1 / 33

Chapter 4

Chapter 4. Operating Systems. Need for Operating Systems. It serves as a interface between you and the computer hardware Necessary to manage applications. Parts of an Operating System. 3 major parts: User Interface Kernel File Management. Functions of an Operating System.

royce
Download Presentation

Chapter 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 4 Operating Systems Gene Perkins, Lassen High School Networking Academy

  2. Need for Operating Systems • It serves as a interface between you and the computer hardware • Necessary to manage applications

  3. Parts of an Operating System • 3 major parts: • User Interface • Kernel • File Management

  4. Functions of an Operating System • The OS provides a way for the user to control applications • Works with the BIOS and device drivers to fetch and store data • Contains utilities to optimize the hardware

  5. Operating System Types • Multitasking – more than one application running at the same time • Multiuser – more than one user sharing applications or hardware at the same time • Multiprocessing – more than one processor working at the same time • Multithreading – a program that is broken down into smaller parts and run at the same time

  6. Common Types of OS’s • Windows • 3.x • 9.x (includes ME) • 2000 (includes NT) • XP • Linux • UNIX • Mac OS X (based on UNIX)

  7. DOS • Is a CLI (Command Line Interface) • Made up of 3 boot files: • IO.SYS • MSDOS.SYS • Command.com • Contains file system utilities • Has file management commands

  8. Command Line Screen

  9. DOS Properties • DOS is not user-friendly. The best way to learn about DOS is to use it. • DOS can only run one program at a time. • DOS can only run small programs and has memory limitations (640 Kb max). • DOS is an essential tool for IT professionals and is used extensively for troubleshooting.

  10. File Structure • All files start at the root directory • All other directories branch off of the root directory • Must know the path to find files in DOS • Paths are typed in either relatively or absolute • C:\myfiles\mypicts\nba.gif • \mypicts\nba.gif

  11. Types of DOS Files • Hidden File – The user will not see hidden files when using a normal file search • Read Only – The user can open and read this type of file but cannot modify the file in any way. • Archive – The archive contains a backup copy of files. • System File – The DOS operating system must have these files for a successful boot up.

  12. DOS Commands • DIR – Displays the content of a folder • CD – Change the working directory • MD – Make a new folder (directory) • RD – Removes a folder • DEL – Deletes a file • REN – Renames a files • COPY – Copies a file from one place to another

  13. DOS Commands • SET – Sets a path for programs to work from or to • MEM – Displays the system memory • TYPE – Shows the contents of a file • FDISK – Sets partitions on a hard drive • TIME – Sets system time • DATE – Sets system date • CHKDSK – Checks a drive for errors

  14. DOS Commands • DISKCOPY – Copies a floppy disk to another • EDIT – Opens a file for editing • FORMAT – Prepares the disk to receive data • PRINT – Prints contents of screen or file • ATTRIB – Changes attributes of a file (hidden, read-only, archive) • * - Wildcard that represents everything

  15. Internal & External Commands • Some commands are within the command.com file • Copy • Dir • Some commands are separate files • Xcopy • Format • External commands need to be copied onto a floppy when performing diagnostics procedures

  16. Switches • Most DOS commands can be modified by using a switch behind them • Attrib can be modified to hide or unhide files using the + or – key • Dir /w – Wide format • Dir /a – displays all files • Dir /h – displays hidden files • Each command has special switches it can use (See 4.2.3)

  17. Creating a Boot Disk • Three files are absolutely needed to make a boot disk: • Io.sys • Msdos.sys • Command.com • Other files are also needed to work with the hard drive • Fdisk.exe • Format.com

  18. Creating a Boot Disk • Insert floppy into the drive • Type in the following commands: • format A: /s • Copy C:\format.com A:\format.com • These commands will transfer the system files and other external files needed • The other way is to select from the Start>Settings>Control Panel>Add Progams and select the create boot disk tab

  19. Boot Sequence • BIOS searches for the MBR • The bootstrap loader moves the MBR into RAM • The MBR locates and loads the boot files into memory • Io.sys loads msdos.sys • Msdos.sys runs config.sys • msdos.sys runs command.com • Command.com runs autoexec.bat

  20. Config.sys • Used to modify system parameters • Configures system to run added hardware devices • Installs TSR programs • Redirects program paths • Pressing the F5 or left SHIFT key bypasses config.sys and autoexec.bat • Pressing F8 enters the option screen which allows you to modify bootup

  21. Autoexec.bat • Batch file that can perform any DOS command • Common autoexec.bat commands: • Prompt $P$G – Displays working directory • Set temp=c:\temp – Sets an area to hold data temporarily • Path=C:\;C:\DOS – Sets search path(s) when looking for data • Smartdrive.exe 2048 1024 – Sets 1Mb of memory cache for DOS and 2Mb for Windows

  22. Editing System Configuration Files • Type in edit and file name at dos prompt • Edit autoexec.bat • Type in sysedit in the command prompt box • Edit files in Notepad

  23. DOS Memory • First 640 Kb reserved for running programs • 640 to 1024 Kb used to run older DOS programs and BIOS applications • 1024 to 1088 used for DOS command files • 1088 Kb to 4Gb used for Windows applications

  24. Memory Management • In the config.sys file to disable expanded memory • Device=C: \Windows\Emm386.exe NOEMS • To load DOS into upper memory • DOS=UMB • To allow DOS to use high memory • DOS=HIGH, UMB

  25. Memory Management • To allow DOS programs access to expanded memory • Device=C: \Windows\Emm386.exe RAM • To allow device drivers to load into high memory • DEVICEHIGH=C: \DOS\MOUSE.SYS • This allows Windows 3.x and 9x to work • DEVICE=C: \DOS\HIMEM.SYS

  26. Virtual Memory • When a section of the hard drive is set aside to be used as the system RAM • The slowest memory available • Usually set to automatically adjust as needed • If there is inadequate virtual memory, your system will freeze • Stored in WIN386.SWP (Win9x) or PAGEFILE.SYS (Win2000)

  27. RAM Drive • In some cases, RAM can be setup to act as a hard drive • Configured in config.sys using this command: • DEVICE=C:\DOS\ RAMDRIVE.SYS 4096 • When data is stored in this manner, it can be lost when powered off

  28. General Protection Faults • When windows crashes (blue screens), there is a problem with 2 programs trying to share the same spot in memory • Can also be caused by bad drivers or trying to directly gain access to windows programs • GPF’s can also cause the program to lock

  29. Real vs Protected Mode • Real mode is used with DOS • System crash will bring down the whole system • Protected mode used with Windows • Allows a program to crash without affecting the system

  30. Perform Practice Test

More Related