Computer Operating Systems And Software applications

2 An operating system (OS) is the master controller for all of the activities that take place within a computer. –Microsoft Windows XP & 7, Mac OS, Linux, UNIX The operating system also interacts with application software, device drivers and hardware to manage a computer’s resources Operating System Overview: What does an operating system do?

3 What does an operating system do?

4 Why does an operating system need to manage memory? When you want to run more than one program at a time, the OS has to divide up memory and set aside RAM for each program The OS must ensure that instructions and data from one area of memory don’t “leak” into an area allocated to another program If it fails, data can get corrupted, programs can “crash” and your computer will display error messages such as “General Protection Fault”

5 The OS acts as a filing clerk that stores and retrieves files from your disks and CDs –It remembers the names and locations of all your files –It keeps track of empty spaces where new files can be stored How does the OS keep track of storage resources?

6 To ensure that they function correctly OS communicates with the device driver software so that the data can travel smoothly between the computer and the peripheral device OS controls peripherals to ensure input and output proceeds in an orderly fashion Why does the operating system get involved with peripheral devices?

7 A user interface can be defined as the combination of hardware and software that helps people and computers communicate with each other Two types of user interfaces –Graphical user interface (GUI) provides a way to point and click a mouse to select menu options and manipulate graphical objects that are displayed on the screen How does the operating system affect the user interface?

8 –Command-line user interface requires users to type various memorized commands to run programs and accomplish tasks How does the operating system affect the user interface?

9 Stored on the hard disk on most computers The OS’s small bootstrap program resides on the Master Boot Record (MBR) and provides the instructions to load the core parts into memory when system boots –These core components are called the kernel, and provides the most essential OS services, such as memory management and file access The kernel stays in memory all the time your computer is on Other parts of the OS, such as customization utilities, are loaded into memory as they are needed Where is the operating system?

10 Yes, typically through helpful tools called utilities, which are used to –Launch programs –Manage files –Get help –Customize the user interface –Configures equipment Do I ever interact directly with the OS?

11 Microsoft Windows –Installed on over 80% of the world’s PCs –Since its introduction in 1985, it has evolved through several versions, such as Windows 3.1, NT, 95, 98, Me, 2000, XP and Windows 7. Mac OS –Used with Macintosh computers, manufactured by Apple Computer. Inc. –PC and Mac platforms are not compatible Platform refers to the combination of a computer’s microprocessor and OS What are the most popular operating systems?

12 UNIX –Developed in 1969 –Command-line interface –Many versions became available for mainframes and microcomputers Linux –Developed in 1991 by Linus Torvald as a school project, based on UNIX –Linux is free –Popular OS for and Web servers –Most Linux versions have a GUI interface Red Hat Linux, Caldera OpenLinux, Debian, SuSE What are the most popular operating systems?

13 Developed several years before windows, it still has a GUI interface Both have windows, icons, menus and pointers Is Mac OS similar to windows?

14 The Mac OS

15 Linux

16 First operating system that most people have used DOS (Disk Operating System) was developed by Microsoft Is part of the operating system kernel of Windows 3.1, 95, 98 and ME –DOS is well hidden behind the Windows GUI –Found in the MS-DOS Prompt in the Start menu Why do I keep hearing about DOS?

17 “DOS Command-Line Interface” Classic Course Labs Found in your Computer Concepts BookOnCD Why do I keep hearing about DOS?

18 What are the options for PDA operating systems? Palm OSWindows Mobile OS

19 1.To run more than one program at a time, the OS must allocate specific areas of _______ for each program. 2.A _______ is the combination of hardware and software that helps people and computers communicate. 3.The core part of an OS is called its _______. 4.List 3 popular operating systems: _______, _______, _______ 5.Windows uses a _______ interface. 6.DOS uses a _______ interface. Self Quiz Questions

20 1.To run more than one program at a time, the OS must allocate specific areas of RAM for each program. 2.A user interface is the combination of hardware and software that helps people and computers communicate. 3.The core part of an OS is called its kernel. 4.List 3 popular operating systems: Windows, Mac OS, Linux 5.Windows uses a graphical user interface. 6.DOS uses a command-line interface. Self Quiz Questions

21 “Using the Windows Interface” New Perspectives Labs Found in your Computer Concepts BookOnCD Why do I keep hearing about DOS?