Working with Operating System

* An Operating System is a program which acts as an interface between a user and the hardware.

* The major funtions of Operating system are:

1. Program Execution
2. Handling Input/Output operations
3. Manipulation of file system
4. Error detection and handling.
5. Resources allocationv
6. Accounting
7. Information and Resource Protection

* Windows XP is a GUI based operating system. In windows operating system, multiple applications can be simultaneously run in different windows.

* In Window XP, the screen upon which icons, windows, etc. are displayed is known as dextop.

* A window is a typical rectunglar area pertaining to an application or a document or a dialog.

* An icon is a graphic symbol that represents a window element like file, folder or shortcut.

* Loading up of operating system files into the computer's memory is called booting up.


* You can explore your computer through start button & Taskbar, my computer and Windows Explorer.

* The Taskbar is a bar, which is usually located at the bottom of the screen.

* The Start button is located at taskbar. By clicking at Start button, Start menu appears wherefrom you can start programs, open documents, customize your system, get help, search for items on your computer and more.


* My computer is helpful for viewing the contents of a single folder or drive.

* windows Explorer is another way of seeing what is on your computer. Windows Explorer shows the computer's content as a hierarchy.

* The progames available under Programes section of Start menu can be started by clicking at start, then at All Programes and then at the desired program or group.

* To quit an open program, just click at Close button.

* A folder is a location in which you can store files and other folders.

* To create a new folders, File - New - Folder commands are clicked in My Computer windows.

* To find files or folders, Start - Find - Files or Folders commands are clicked.

* To rename a File, firstly the file icon or name is selected and then File - Rename commands are clicked.

* To move a file, the file icon or name is firstly selected, then Edit - Cut commands are clicked. Then the destination folder is opened in a My computer window and there Edit - Paste commands are clicked.

* To copy a file, firstly, the icon or name is selected, then Edit - Copy command is clicked. Then the destination folder is opened in a My Computer window, and there Edit - Paste command are clicked.

* To delete a file, a folder, firstly select the file icon or name and then either click Delete key or click File - Delete command.

* To create a shortcut to a file, firstly select the file or folder, whose shorcut is to be created. Then drag is to be placed. And then select Create Shortcut(s).

* To shut down the computer, Start - Turn Off Computer commands are clicked.

* The Operating System performs following major functions:

1. Processor Management.
2. Storage Management.
3. Information Management.

* The Processor Management function aims at attaining maximum possible throughout.

* Throughout is the amount at work accomplished in a given time interval.

* Two types of job scheduling is performed: non-preemptive and preemptive scheduling.

* In non-preemptive scheduling, a scheduled job always completes before another scheduling decision is made. In preemtive scheduling, a scheduling decision can be made even while job is executing. The techniques that use this type of scheduling are: Round Robin Scheduling and Response Ratio Scheduling.

* The storage management function aims at minimum wastege of storage area as well as program protection and security.

* The information management function aims at providing, processing, maintaining and protecting information.


NOTES


* OS stands for Operating System.

* In classic view, installed programes are used through Start - Programs rather than Start - All programes, which is the way of doing the same in XP view.

* Another way to open windows Explorer is to use the right mouse button to click the My computer icon. The click Explorer.

* Loading up of operating system files into the computer's memory is called booting up. The booting up is the first thing that takes place when you switch on you computer.

* In Windows Explorer, to show or hide folders on the left side of the window, click the plus or minus sign beside the folder.

* A drive being shared through a network i.e, interconnected computer.

* File names in Window Xp can be upto 255 characters includind spaces. However, file name cannot contain any of these characters: \/;*?<>

* A quick way to move and copy files and folder is to use right mouse button to invoke shortcut menu.

* If you delete a file at the command prompt or from a floppy disk(A: or B: drive), it does not go into the Recycle Bin.

* When you "empty" the Recycle Bin, the contents of RecycleBin are permanently removed from the disk. Before this, the deleted contents remain on the disk, but are unaccessible. To empty the Recycle Bin, right click the Recycle Bin icon on the desktop and click Empty Recycle Bin at the shortcut menu displayed. eleted files cannot be recalled or undeleted onceyou empty the Recycle Bin.

* A shortcut that appears on the desktop can be copied or moved to another location also.

* File System refers to storage mechanism. To popular file-systems for Windows OS are FAT and NTFS. Further discussion on file systems is beyong the scope of this book.

* Do not turn your computer until you see a message telling you that shut down is complete. If you turn off your computer without shutting it down correctly, you risk losing information.

* CPU is generally termed as processor.

* Actually and Originally, 'Linux' was used to refer to the Kernel of the O/S.

* The actual program-code(written by programmers) of the software.

* Kernel is the fundamental part of an operating system. It responsible for providing secure access to machine's hardware and another resource to computer programs.

DEFINATIONS


Operating System: Interface between a user and the hardware.
Shortcut menu: A menu that displayes the most commonly used commands in a particular context.
Document: A file you create when you work in a program.
File: A program or document stored on a disk.
Folder: A location in which you can store files and other folders.
Icon: A picture representing a program, disk drive, file, folders or specific tasks.
Applications: A group of instructions your computer uses to perform specific tasks.
Shortcut: An icon that links to a file or folder.
Toolbar: A set of buttons you click to peform common tasks.
Window: The rectangular portions of screen that displyes an open program or the contents of a folder or disk.
Desktop: The workspace on the computer screen, hosting the most widely used application's and features icons.