Introduction to Computers

1. Introduction to Computers Lecture 1 Prepared by Natalie Rose

2. Web Page and Book List • Main Course Web Page is at: http://nnrose.weebly.com • Recommended Text Shelly Cashman:Discovering Computer 2011 Prepared by Natalie Rose

3. Data vs. Information Data: Representation of a fact or idea Information: Organized, meaningful data Prepared by Natalie Rose 3

4. Data, Information • Data vs. Information • Data (PLURAL) - SINGULAR IS DATUM • A “given” or fact: a number, a statement, or a picture • The raw facts in the production of information • Information • Data that have meaning within a context • Raw data or data that have been manipulated Prepared by Natalie Rose

5. Computers Are Data Processing Devices Computer’s four major functions: Gathers data (users input data) Processes data into information Outputs data or information Stores data and information Prepared by Natalie Rose 5

6. What Computers Do • Basic Components of a Computer • Input devices • Keyboards and pointing devices (mouse) • Output devices • Display or video monitor • Printer • Speakers • Central Processing Unit (CPU) Prepared by Natalie Rose

7. What Computers Do • Basic Components of a Computer • Memory and storage devices • Primary storage: RAM (Random Access Memory) • Secondary storage: Storage devices that serve aslong-term repositories for data: • Hard disk drives • Recordable CD and DVD drives • Tape drives Prepared by Natalie Rose

8. Memory Central Processing Unit (CPU) ControlUnit ArithmeticLogic Unit Output Input Registers Components of a Computer System Prepared by Natalie Rose

9. Bits and Bytes: The Language of Computers Bit Binary digit 0 or 1 Byte Eight bits Each letter, number, and character = a string of eight 0s and 1s Prepared by Natalie Rose 9

10. A Bit About Bits Bits, Bytes, and Buzzwords Bit-related terminology • Byte • Kilobyte (KB) • Megabytes (MB) • Gigabytes (GB) • Terabytes (TB) = 8 bits = 1 Thousand Bytes = 1 Million Bytes = 1 Billion Bytes = 1 Trillion Bytes Prepared by Natalie Rose

11. Chapter 2 Summary Questions What devices do you use to get data into the computer? Prepared by Natalie Rose 11

12. Chapter 2 Summary Questions What devices do you use to get information out of the computer? Prepared by Natalie Rose 12

13. Chapter 2 Summary Questions What’s on the front of your system unit? Prepared by Natalie Rose 13

14. Chapter 2 Summary Questions What’s on the back of your system unit? Prepared by Natalie Rose 14

15. History of Computers • Mechanical and electromechanical devices preceded the electronic computer. • Charles Babbage (1830’s): the analytical engine, and Augusta Ada Byron, the first programmer. Prepared by Natalie Rose

16. Charles Babbage’s Analytical Engine Prepared by Natalie Rose

17. Electro-Mechanical Devices • (1890’s): electrical tabulating machine, and foundation of IBM (1924). • Aiken’s Mark 1. (1944) based on Babbage’s original design - built at IBM labs, electro-mechanical, weighed 5 tons. • Admiral Grace Hopper worked as programmer on this computer, and coined in the term 'bug' for a computer fault. Prepared by Natalie Rose

18. Electronic Computers • To increase speed and reliability, the mechanical components of these early devices were replaced by electronic equivalents. • These fully electronic devices became known as the of computers. • Successive generations of electronic computers have greater speed, smaller size, larger memory. Prepared by Natalie Rose

19. First Generation • 1st Generation: (1945-1956). • Vacuum Tubes used as switching and storage components. • Atanasoff & Berry (1939) first electronic digital computer. • Turing (1943) Colossus machine built to decode encrypted messages. (*Turing Test) • ENIAC (1946) first general purpose computer. (decimal not binary machine) • UNIVAC (1951) first commercial computer - commissioned for 1950 US census. Prepared by Natalie Rose

20. First Generation • Problems with vacuum tube machines: • severe overheating, • manual setting of each instruction, • use of machine language only. • Magnetic core used for memory, punched cards and later magnetic tape for secondary storage. • Computers used for scientific and government purposes. Prepared by Natalie Rose

21. First Generation • In 1945 John von Neumann proposed the ‘stored program concept’, with memory to store both data and instructions. • Loading a new program into memory then allows a new function for the computer. • In Von Neumann’s basic design, the program is executed in a sequential manner. • While still the model for most conventional computers, parallel processing has recently challenged this aspect of the traditional computing device Prepared by Natalie Rose

22. Second Generation 2nd Generation: (1956-1963). Transistors. • Transistors replaced vacuum tubes. smaller, faster, more reliable, and use less energy • Development of symbolic languagesSimpler programming -eg ADD instead of 00000101, high level languages Fortran and Cobol. • Provision of system software (OS). • Computers used by military, government and big business. • Problems: 100s or 1000s of transistors required for powerful machines, expensive and cumbersome • This problem was solved by the invention of the integrated circuit Prepared by Natalie Rose

23. Third Generation 3rd generation: (1964-1971). Integrated Circuits. • Complete electronic circuit on single silicon chip, smaller than single transistor. • 1000’s of components on one chip.(SSI to MSI) • cheap, fast and reliable. • used by small business Prepared by Natalie Rose

24. Fourth Generation 4th generation: (1975-1984). Microprocessors • Microprocessor contains ALL elements of CPU on one chip (Intel’s 4004, 1971). • Progressively greater integration (from LSI to VLSI) - 100,000’s to millions of components per chip. • Increasing • complexity of instruction sets, • no of bits handled at once, • amount of memory addressed. • Advent of personal computers and other microprocessor controlled devices. Prepared by Natalie Rose

25. Fifth Generation • 5th Generation:Ultra Large Scale Integrated Circuits (ULSI): over 1 million Transistors per Integrated Circuit or Chip Prepared by Natalie Rose

26. Performance Enhancements Computer performance has been greatly enhanced by the following : • Faster clock speed • Overlapping & Parallel instruction processing • Wider, faster data paths (Buses) • Faster disk access • Bigger and Faster memory, including advanced cache technology • Optimised software Prepared by Natalie Rose