computer_basics:operating_system_fundamentals
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computer_basics:operating_system_fundamentals [2012/09/26 04:24] – mithat | computer_basics:operating_system_fundamentals [2019/12/05 04:11] – [Booting step 6/: Authenticate user] mithat | ||
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Mithat Konar\\ | Mithat Konar\\ | ||
- | Sept. 25, 2012 | + | Dec. 4, 2019 |
===== The Operating System ===== | ===== The Operating System ===== | ||
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* Five basic OS functions: | * Five basic OS functions: | ||
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+ | |||
+ | ===== OS Function 1: Starting the computer ===== | ||
+ | * OS's first job is to load itself into RAM | ||
+ | * Called **booting**. | ||
===== OS Function 1: Starting the computer ===== | ===== OS Function 1: Starting the computer ===== | ||
- | * The OS's first job is to loads itself into RAM | ||
- | * Called **booting** | ||
- | * Booting involves //six steps// | ||
- | ===== Booting process ===== | ||
{{: | {{: | ||
- | Six steps in starting the computer | + | Booting: six steps |
- | ===== OS Function | + | ===== Booting step 1: BIOS and EFI ===== |
- | * //**Booting Step 1**//: Load **BIOS (Basic Input/ | + | * Many computers use a **BIOS (Basic Input/ |
- | * Allows computer to | + | * The first thing that is loaded |
- | * Accept keyboard input | + | * Manages some core hardware settings. |
- | * Show information on the monitor | + | * Handles the very first stages of the booting process. |
+ | * Usually stored in flash memory or CMOS memory chip. | ||
- | ===== OS Function | + | ===== Booting part 1: BIOS and EFI ===== |
- | * //**Booting Step 2**//: Conduct the **power-on self-test (POST)** | + | |
- | * Confirms that both the computer and its peripheral devices are working properly. | + | |
- | ===== OS Function 1: Starting the computer ===== | + | |
- | | + | * ** UEFI (Unified Extensible Firmware Interface)** is one example. |
- | * BIOS loads into memory the **kernel**, the central part of the OS | + | * Like a mini OS. |
- | * The OS then loads remainder of what's needed | + | * Does everything BIOS does. |
+ | * Lets user run small utility applications that run on the Extensible Firmware Interface. | ||
+ | * Considered more secure than traditional BIOS. | ||
- | ===== OS Function 1: Starting | + | ===== Booting step 2: Test the hardware |
- | * //**Booting Step 4**//: Check the system configuration | + | * Many BIOS/EFIs initiate a **power-on self-test (POST)** or similar test. |
- | * The OS checks | + | * Confirms that both the computer and its peripheral devices |
- | * The OS installs and loads needed drivers | + | |
- | ===== OS Function 1: Starting | + | ===== Booting step 3: Load the operating system |
- | * //**Booting Step 5**//: Load system utilities | + | * BIOS or EFI loads an OS' |
- | * Antivirus software | + | * kernel: the central part of the OS. |
- | * Speaker volume control | + | * Usually stored on main storage device. |
- | * Etc. | + | * The OS then loads remainder of what's needed. |
+ | |||
+ | ===== Booting step 4: Check the system configuration ===== | ||
+ | * The OS checks the system configuration for **device drivers**. | ||
+ | * device driver: utility program that enables communication between the OS and a peripheral device. | ||
+ | * The OS installs and loads the needed drivers. | ||
- | ===== OS Function 1: Starting the computer | + | ===== Booting step 5: Load system utilities |
- | * //**Booting | + | * Antivirus software |
- | * If necessary, | + | |
+ | | ||
+ | |||
+ | ===== Booting | ||
+ | * Final part of booting is to facilitate | ||
+ | * Typically | ||
===== OS Function 2: Managing applications ===== | ===== OS Function 2: Managing applications ===== | ||
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===== OS Function 3: Managing memory ===== | ===== OS Function 3: Managing memory ===== | ||
- | * The OS gives each program a portion of RAM memory | + | * The OS |
- | * OS processes often involve using a **buffer** | + | * gives each program a portion of RAM memory. |
- | * An area that holds data temporarily to make programs run faster | + | * keeps them from interfering with each other. |
- | * RAM memory functions as the buffer | + | |
===== OS Function 3: Managing memory ===== | ===== OS Function 3: Managing memory ===== | ||
- | * RAM is organized into **pages**: units of large fixed size containing program instructions and data. | + | * RAM is organized into **pages**: units of large fixed size. |
* **Virtual memory** uses a portion of the hard disk to extend RAM. | * **Virtual memory** uses a portion of the hard disk to extend RAM. | ||
- | * When RAM is full, copies | + | * When RAM is full, the contents |
+ | * When the page is again needed, it is transferred back into RAM. | ||
* Transferring files between RAM and the hard disk is called **paging**. | * Transferring files between RAM and the hard disk is called **paging**. | ||
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===== OS Function 3: Managing memory ===== | ===== OS Function 3: Managing memory ===== | ||
- | * Adding more RAM is often the best way to improve computer performance because: | + | * Adding more RAM is often a good way to improve computer performance because: |
* Paging slows the computer | * Paging slows the computer | ||
* Accessing data from the hard disk is slower than accessing it from RAM | * Accessing data from the hard disk is slower than accessing it from RAM | ||
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* Device drivers enable communication between the OS and input and output (and other) devices. | * Device drivers enable communication between the OS and input and output (and other) devices. | ||
- | ===== OS Function 5: Providing the user interface ===== | + | ===== OS Function 5: Provide a user interface ===== |
* The **user interface** allows the user to: | * The **user interface** allows the user to: | ||
* Start application programs | * Start application programs | ||
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===== User interfaces ===== | ===== User interfaces ===== | ||
{{: | {{: | ||
- | (a) graphical, | + | a) graphical, b) menu-driven, |
- | ===== OS Function 5: Providing | + | ===== OS Function 5: Provide |
- | * Types: | + | * Types of user interfaces: |
* **graphical user interface (GUI)** uses **icons** and other visual metaphors. | * **graphical user interface (GUI)** uses **icons** and other visual metaphors. | ||
- | * **menu-driven** | + | * **menu-driven |
* Provides text-based menus | * Provides text-based menus | ||
* Displays available user options | * Displays available user options | ||
- | * **command-line interface: | + | * **command-line interface**: |
* Requires the user to type commands to instruct the OS to perform the desired actions | * Requires the user to type commands to instruct the OS to perform the desired actions |
computer_basics/operating_system_fundamentals.txt · Last modified: 2019/12/06 05:11 by mithat