Lecture1 100412095202-phpapp02


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Lecture1 100412095202-phpapp02

  1. 1. Introduction and Overview <ul><li>Questions answered in this lecture: </li></ul><ul><ul><li>What is an operating system? </li></ul></ul><ul><ul><li>History of Linux ? </li></ul></ul><ul><ul><li>Comparison between Linux & Windows? </li></ul></ul>University of Education Linux Operating Systems Muhammad Amer Irshad
  2. 2. Operating System
  3. 3. What is an Operating System? <ul><li>OS: Everything in system that isn’t an application or hardware </li></ul><ul><li>OS: Software that converts hardware into a useful form for applications </li></ul>Not easy to define precisely… Compilers databases word processors CPU memory I/O devices Users Hardware Operating System Applications
  4. 4. First commercial systems <ul><li>1950s Hardware </li></ul><ul><ul><li>expensive, and slow </li></ul></ul><ul><ul><li>Input/Output: Punch cards and line printers </li></ul></ul><ul><li>Goal of OS </li></ul><ul><ul><li>Get the hardware working </li></ul></ul><ul><ul><li>Single operator/programmer/user runs and debugs interactively </li></ul></ul>
  5. 5. Current Systems <ul><li>Conclusion: OS changes due to both hardware and users </li></ul><ul><li>Current trends </li></ul><ul><ul><li>Multiprocessors </li></ul></ul><ul><ul><li>Networked systems </li></ul></ul><ul><ul><li>Virtual machines </li></ul></ul><ul><li>OS code base is large </li></ul><ul><ul><li>Millions of lines of code </li></ul></ul><ul><ul><li>1000 person-years of work </li></ul></ul><ul><li>Code is complex and poorly understood </li></ul><ul><ul><li>System will always contain bugs </li></ul></ul><ul><ul><li>Behavior is hard to predict, tuning is done by guessing </li></ul></ul>
  6. 6. A Brief History of
  7. 7. Linux Operating System
  8. 8. Bell Labs
  9. 9. C
  10. 10. Unix Unix was created by Ken Thompson and Dennis Richie on a &quot;spare&quot; DEC PDP-7
  11. 11. Why Unix? <ul><li>To play games faster on company hardware. </li></ul><ul><li>To experiment more with creating a multi-user multi-tasking computer system. </li></ul><ul><ul><li>This didn't happen in Windows until XP. </li></ul></ul>Ken Thompson and Dennis Richie
  12. 12. Every job needs a tool <ul><li>The C programming language was created to be a systems programing language. </li></ul><ul><ul><li>“ C is a... systems implementation language. It was designed ... to provide low-level access to memory, to provide language constructs that map efficiently to machine instructions, and to require minimal run-time support. C was therefore useful for many applications that had formerly been coded in assembly language.” </li></ul></ul><ul><ul><li>C has expanded to be used for general application use. </li></ul></ul><ul><ul><li>Called C because many features came from an early programming language called B. </li></ul></ul>Hello, World!
  13. 13. Early Unix History <ul><li>Work began in 1970 on Unix. </li></ul><ul><ul><li>The name is a pun on Multics (Unics). </li></ul></ul><ul><ul><li>The first application was a word process (1971). </li></ul></ul><ul><li>C was developed in 1972. </li></ul><ul><li>In 1973 Unix was rewritten in C. </li></ul><ul><ul><li>Writing system code in a language was unheard of. </li></ul></ul><ul><ul><li>Allowed for portability. </li></ul></ul>
  14. 14. Unix growth <ul><li>For a modest fee Bell Labs would send you the source code. </li></ul><ul><li>Became popular for universities and students for to us as example code. </li></ul><ul><li>Minix was developed to teach student systems level programming. </li></ul>
  15. 15. GNU Manifesto <ul><li>Richard Stallman started GNU (circa 1985) </li></ul><ul><li>End goal was a free Unix-like system. </li></ul><ul><li>Developed clones of Unix utilities that were often better than the originals. </li></ul><ul><li>The kernel was not developed at this time. </li></ul>
  16. 16. Linus Torvolds <ul><li>Wrote his own Unix-like kernel in 1991. </li></ul><ul><ul><li>To demonstrate his understanding of systems programming. </li></ul></ul><ul><ul><li>Released as open source in 1992. </li></ul></ul><ul><ul><li>Named by his friend/file host. </li></ul></ul>
  17. 17. Tux <ul><li>The Linux Kernel mascot is a penguin named 'Tux'. </li></ul><ul><li>It was chosen by the Linux Benevolent Dictator for Life. </li></ul>
  18. 18. Choosing a mascot <ul><li>In early 1996 people were discussing the need to a logo for Linux. </li></ul><ul><li>Several ideas were suggested. </li></ul>
  19. 19. Why A Penguin? <ul><li>“ Ok, short version: </li></ul><ul><li>“ I've always liked penguins, and when I was in Canberra a few years ago we went to the local zoo with Andrew Tridgell (of samba fame). There they had a ferocious penguin that bit me and infected me with a little known disease called penguinitis. Penguinitis makes you stay awake at nights just thinking about penguins and feeling great love towards them. So when Linux needed a mascot, the first thing that came into my mind was this picture of the majestic penguin, and the rest is history.” </li></ul>
  20. 20. Early Linux Growth <ul><li>Red Hat founded in 1993 selling their own distribution and technical support, currently making half a billion dollars a year. </li></ul><ul><li>Unix used to be the major web server operating system, but now Linux is widely used as a web server. </li></ul><ul><li>Throughout the 90s there was massive improvements in usability and a wide growth in the number of programs for Linux. </li></ul>
  21. 21. Who Uses Linux? <ul><li>I am not joking or trying to be trite, but the answer to this question is: every single person in the modern world every day. Everyone who searches Google, picks up a phone and uses telecommunication infrastructure, watches a new televisions, use a new camera, makes a call on many modern cell phones, trades a stock on a major exchange, watches a weather forecast generated on a supercomputer, logs into Facebook, navigates via air traffic control systems, buys a netbook computer, checks out at a cash register, withdraws cash at an ATM machine, fires up a quick-boot desktop (even those with Windows), or uses one of many medical devices; the list goes on and on. </li></ul><ul><li>-Jim Zemlin, the executive director of The Linux Foundation </li></ul>
  22. 22. Current Linux Growth <ul><li>By the 21 st century Linux distributions began to clearly focus on ease of use and ease of install. </li></ul><ul><li>Mandrake/Mandriva Linux was the easiest to install and use in the early part of this century. </li></ul><ul><li>Currently, Ubuntu Linux is the easiest to install with only 6 questions before install begins: </li></ul><ul><ul><li>Including: language, name, time zone, keyboard, confirm hard drive, ready to install? </li></ul></ul>
  23. 23. Blue Linux Red Linux Two Linux One Linux
  24. 28. Mark Shuttleworth <ul><li>Mark Shuttleworth is a South African entrepreneur. </li></ul><ul><li>Lives in London, UK </li></ul><ul><li>Was the second space tourist. </li></ul><ul><li>Was a Debian Developer in the 1990s. </li></ul>
  25. 29. Ubuntu <ul><li>Mark Shuttleworth founded Canonical Ltd in 2004 to develop Ubuntu. </li></ul><ul><li>Ubuntu would focus on ease of use. </li></ul><ul><li>An African word meaning 'Humanity to others', or 'I am what I am because of who we all are'. </li></ul><ul><li>Is a down stream distribution of Debian. </li></ul>