Scope and History of Computing

1
Scope and History of Computing

• "Scientists build to learn engineers learn to
  build"
• -Fred Brooks

2
Overview

• Scope of Computer Science    
• History of Computing and Computing Machines    
• Branches of Computer Science    
• Careers in Computer Science

3
Scope of Computer Science

• What problems can computers solve?
•  Intractable Traveling Salesman Problem
•  Unsolvable The Halting Problem
•  Solvable Has at least one definite solution

4
Scope of CS continued

• How can computers be used to solve problems?
•           Abstraction as a tool for developing
  solutions
•           Algorithms Step-by-step recipe for
  solution
•           Applying known algorithms to Machines
•           Limitations of the machine

5
History of Computer Science Part I

• Abacus (Ancient)
• Much of the 'computation' is done by humans to
  operate and read the abacus
• More of a Data Storage machine than a
  'calculator
• 2. Mechanical Gear Technology (1600s)
• Pascal's Adding Machine and Leibniz's Arithmetic
  Machine
• Jacquard's Loom Draw Looms used Master Weaver
  and Draw Boy to weave intricate patterns
•           - essentially stored the knowledge
  (patterns) of the Master Weaver in the loom
  itself
•           -storing 'expertise' in a machine
  Automatic Lathe duplicates master woodworker
  patterns
•          
•        

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History of CS Part 2

• 2. Mechanical Gear Technology (continued)
• Extension of Jacquard's punch card idea - use of
  Algorithm
• Babbage Prototype Difference Engine and design
  for Analytical Engine
• Babbage First General Purpose machine that
  stores instructions that can be repeatedly
  executed
• Countess Lovelace's contribution
• Hollerith used punch card idea to speed up U.S.
  census tabulation          
• Hollerith fledgling venture Tabulating Machine
  Company is today's IBM
•   Disadvantage of Gear Technology
• cumbersome gear operations
• expensive!

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History of CS Part 3

• 3. Electromechanical( early 1900s) First
  Generation
• Use current electricity to represent information
• Atanasoff (Iowa State College) physicist needed
  to speed up calculations and minimize drudgery
• Morse code already existed codes information
  electrically
• ABC (Harvard Mark I, Zuse's Z1-Z4)
  single-purpose machine to solve system of Linear
  Equations
• Advantage electrons are light and tiny and can
  be shoved around fast

8
History of CS Part 4

• 4. Electronics (mid 1900s) Second Generation
• 1930s Warfare demanded complex sets of
  information to be handled speedily and accurately
  
• Military research British Colossus and American
  ENIAC
• Colossus for code-breaking ENIAC for ballistic
  firing tables for artillery - still mostly
  electromechanical...
•   ...Until Bell Labs made the first transistor in
  1947, which revolutionized computers - much
  smaller and compact and more efficient without
  the large clunky parts

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History of CS Part 5

• 5. Modern Computers (1970 to present)
• End of 60's Airline reservation automated,
  computers used by most businesses
• Birth of new PLs COBOL, FORTRAN, BASIC, closer
  to human language than machine
• Third Gen Integrated circuits with 1000s of
  transistors
•           by mid-70's hand-held calculator less
  than 0.5 lbs could calculate faster than
  room-sized ENIAC
• Early 1970's birth of the microchip
• Fourth Gen LSI
•           HP, IBM ignore "microchip" mid
  1970's Apple Computer Inc., launched
• More on RISC, CISC in Architecture and Hardware
  lectures

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Branches of CS I

• I. Theory of Computing
•     
• The Turing Machine imaginary device invented by
  Alan Turing even before there were computers to
  solve problems
• Nothing to do with any particular technology
  just a model for clear box computation
• Church-Turing thesis Theoretically show that
  there are some problems that cannot be solved by
  Turing Machines, therefore, probably cannot be
  solved by any programs for any computer

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Branches of CS II

• II. Computer Architecture
•     
• An Architect can design a building without
  worrying about such details as whether the window
  is to be made of wood, steel, glass etc.
• A Computer Architect can fit components with
  definite functionality together, leaving the
  Engineers to design and integrate the circuits,
  components into physical form
• CPU and Memory Fetch-Execute cycle Load-Store
  Registers

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Branches of CS III

• III. Artificial Intelligence 1959, coined by
  John McCarthy
•     
• Notion of embodying intelligence in a machine
• Knowledge Processing (as opposed to Information
  processing)
• Simple Problem-Solver Identify a solution state
  use a collection of rules to move closer to this
  solution state than the state you are in now.
• ELIZA Language Processing program - a script
  enables it to play the role ofa neutral
  psychotherapist
• Neural Networks

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Branches of CS IV

• IV. Programming Languages
•     
• What is a program? How can a computer execute a
  program?
• Machine Language Assembly-level, 0 and 1, not
  easy for humans to deal with, possible
  transcription errors
• Design a language specify form of the
  statements, and what each statement should do
• Write an Interpreter or Compiler that takes our
  language and produces an object code in the
  machine's language
• Examples COBOL, Pascal, Prolog, Scheme, C, C,
  Java, Perl, BASIC

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Branches of CS V

• V. Data Modeling, Storage
•     
• Data Structure
• Data Format, Storage Format
• Data Encryption
• (R) DBMS

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Branches of CS VI

• VI. Software Engineering
•     
• Analysis
• Design
• Implementation
• Testing
• Each step may require any of the earlier steps to
  be repeated and refined.

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Careers in Computer Science

• 1. Application Programmer
•     
• 2. System Programmer
•     
• 3. Software Engineer
•     
• 4. Systems Analyst, Engineer
•          
• 5. Theorist algorithms
•     

• 6. Architecture, Hardware
•     
• 7. Database Programmer
•     
• 8. Database Administrator
•     
• 9. Web master, Web developer
•     
• 10. Computer Operator

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Social Impact of Computer Science

• Group Task Trends in Technological Advancement
  and its Social Impacts
•  1. List 5 computer-based-technologies that
  exists today, ubiquitously, that didn't exist 20
  years ago
•    For example,
• bar-coded self check-outs at supermarkets
• computer-controlled traffic lights
• robotics in Space Station building
• 2. List 5 that were commonly used 20 years ago
  that are obsolete now.
• 3. Propose 5 new technological advancements that
  you envision will be in use 10 years from now
• 4. List 5 current technological features of daily
  life that you envision will be obsolete 10 years
  from now
• One spokesperson per group will present their
  group's answers for the above 4 in class. (Date
  for the presentation will be announced in class
  later.)

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Role of Abstraction in Computer Science

• Abstraction refers to the distinction between
  the external properties of an entity and the
  details of the entity's internal composition
• -J.BrookshearMeaning... abstract out the
  general characteristics of a set of objects to
  better understand them
•      Used in everyday life to get an "overview"
  without being bogged down by details, until
  needed
•     
• For Example
• Sheela visits the zoo for the first time and sees
  a deer. "Neat Dog!", she cries.
• Sheela has seen no other 4-legged creature other
  than her pet dog, it turns out.
• So, she managed to abstract the 4-leggedness as a
  general property of all creatures that was like
  her own pet, and gave it the generic name "dog".
      

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Abstraction Exercise

• Exercise Abstract the components of a typical
  Personal Computer.
• Exercise Identify various general properties
  (components) of typical small city.
• Shopping center
• Library
• Residential areas
• Community center
• Public Transportation System
• Recreational centers, Parks
•      Software Engineering primarily relies on
  abstraction for the design, adding details and
  refining the model as we get down to specifics of
  the software.
•      Object Oriented Design, Programming (OOP)
  relies on such abstract modeling to create the
  Object Model even before a single line of
  programming code is written.