1. Introduction to Computer Science Computer History Mr. Oei ICS 2O1

2. What is a computer? System unit (tower) Monitor CD-ROM / DVD-ROM Drive USB slots

3. com·put·er 1) A person who makes calculations, esp. with a calculating machine or 2) A machine that calculates! Before we had the modern digital machines we possess today, computers started off as Analog Devices

4. Analog Computers What does analog mean? Analog: Relating to, or using, information represented by an ever-changing physical quantity

5. What were the first computational devices invented? The first devices we had were based on our hands and fingers!

6. The Salamis Tablet 500 BC Ancient Babylonian counting board!

7. 1300 AD In more recent times, we’re used to seeing the evolved version of the counting board… The Chinese abacus! http://www.alcula.com/suanpan.php http://www.alcula.com/soroban.php crazy japanese abacus students http://webhome.idirect.com/~totton/abacus/pages.htm The Japanese abacus! (Soroban)

8. Mechanical Counting Machines 1642 pascaline short vid The Pascalineis a mechanical calculating deviceinvented by the French philosopher and mathematician Blaise Pascal in 1642.

9. Mechanical Counting Machines 1673 The Leibniz Wheelwas invented by the famous mathematician Leibniz in 1673. ( + , - , * , / )

10. Mechanical Counting Machines 1801 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.

11. Mechanical Counting Machines Babbage’s Difference Engines were calculating machines made by Charles Babbage to produce tables of numbers that would be used by ship’s navigators. 1822

13. weighed fifteen tons (13,600 kg),

14. 8 ft (2.4 m) tallHow big was it??

15. Charles Babbage This device had mechanical problems similar to those that Pascal and Leibniz had, and was not completed until 1991 by the London Science Museum. Babbage did not give up –went on to make a more general purpose, and complex machine…

17. Electrical Counting Machines & Herman Hollerith 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 1) Machine readable media (through the use of punched cards) 2) A tabulator to process these punched cards 3) Key punch machine to make the cards 1888

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:International Business Machines IBM 1888

20. Electrical Counting Machines 1943 51 feet long and weighed over 5 tons 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. Was also used to control weapons during the war!

21. A summary of analog computers Truly parallel - Therefore can perform multiple calculations at the same time Strength in calculating mathematical, physical and technical problems through the interaction of continuously varying (or dynamic) physical quantities or measures Used mechanical, electrical, and hydraulic means to perform calculations ex. speedometers, simulating weather patterns, analyzing hydraulic networks

22. Electronic Counting Machines By 1950, IBM had become ubiquitous in industry and government! 1946 Then came the ENIAC !! The first US-built all-electronic computer built to perform ballistics calculations. (Away from IBM)

23. Electronic Counting Machines * It was 1000X faster than Mark I, but drew a lot of power …even dimmed the lights of Philadelphia when switched on!! * Mark I: 5 Additions / sec. * ENIAC: 5,000 Additions / sec. * ENIAC was made of 18,000 vacuum tubes. 1946

24. Electronic Counting Machines ENIAC’s Problems: 1- short life of vacuum tubes 2- It runs a single program, which means rewiring by a group of technicians is needed to change the program!!! Solution: the same group of researchers worked on another version of ENIAC that stored programs on punched cards 1946

25. Transitioning into the era of modern computing

26. Computers and society In what two ways/areas did computers significantly impact World War II and how did computers help? www.alcula.com/suanpan.php www.alcula.com/soroban.php