann at the Princeton Institute for Advanced Studies Von Neumann was a consultant on the ENIAC project Stored program concept The ability to store its instructions in its internal memory and process them in its arithmetic unit, so that in the course of a computation they may be not just executed but also modified at electronic speeds Started in 1946 and completed in 1952 All modern computer systems are called Von Neumann machines The same structure and the same functions Processor, memory, inputs, and outputs Stored program concept, PC, MAR 1000 x 40 bit words Binary number 2 x 20 bit instructions The Von Neumann Machine & IAS Staff of IAS Computer Project Von Neumann - Biography Born 28 December 1903, Budapest, Hungary; Died 8 February 1957, Washington DC; Brilliant mathematician, synthesizer, and promoter of the stored program concept, whose logical design of the IAS became the prototype of most of its successors - the von Neumann Architecture. Von Neumann was a child prodigy, born into a banking family is Budapest, Hungary. When only six years old he could divide eight-digit numbers in his head. He received his early education in Budapest, under the tutelage of M. Fekete, with whom he published his first paper at the age of 18. Entering the University of Budapest in 1921, he studied Chemistry, moving his base of studies to both Berlin and Zurich before receiving his diploma in 1925 in Chemical Engineering. He returned to his first love of mathematics in completing his doctoral degree in 1928. he quickly gained a reputation in set theory, algebra, and quantum mechanics. At a time of political unrest in central Europe, he was invited to visit Princeton University in 1930, and when the Institute for Advanced Studies was founded there in 1933, he was appointed to be one of the original six Professors of Mathematics, a position which he retained for the remainder of his life. At the instigation and sponsorship of Oskar Morganstern, von Neumann and Kurt Gödel became US citizens in time for their clearance for wartime work. There is an anecdote which tells of Morganstern driving them to their immigration interview, after having learned about the US Constitution and the history of the country. On the drive there Morganstern asked them if they had any questions which he could answer. Gödel replied that he had no questions but he had found some logical inconsistencies in the Constitution that he wanted to ask the Immigration officers about. Morganstern strongly recommended that he not ask questions, just answer them! During 1936 through 1938 Alan Turing was a graduate student in the Department of Mathematics at Princeton and did his dissertation under Alonzo Church. Von Neumann invited Turing to stay on at the Institute as his assistant but he preferred to return to Cambridge; a year later Turing was involved in war work at Bletchley Park. This visit occurred shortly after Turing's publication of his 1934 paper "On Computable Numbers with an Application to the Entscheidungs-problem" which involved the concepts of logical design and the universal machine. It must be concluded that von Neumann knew of Turing's ideas, though whether he applied them to the design of the IAS Machine ten years later is questionable. [5] •http://ei.cs.vt.edu/~history /VonNeumann.html Commercial Computers in 1950’s Sperry-Rand Corporation Eckert & Mauchly Computer Corporation was founded in 1947 Merged with Sperry-Rand Corporation UNIVAC (Universal Automatic Computer) I Used for (population) census in 1950 UNIVAC II Higher performance, larger memory, upward compatibility Provides backward compatibility from UNIVAC and secure customer base IBM Start as an equipment company for punch card IBM 701, 1953 The first commercial stored program computer Used for scientific application IBM 702, 1955 Business applications Computer Generations 1st generation computers Vacuum tube, 1946-1957, 40K operations/sec 2nd generation computers Transistor, 1958-1964, 200 K operations/sec Smaller, cheaper, less heat dissipation William Shockley et al. in 1947 at Bell Labs 3rd generation computers SSI, MSI, 1965-1971, 1 M operations/sec 4th generation computers LSI, 1972-1977, 10 M operations/sec 5th generation computers VLSI, 1978 to date, 100 M operations/sec Advances in Intel Microprocessors 80 81.3 (projected) SPECInt95 Performance Moore’s law – Intel’s co-founder 70 “The number of transistors that could be put on a single chip is doubled every 18 months.”, 1965 Memory capacity quadruples every 3 year The number of transistors and the performance of a microprocessor is quadrupled every 3 year Pentium IV 2.8GHz (superscalar, out-of-order) 60 50 40 45.2 (projected) Pentium IV 1.7GHz (superscalar, out-of-order) 24 Pentium III 600MHz (superscalar, out-of-order) 8.09 11.6 PPro 200MHz (superscalar, out-of-order) 30 3.33 Pentium 100MHz 1 (superscalar, in-order) 80486 DX2 66MHz (pipelined) 20 10 Pentium II 300MHz (superscalar, out-of-order) 1992 1993 1994 1995 1996 1997 1998 1999 2000 2002 Power PC and Sony PlayStation III Microprocessor Performance Curve