Introduction to computer science


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Introduction to computer science

  1. 1. Introduction to Computer Science<br />Computer History<br />Mr. Oei<br />ICS 2O1<br />
  2. 2. What is a computer?<br />System unit (tower)<br />Monitor<br />CD-ROM / <br />DVD-ROM Drive<br />USB slots<br />
  3. 3. com·put·er<br />1) A person who makes calculations, esp. with a calculating machine<br />or<br />2) A machine that calculates!<br />Before we had the modern digital machines we possess today, computers started off as <br />Analog Devices<br />
  4. 4. Analog Computers<br />What does analog mean?<br />Analog:<br />Relating to, or using, information represented by an ever-changing physical quantity<br />
  5. 5. What were the first computational devices invented?<br />The first devices we had were based on our hands and fingers! <br />
  6. 6. The Salamis Tablet<br />500 BC<br />Ancient Babylonian counting board!<br />
  7. 7. 1300 AD<br />In more recent times, we’re used to seeing the evolved version of the counting board…<br />The Chinese abacus!<br /><br /><br />crazy japanese abacus students<br /><br />The Japanese abacus! (Soroban)<br />
  8. 8. Mechanical Counting Machines<br />1642<br />pascaline short vid<br />The Pascalineis a mechanical calculating deviceinvented by the French philosopher and mathematician Blaise Pascal in 1642. <br />
  9. 9. Mechanical Counting Machines<br />1673<br />The Leibniz Wheelwas invented by the famous mathematician Leibniz in 1673.<br /> ( + , - , * , / )<br />
  10. 10. Mechanical Counting Machines<br />1801<br />Punched Cards were used by the French weaver Joseph Jacquard in 1810. The cards carried weaving instructions for the looms, later this idea offered a great use for storing info.<br />
  11. 11. Mechanical Counting Machines<br />Babbage’s Difference Engines were calculating machines made by Charles Babbage to produce tables of numbers that would be used by ship’s navigators.<br />1822<br />
  12. 12. Charles Babbage<br />Difference engine was among the FIRST mechanical computers<br />Babbage was tired of having humans “compute” calculations… and make mistakes<br />Although it was extremely big, the basic architecture of it was very similar to a modern computer!<br />composed of around: <br /><ul><li>25,000 parts,
  13. 13. weighed fifteen tons (13,600 kg),
  14. 14. 8 ft (2.4 m) tall</li></ul>How big was it??<br />
  15. 15. Charles Babbage<br /> This device had mechanical problems similar to those that Pascal and Leibniz had, and was not completed until 1991 by the London Science Museum. <br />Babbage did not give up –went on to make a more general purpose, and complex machine…<br />
  16. 16. The Analytical Engine<br /><ul><li>Combined Jaquard’s punch-card technology in order to pre-program commands</li></ul>1847-1849<br />babbage difference engine #2<br />demo of difference engine<br />Employs many of the features that modern day computers possess!<br />
  17. 17. Electrical Counting Machines & Herman Hollerith<br /> The US census of the 1880 took 9 years to compile and led to inaccurate figures. To solve the problem, Herman Hollerith invented three things<br />1) Machine readable media (through the use of punched cards)<br />2) A tabulator to process these punched cards<br />3) Key punch machine to make the cards <br />1888<br />
  18. 18. IBM<br /><ul><li>Hollerith’s machine was immensely successful. The general count of the population, then 63 million, took only 6 weeks to calculate!
  19. 19. Based on the success of his invention, Herman Hollerith and some friends formed a company that sold his invention all over the world. The company eventually became known as:</li></ul>International Business Machines <br />IBM<br />1888<br />
  20. 20. Electrical Counting Machines<br />1943<br />51 feet long and weighed over 5 tons<br />MARK I was built by a team from IBM and Harvard University. Mark I used mechanical telephone switches to store information. It accepted data on punched cards, processed and then output the new data.<br />Was also used to control weapons during the war!<br />
  21. 21. A summary of analog computers<br />Truly parallel - Therefore can perform multiple calculations at the same time<br />Strength in calculating mathematical, physical and technical problems through the interaction of continuously varying (or dynamic) physical quantities or measures<br />Used mechanical, electrical, and hydraulic means to perform calculations<br />ex. speedometers, simulating weather patterns, analyzing hydraulic networks<br />
  22. 22. Electronic Counting Machines<br />By 1950, IBM had become ubiquitous in industry and government!<br />1946<br />Then came<br />the ENIAC !!<br />The first US-built all-electronic computer built to perform ballistics calculations. (Away from IBM)<br />
  23. 23. Electronic Counting Machines<br />* It was 1000X faster than Mark I, but drew a lot of power …even dimmed the lights of Philadelphia when switched on!!<br />* Mark I: 5 Additions / sec.<br />* ENIAC: 5,000 Additions / sec.<br />* ENIAC was made of 18,000 vacuum tubes.<br />1946<br />
  24. 24. Electronic Counting Machines<br />ENIAC’s Problems:<br />1- short life of vacuum tubes<br />2- It runs a single program, which means rewiring by a group of technicians is needed to change the program!!!<br />Solution: the same group of researchers worked on another version of ENIAC that stored programs on punched cards<br />1946<br />
  25. 25. Transitioning into the era of modern computing<br />
  26. 26. Computers and society<br />In what two ways/areas did computers significantly impact World War II and how did computers help?<br /><br /><br />