1. System Software CSCI-N 100 Department of Computer and Information Science

2. Operating System A set of programs that perform certain functions Starting the computer Managing programs Distributing memory Coordinating the processor and peripherals Enabling user interaction with the computer

3. Starting the computer Cold boot – power is turned off O/S in ROM (read-only memory) loads BIOS (basic input/output system) into computer memory BIOS conducts Power on self-test (POST) to check for operability BIOS searches for O/S  CMOS (complimentary metal-oxide semiconductor) determines where to look O/S components (kernel) loaded into memory from storage O/S takes control of computer

4. Managing programs Single-tasking Run one application at a time Multi-tasking The ability to run more than one program at a time Foreground – program in use Background – idle program Multi-threading Multiple parts (thread) running simultaneously Multiprocessing Dual core processors or multiple processors

5. Managing Memory Allocates memory area for each running program Keeps programs from leaking into one another  Failure results in corrupt data, programs ‘crash’, error messages  CTRL + ALT + DEL used to close corrupt program Virtual memory an extension of RAM  Data/instructions swapped between RAM and hard drive Works with direct memory access (DMA) to control peripherals access to RAM

6. User Interface Part of the O/S that lets user and computer ‘talk’ to each other Types of operating systems Command line  Requires user to type keywords/commands to enter data/give instructions Graphical User Interface (GUI)  Uses little graphics – icons  User uses a pointing device to enter data/commands Mouse Joystick Keyboard Other types

9. Operating Systems MS-DOS UNIX LINUX MAC OS WINDOWS

10. MS-DOS (command line)

11. UNIX (command line) Developed by AT&T in 1970s First preemptive multitasking system Developed concepts of file management and path names Client/server networking system Widely used by corporations

12. LINUX - Developed in 1991 by UNIX, Competes with Windows and MAC, Powerful and free

13. MAC OS – First GUI (1984) http://www.apple-history.com/movies/1984.mov

14. WINDOWS – 3.X Includes Windows 3.0, 3.1, 3.11, and Windows for Workgroups 3.1 Not a true operating system Uses cooperative multitasking

15. WINDOWS Windows 95 True operating system Uses preemptive multitasking Downward compatible with DOS Considered a transitional system

16. System Utilities System utilities are programs that help the operating system manage the computer system’s resources. Types of utilities: File management File finders Backup utilities Antivirus software File compression Disk scanning File defragmentation

17. File Finder - File finders are programs that enable the user to find files on a storage device

18. File management Known as a file manager. Enables the user to perform various tasks with files, folders, and directories on storage devices. Tasks include: Creating folders Saving, deleting, copying, and moving files and folders Examining the contents of files Launching application programs

19. File Compression - A file compression utility reduces the size of a file.

20. Disk Scanning - A disk scanning utility is a program that detects and fixes physical and logical problems on storage devices

21. File Defragmentation - A file defragmentation utility is a program that moves data on a storage device to improve performance.

26. Apple's 1984: The Introduction of the Macintosh in the Cultural History of Personal Computers by Ted Friedman Revised version of a paper presented at the Society for the History of Technology Convention, Pasadena, California, October 1997. http://www.apple-history.com/movies/1984.mov http://www.duke.edu/~tlove/mac.htm Slide 13

27. Resources http://en.wikipedia.org/wiki/File_managers http://www.explorerxp.com/ http://www.newplanetsoftware.com/systemg/screenshots.php