History 329/SI 311/RCSSCI 360 Computers and the Internet: A global history
The ARPANET
Today
} Two frameworks for the history of computers & networks } The computer utility: mainframes as power plants } ARPANET and the networking environment of the 1960s } Vietnam } Exam logistics & review Global history: so far…
Two frameworks for thinking about the history of computers and networks
4 2/11/16 Framework 1: technological trajectories
} Related, but different: } Hardware } Software } applications } Networking
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Framework 1: technological trajectories Hardware
} Tubes > transistors > integrated circuits > microprocessors } Moore’s Law: the number of transistors on an integrated circuit doubles every 18 months to 2 years } Mainframes > minicomputers > personal computers > PDAs > smartphones } Bell’s Law:
6 2/11/16 Moore’s law: transistors per microprocessor 7
Gordon Bell’s “Law of Computer Classes”
} Technology enables two evolutionary paths: 1. constant performance, decreasing cost 2. constant price, increasing performance
mainframes
minicomputers workstations
Log price PCs PDAs smartphones Time etc.
8 Framework 1: technological trajectories Software
} Languages: machine > assembly > higher level > structured > object oriented } Applications: custom > programming services > packaged software > cloud } Brooks’ Law: adding manpower to a late software project makes it later
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Framework 1: technological trajectories
} Networking } Timesharing > homogeneous > heterogeneous > webs (internets) } Metcalfe’s Law: the value of a telecommunications network is proportional to the square of the number of connected user
10 2/11/16 Framework 2: Functional evolution
} Calculation —> symbol processing (information) } Control } Communication
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Framework 2: Functional evolution The 1940s: Computers as Calculators
} Primarily for science } Nuclear weapons } Code-breaking } Meteorology } Extremely expensive } Unreliable, complex, power-hungry } H. Aiken, 1947: “there will never be enough problems, enough work, for more than one or two of these [digital] computers”
12 2/11/16 Framework 2: Functional evolution The 1950s: Computers for Control
} SAGE } Radar-based nuclear early warning } Automatic guided interception } Centralized computer control } Initially resisted by Air Force, others
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Framework 2: Functional evolution The 1960s: Computers for Communication
} “Computer utilities” } Proprietary time-sharing networks } ARPANET } Initial motives } Communication among ARPA researchers } Survivable nuclear command/control } Later: email, newsgroups dominated } From special-purpose (sharing programs and data) to general medium (text)
14 2/11/16 The computer utility: mainframes as power plants
Grosch’s Law (1953)
} “The performance of a computer varies as the square of its price” } Ergo, a $1 million computer is 25 times as fast/powerful/useful as a $200,000 computer } Bigger is better: analogy to electric power plants } Extensively studied in 1960s-70s } Encouraged “computer utility” idea (~1965-70) } Centralization is better
Herb Grosch The computer utility Computation, like electricity and unlike oil, is not stored. Since its production is concurrent with its consumption, production capacity must provide for peak loads, and the cost of equipment per dollar of revenue can soar. The high cost of capital equipment is a major reason why producers of electricity are public utilities instead of unregulated companies. A second reason is the extensive distribution network they require to make their product generally available. This network, once established, is geographically fixed and immovable. Wasteful duplication and proliferation of lines could easily result if there were no public regulation. …an on-line interactive computer service, provided commercially by an information utility, may be as commonplace by 2000 A.D. as the telephone is today — Martin Greenberger (1964)
The future… viewed in 1967 ARPANET and the Networking Environment of the 1960s
20 2/11/16 Baran’s network concept (1961)
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The Advanced Research Projects Agency (ARPA)
} Founded 1958 in response to Sputnik (1957) } “...spawned in an atmosphere that equated basic research with military security” } 1960: space programs to NASA } ARPA mission redefined } Potential relevance to military needs } Saw itself as a kind of NSF within the DoD NSF vs. ARPA as Funding Agents
NSF ARPA • Civilian • Military • Peer review • Director/staff discretion • Rough • Centers of geographical excellence equity • Unclassified • Could classify research research (but usually didn’t) • Published results • No publication requirement (but much published) • 1-3 year grants • Long-term, informal funding arrangements • Broad range of • Small number of research focus areas
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ARPA’s Information Processing Techniques Office (IPTO) } Origins } Concern about System Development Corporation cutbacks } 1961 - command and control research assigned to ARPA } IPTO founded 1962 } Young, aggressive managers } Mandate for large, well-funded projects } Long-term orientation IPTO’s First Director: J. C. R. Licklider
} Psychoacoustician } Worked on SAGE interface } Influenced by John McCarthy } AI, time-sharing } Advocate of “interactive computing”
“Man-computer Symbiosis” (Licklider, 1960)
“The hope is that, in not too many years, human brains and computing machines will be coupled together very tightly, and that the resulting partnership will think as no human being has ever thought and process data in a way not approached by the information-handling machines we know today.”
} Military metaphors } Needs for speed, real-time computing, interactive computing ADVANCED RESEARCH PROJECTS AGENCY
Washington 25, D.C. April 23, 1963
MEMORANDUM FOR: Members and Affiliates of the Intergalactic Computer Network
FROM: J. C. R. Licklider
SUBJECT: Topics for Discussion at the Forthcoming Meeting
First, I apologize humbly for having to postpone the meeting scheduled for 3 May 1963 in Palo Alto. The ARPA Command & Control Research office has just been assigned a new task that must be activated immediately, and I must devote the whole of the coming week to it….
IPTO’s “Centers of Excellence” Strategy
} Budgets: 30-40x larger than most academic laboratories } To “improve the C3I systems required by an increasingly technological military” } MIT } Stanford } Univ. of Michigan } Carnegie-Mellon University } Univ. of California, Berkeley } Univ. of Utah } Stanford Research Institute (SRI) } Systems Development Corp. (SDC) IPTO’s Role in Computer Science
} Main military funder of basic research, 1960s-80s
} Major focus areas } Time-sharing } Computer graphics } Artificial intelligence } Computer networks
IPTO and Time-sharing
} 1967: six of top 12 time-sharing systems ARPA-sponsored } Commercial time-sharing systems } 1967-68: the “computer utility” } By 1969: TYMNET, CYBERNET, Compuserve, others.. } Time-sharing centers } By early 1970s, time-sharing integrated into commercial office systems } Military time-sharing systems widely used in 1970s, based in ARPA IPTO projects A Computer Network Typology } Homogeneous networks (systems) } link similar or identical computers } Heterogenous networks (networks) } link different kinds of computers } Internetworks (webs) } link different networks
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The ARPANET } 1969: ARPANET construction began } BBN Interface Message Processor (IMP) } First node at UCLA } 1971: 15 nodes (23 hosts) } UCLA, SRI, UCSB, U of Utah, BBN, MIT, RAND, SDC, Harvard, Lincoln Lab, Stanford, UIUC, CWRU, CMU, NASA/Ames
34 2/11/16 ARPANET structure
Subnet: a homogeneous network of IMPs, linking heterogeneous hosts
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ARPANET, December 1969
36 2/11/16 ARPANET, December 1970
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ARPANET, March 1972
38 2/11/16 ARPANET, September 1973
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The ARPANET } 1974 } Cerf and Kahn, "A Protocol for Packet Network Internetworking" } BBN opened Telenet } First public packet data service } Serviced 68 cities by 1977 } Still a homogeneous network design } 1975: ARPANET transferred to control of Defense Communications Agency
40 2/11/16 ARPANET, July 1975
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42 2/11/16 Vietnam The Vietnam War (1965-1974)
} Procurements for war reduced military research budget } Mansfield Amendment (1969) } prohibited use of military funding for projects without direct military application — directed at ARPA } IPTO response: } shorter projects } new justifications
Proportion of Federal and Private R&D Funds (all fields), 1945-90
120 100 80 60 40
Percenttotal of 20 0 1945 1955 1965 1975 1980 1985 1990
Federal Private Federal Funding for Math and CS, 1972-86
600 500 400 300 200 100 1982 dollars 0
Millions of constantMillions of 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
DOD DOE/NASA NSF Other
Computers and statistics in Vietnam
} War run from Washington: centralized command/control } Complex communication webs } Battlefield data collection problems } Statistical approach obscured ground realities } High-tech armies vs. peasant guerillas Operation Igloo White
} The McNamara Line } Infiltration Surveillance Center } SAGE-like command-control center
The “Electronic Battlefield” (Gen. Wm. Westmoreland)
} Remote sensors } Remote command and control } Fully integrated calculation, communication, and control } A visionary discourse that has guided military research ever since Exam review
Next time: midterm exam
} In class, February 16 } Covers all materials through today (Feb 11) } Study questions distributed Feb 9 } Identifications (16 study Qs, 8 on exam, choose 5) } Short answers (14 study Qs, 5 on exam, choose 3) } Essay questions (7 study Qs, 3 on exam, choose 2)
Logistics for midterm
} Bring two LARGE-FORMAT blue books to class. Do not write anything in them in advance – not even your name. } Bring pens or pencils } Arrive early if possible } Exam will start at exactly 4:10 } Points are keyed to budgeted time: 1 pt./min, total = 75 points/minutes. } Exam ends promptly at 5:35 PM } I encourage you to study for the exam with other students!
Identifications and short answers
} ENIAC women } Brooks’ Law } differential analyzer } Colossus } IBM Card-Programmed } Social Security } Williams tube Calculator Administration (computing aspects) } magnetic core memory } packet switching } IBM System 360 } Herman Hollerith } microprocessor } EDVAC report } Analytical Engine } Whirlwind } cybernetics } Ada Lovelace } Turing test } UNIVAC } bit } tide predictors } John von Neumann } analog computer } Grace Hopper } Antikythera } ARPANET mechanism } analog-digital } Manchester Mark 1 conversion } microprocessor } shipboard fire control