COMS 647: Communication Technology

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1 COMS 647: Communication Technology

2 Plan Presentation Sign-up Historical Context History of Computing History of the Internet Preview

3 Plan Presentation Sign-up

4 Introduction Communication Technology Two technological components: computers networks

5 Introduction Demystify Technology Terminology History Basic Operations

6 Computer

7 Computer Definitions Computer = (n.) a device that computes Computing = (v.) to represent data in a physical object of some kind and get a result by manipulating this object in some way 4 basic operations of all computers Input Processing Output Storage IPOS cycle

8 Computer IPOS cycle - Input

9 Computer IPOS cycle - Input Keyboard Microphone Mouse Scanner

10 Computer IPOS cycle - Processing

11 Computer IPOS cycle - Processing Microprocessor Central Processing Unit (CPU)

12 Computer IPOS cycle - Output

13 Computer IPOS cycle - Output Monitor Speakers Printer

14 Computer IPOS cycle - Storage

15 Computer IPOS cycle - Storage RAM/ROM Hard Drive USB Drive CD /DVD

16 Computer Computer System Hardware Physical components; elements of the IPOS Cycle The part of a computer that you can kick Software Programs or Applications Indicate how the physical components operate Control the IPOS Cycle

variations Digital Encode data as discrete elements.

17 Data Representation Analog / Digital Analog Encode data as a function of changes of a continuous scale; represented mechanically by spatial differences across a ruler or gear or electrically with voltage variations Digital Encode data as discrete elements. Digital computers use two discrete variables (0,1); represented either mechanically by a two position switch or electrically with changes in voltage (on/off) or electric charge (+/-)

18 Data Representation Digital G. W. F. Leibniz Binary numbers Mathematics with 2 variables George Boole Boolean Algebra Reduce all logical processing to three operations AND, OR and NOT Digital Computer = series of logic gates. Operate according to Boolean algebra to determine the value of an output signal (one or zero).

Data Representation Numbering system Digital Computer Computers only have two possible states by which to represent data - high or low power circuit Digital computers

19 Data Representation Numbering system Digital Computer Computers only have two possible states by which to represent data - high or low power circuit Digital computers use base 2 or binary numbers Base 2 Count 0-1; at 2, carry over into the next column Perfect system for computers 0 = low power circuit (off) 1 = high power circuit (on)

20 Data Representation Numbering system Bit = Binary Digit Smallest unit of information a computer can use Byte 8 bits possibilities; baseline measure for data size

21 Data Representation Character Codes Translate between digital world of the computer and the human world of decimal numbers and letters ASCII American Standard Code for Information Interchange Examples dog = cat = Binary encoder

22 History of Computing

23 History of Computing Topics Mechanical Computers Electronic Computers Computer Generations (1-4) General Features

History of Computing Mechanical Computers Abacus Popular and accurate device 4000+ years in service Operation Beads on wire = figures

24 History of Computing Mechanical Computers Abacus Popular and accurate device years in service Operation Beads on wire = figures (data) User follows a set of rules to perform addition & subtraction Results of operations are read from the location and number of beads

subtractions William Schickard (1623) 4 Function mechanical calculator Combined

25 History of Computing Mechanical Computers Napier Bones (1617) Invented in Persia Table that reduces multiplication and division to a series of additions and subtractions William Schickard (1623) 4 Function mechanical calculator Combined Napier s Bones, for multiplication and division, with a toothedwheel system to add and subtract.

26 History of Computing Mechanical Computers Pascal s Calculator (1642) Adding machine Accountancy/Taxes Leibniz s Step Reckoner (1674) Full Four Function Calculator

pattern Luddites - Ned Lud and followers; opposed the automation of weaving

27 History of Computing Mechanical Computers Joseph Marie Jacquard (1801) Programmable weaving loom Mechanical Memory punch cards to control weaving pattern Luddites - Ned Lud and followers; opposed the automation of weaving Image of Jacquard woven in silk with a Jacquard Loom; required 24,000 punch cards (1839)

History of Computing Mechanical Computers Charles Babbage (1792-1871) Automate computation for

Projects Difference Engine - Mechanical computer used to create mathematical tables Analytical

28 History of Computing Mechanical Computers Charles Babbage ( ) Automate computation for the purpose of making more accurate mathematical tables for navigation and artillery Two Projects Difference Engine - Mechanical computer used to create mathematical tables Analytical Engine - First programmable computer with separate memory and processing units and punched-card input

29 History of Computing

History of Computing Mechanical Computers Charles Babbage (1792-1871) Neither project was built in his lifetime

30 History of Computing Mechanical Computers Charles Babbage ( ) Neither project was built in his lifetime Difference Engine No. 2 was finally constructed in 1991 by London Science Museum; it worked perfectly. Difference Engine demo

31 History of Computing Mechanical Computers Augusta Ada Byron ( ) Mathematician Developed programming for the Analytical Engine First Computer Scientist Bernoulli number algorithm - Ada Lovelace (1843)

History of Computing Electro-Mechanical Differential Analyzer (1931) Vanevear Bush (1890-1974) A room with a complicated array of gears and shafts driven by electric motors.

32 History of Computing Electro-Mechanical Differential Analyzer (1931) Vanevear Bush ( ) A room with a complicated array of gears and shafts driven by electric motors. Z1 (1935) & Z2 (1939) Konrad Zuse ( ) Binary electrically driven mechanical calculator with limited programmability, reading instructions from punched tape Z2 used electro-mechanical relay switches

vacuum-tube machine (18,000 tubes); weighed 30 tons

33 History of Computing Electronic Computers ENIAC (1945) Electronic Numerical Integrator and Computer Giant vacuum-tube machine (18,000 tubes); weighed 30 tons Developed by John Mauchly ( ) and J. Presper Eckert ( )

rewiring for each particular application; difficult operation Colossus (1943)

34 History of Computing Electronic Computers ENIAC (1945) First* fully programmable electronic computer; not just an electronic calculator Programming required rewiring for each particular application; difficult operation Colossus (1943) British Bletchley Park Used to break Nazi Lorenz Code (Enigma Machine) ENIAC Newsreel Colossus Mk II

35 History of Computing Electronic Computers Development of electronic computers takes place in distinct technological leaps 4 Computer Generations Each generation defined by specific tech innovations Generations are a convenience of history; they are not exact but have some overlap

36 History of Computing First Generation s I/O = punch cards & printer Processor = Vacuum tubes Stored Program Concept Computer program is stored in computer memory Reprogram the machine without rewiring it Manchester Mk I (1948)

37 History of Computing First Generation s Programming Machine Language Binary Assembler Language High-Level Language COLBAL FORTRAN

38 History of Computing First Generation s Programming Grace Hopper ( ) Invent Compiler

39 History of Computing First Generation - Memory Serial Memory RAM Random Access Memory Williams-Kilburn Tubes Mercury Delay Lines Magnetic Core Memory Magnetic Drum

40 History of Computing First Generation s UNIVAC (1951) Eckert-Mauchly Division of Remington Rand Inc. Used by US Census Bureau Predicts Eisenhower s election in 1952

41 History of Computing First Generation s IBM 701 (1953) IBM 650 (1955)

42 History of Computing Second Generation s I/O = Tape & Printer/CRT Monitor Processor = transistors Memory = Magnetic Core Time Sharing

43 History of Computing Second Generation s Time Sharing A number of users at different terminals simultaneously use a single computer for different purposes. Mainframe Computer Terminal

History of Computing Second Generation - 1960s Time Sharing CMC Chat

44 History of Computing Second Generation s Time Sharing CMC Chat Synchronous interaction Asynchronous interaction Bulletin Board Broadcast interaction

History of Computing Second Generation - 1960s Computer Standards

45 History of Computing Second Generation s Computer Standards ASCII = American Standard Code for Information Interchange (1963)

History of Computing Second Generation - 1960s IBM 1401 & 1620 (1958) Fully transistorized Computer for business

46 History of Computing Second Generation s IBM 1401 & 1620 (1958) Fully transistorized Computer for business and scientific research IBM System/360 (1964) Compatible computer Large instruction set Business or Scientific use

47 History of Computing Third Generation - mid 1960s to mid 1970s I/O = Tape/Disk & CRT Monitor Processor = Integrated Circuit Memory = Integrated Circuit Computer Networking Standards

48 History of Computing Third Generation Integrated Circuit Many transistors and circuits integrated on a chip of silicon Invented by Jack St. Clair Kirby and Robert Noyce. First Integrated Circuit Less expensive to manufacture and more efficient than comparable systems comprised of transistors ENIAC on an IC chip

49 History of Computing Third Generation Networking Standards WAN standards (1968) ARPANET Vinton Cerf LAN standards Ethernet (1973) Bob Metcalfe Internetworking Protocols (TCP/IP) (1973)

Metcalfe Law (1973) Bob Metcalfe, inventor of Ethernet LAN N = C 2 - Value of a

50 History of Computing Third Generation Moores Law (1965) Gordon Moore, CEO of Intel Predicted that every 2 years the number of transistors on a chip of silicon doubles Metcalfe Law (1973) Bob Metcalfe, inventor of Ethernet LAN N = C 2 - Value of a computer network (N) is equal to the square of the number of computers (C) connected to it.

51 History of Computing Third Generation DEC s PDP-8 (1965) First commercially available minicomputer IBM and other large corporations did not perceive any market for minicomputers Left development to smaller companies DEC

History of Computing Fourth Generation - 1975+ I/O = Disk, Keyboard & Monitor Processor = Microprocessor Ted Hoff of

52 History of Computing Fourth Generation I/O = Disk, Keyboard & Monitor Processor = Microprocessor Ted Hoff of Intel transistor on one IC Computer on a Chip Memory = IC RAM Personal Computer Intel st Commercial Microprocessor

53 History of Computing Fourth Generation MITS Altair (1975) Sold as a DIY kit Intel 8080 Processor Apple I (1976) $ DIY Project

History of Computing Fourth Generation - 1975+ Apple II (1979)

appliance Full-fledged microcomputer with I/O devices and disk

54 History of Computing Fourth Generation Apple II (1979) Motorola 6502 Processor Conceived of as a personal information appliance Full-fledged microcomputer with I/O devices and disk storage IBM PC (1981) Intel 8088 Processor MS-DOS Operating System Compatible Computer

55 History of Computing Fourth Generation User-Interface Command-line Interface IBM PC/MS-DOS Apple II/Apple OS Graphical User Interface (GUI) Macintosh Windows

56 History of Computing Fourth Generation - GUI Alto - Xerox (1971) Mouse Driven GUI LAN networking Xerox did not commercialize the technology Did not see a market for such a computer Showed it to Steve Jobs in 1979 Alto Demo

57 History of Computing Fourth Generation - GUI Macintosh (1984) First commercially available GUI PC Exploited all the elements of the Xerox Alto Catapulted Apple to the forefront of PC development

58 History of Computing Fourth Generation - GUI Microsoft Windows (1990) GUI for Intel based (IBM compatible) machines Apple sued Microsoft for infringement of copyright over the GUI; Microsoft won Proliferation of MS Windows

59 History of Computing Fourth Generation - GUI Linux (1994) Linus Torvalds Open source operating system based on UNIX Not a commercial product but a community supported open source project

60 History of Computing Fifth Generation? Technologically speaking we are still in the fourth generation Microprocessor and Moores Law At some point (10-20 years) we will reach a physical barrier to the number of transistors that can be placed on a single chip of silicon The next generation is not yet defined

61 History of Computing Fifth Generation? Quantum & Molecular Computers

62 History of Computing

64 Summary Inventor Eckert & Mauchly Babbage Zuse Hopper

65 Summary Size / Weight Reliability Operating Speed Economics / Cost

66 Summary Next-Gen Computers

67 Computer Networks

68 Computer Networks Time Shared Mainframe Computer Network Computer Mainframe Computer Computer Terminal Computer

69 Computer Networks Components Physical media Transmission media Switches/Routers Standards and Protocols Common language for sharing information

70 Computer Networks Transmission Media Twisted Pair/Copper wire Standard 1 Kbps Cat Mbps Cat-5e/6 1 Gbps Coaxial cable 10 Mbps Fiber optic 10 Gbps Wireless 80 Mbps

71 Computer Networks Switching Determines how information moves through transmission media Two types Circuit Switching Packet Switching Circuit Switching Packet Switching

72 Computer Networks Circuit Switching Switch

73 Computer Networks Circuit Switching Switch

74 Computer Networks Circuit Switching Switch

75 Computer Networks Packet Switching Routers

76 Computer Networks Packet Switching

77 Computer Networks Packet Switching

78 Computer Networks Packet Switching

79 Computer Networks Circuit Switching Packet Switching Phyical end-to-end connection Good for real-time voice and video communications Slower through-put & less reliable Connectionless network Good for data communications Faster through-put and more reliable Latency & congestion problems

80 Computer Networks LAN WAN 2 types of computer networks

81 Computer Networks Internet Global WAN

82 Internet History J. C. R. Licklider Proposed idea of a galactic network (1962) Network through which any computer could directly access any other and exchange data

Commissioned RAND Corporation to study the problem (1962) Task: Design a

83 Internet History U.S. DOD concerned about the vulnerability of computer networks for defense Commissioned RAND Corporation to study the problem (1962) Task: Design a computer network that could survive a nuclear attack by the USSR Conclusion: Packet Switched network was the way to go (1964)

84 History of the Internet History ARPANET DARPA - Defense Advanced Research Projects Agency Specify an experimental packet switched network (1968) ARPANET on-line Sept. 1969

85 History of the Internet ARPANET Began with 4 nodes UCLA Stanford Research Institute UCSB University of Utah Connect Universities and research centers doing DOD research

86 History of the Internet Expansion of ARPANET Originally ARPANET was limited to the military and DOD researchers In 1986 ARPANET technology is used by National Science Foundation to create another network - NSFNET Whereas ARPANET was used primarily by DOD research facilities, NSFNET interconnected other educational institutions and government offices

87 History of the Internet

88 History of the Internet Expansion of ARPANET 1991 ARPANET is split into MILNET and Internet MILNET = military network for DOD Internet = public network; administered by NSF Privatization of Internet 1993 NSF turns over basic administrative functions to InterNIC, a private corporation 1995 NSFNET is decommissioned and all network traffic is moved to the very-high-speed Backbone Network Service (vbns) 1995 with the decommissioning of NSFNET, gov t subsidies for the network are removed and the Net is open to commercial traffic (e-commerce)

89 History of the Internet Currently The Internet is a global computer network; It is not one network but a network of networks. Hence the name Inter-net (a network between networks). Although originally administered and funded by US gov't, the current Internet has been almost completely privatized Irony: a technology that was to be used for the defense of the US is now a system employed for international cooperation and communication

90 Computer Networks Protocol Standards or rules that enable networkconnected devices to communicate with each other. These may be implemented by hardward, software, or a combination of both

91 Internet Protocols Protocols for the Internet NCP - Network Control Protocol; initial protocol for ARPANET (1971) TCP/IP - Transmission Control Protocol and Internet Protocol Introduced in Bob Kahn & Vinton Cerf Accepted by ARPANET as the standard in 1982 Current protocol suite running on the Internet

92 Internet Protocols Internet Protocol Stack

93 Internet Protocols Physical Media - Wires and cables - Electrical Signals

94 Internet Protocols Internet Protocol (IP) - Address system for routing data packets to their destination - Ensure that a data packet is sent to the right place - IP number:

95 Internet Protocols Transport Control Protocol (TCP) - Divides message into packets to be managed by IP - Reassembles packets back into the complete message at the other end

96 Internet Protocols Application Layer - Telnet - File Transfer Protocol - - World Wide Web

97 Internet Applications Telnet Introduced in 1972 (RFC-318) Permit access of computer system from a remote location Telecomputing

98 Internet Applications FTP - File Transfer Protocol Introduced in 1973 (RFC-454) Permit the transfer of files from one system to another Download files from the Internet

Internet Applications E-mail Ray Tomlinson

v=xhxk3wzemr4 1971 - First Email message sent

99 Internet Applications Ray Tomlinson ( ) First message sent accounts for 75% of all traffic on ARPANET

100 Internet Applications World Wide Web Invented by Tim Berners-Lee at CERN (Switzerland) Proposed in 1989 Organize information for Physicists Complex relational data base of documents Operational in mid-1990s Media Convergence Hypertext Multimedia

101 Summary Computer Networks - Transmission media - Switching (circuit or packet) - Architecture LAN & WAN - Internet Protocols TCP/IP - Internet Applications

102 Preview Book Talk Robot Rights 6 February pm Founders Memorial Library

103 Preview Next week (11 February) Conference Utrecht, NL No class meeting Work on Project Proposal

Preview Next Class = 18 February Project Proposals

Licklider The Computer as Communications Device James

Livingston Critical Debates in Internet Studies Susan

104 Preview Next Class = 18 February Project Proposals Due Coding Exercise Topic: CMC (presentation) J.C.R. Licklider The Computer as Communications Device James Carey A Cultural Approach to Communication Sonia Livingston Critical Debates in Internet Studies Susan Herring Slouching Toward the Ordinary: Current Trends in CMC

Computers in Engineering COMP 208. A Brief History. Mechanical Calculators. A Historic Perspective Michael A. Hawker

Computers in Engineering COMP 208 A Historic Perspective Michael A. Hawker Sept 4th, 2007 Computers in Engineering 1 A Brief History Abacus considered first mechanical computing device Used beads and rods