WORKING WITH OPERATING SYSTEM

INTRODUCTION TO WINDOW OPERATING SYSTEM

Microsoft Window is a GUI based operating system that adheres to the features of a good GUI. Multiple applications can be simultaneously run in different window.

The window operating system uses both mouse and keyboard as input devices.

THE DESKTOP

In Window operating system, the screen upon which icons, Windows, etc, are displayed is known as desktop.

THE WINDOW

A window is a typical rectangular area pertaining to an application or a document or a dialog. (a) shows application and document window. (b) Shows a dialog window.

THE APPLICATION WINDOW

An application window has many elements: the title bar, the menu bar, the workspace, the scroll bars, and the corners and borders.

THE TITLE BAR

It is the topmost horizontal bar of each application window and it contains the title of the open window.

THE APPLICATION ICON

·  It is the ions representing the open application. When you click at application icons, a pull- down control menu appears which is also called system menu. Control menu option varies, depending upon the type of application being displayed in the window.

MAXIMISE/Restore

§  This button is used to restore an enlarged window to its previous size or vice versa.

MINIMISE

§  This button shrinks the active window to a button in the taskbar.

CLOSE

§  Choosing this button deactivates the active window from the desktop.

WINDOW TITLE AND ACTIVE FILE NAME

§  Along with the title of the application, title bar also contain the name of file displayed in the application workspace.

THE MENU BAR

The menu bar for an application window is a horizontal bar just below the title bar. The menu bar lists the menus available for that application. Choosing an option from the menu bar result in a pull-down menu.

THE WORKSPACE

This is the area in a window below the title bar and menu bar. Everything that relates to the current application is displayed in the workspace.

THE SCROLL BARS

Depending on the size of a window, the entire application may not be visible. When this happens, the window is outfitted with Vertical and/ or Horizontal scroll bars.

CORNERS AND BORDERS

To resize a window, use the mouse and point to a window’s border or corner. The mouse cursor changes to a double arrow when positioned over a border or corner. Drag the border or corner in the direction indicated by the double arrow to the desired shape.

THE DOCUMENT WINDOW

The document windows are the windows within an application window. These are displayed in the parent application window’s workspace. For example, (a) has three open documents, each of which is shown in a document window. See each of the document windows has its own title bar.

THE ICONS

Icon is a graphic symbol representing a window element. Commonly used icons are: application icons, shortcut icons, document icons, and disk-drive icons.

1)  Application Icons- These are the graphic renderings of the software package’s logo. If you double click over this icon, the related application gets invoked.

2)  Shortcut Icons- These are little graphics pointing to a particular application, document or folder etc. By double clicking over them the concerned application/document/folder etc. becomes active.

3)  Document Icons- The active document window, which is a window within an application window, can be minimized to a document icon.

4)  Disk-drive icons- The disk-drive icon graphically represent five disk-drive options: Floppy-disk, hard-disk, network, RAM, and CD-ROM.

DIRECTORY STRUCTURE OF WINDOWS OS

Storage locations that store files or group of files under them are known as Directories or Folders.

So, directories or folder let you group your files in convenient categories. These directories, in turn, may contain other directories. This organized file structure is referred to as multilevel or hierarchical directory system.

The first level in a multilevel directory system is root directory, which is created automatically at the time of disk formatting. Within the root directory, additional directories and subdirectories can be created. Within each directory or subdirectory, new files or new subdirectories can be created. Directory names follow the files naming convention already mentioned.

CONCEPT OF PATH

Full name of a file or directory consists of path/ primaryname.extension.

Path is a sequence of directory names which give you the hierarchy to access a particular directory or file name.

The full name of a file or a directory is also called pathname.

WILD CARDS

Two special characters, ‘?’ and ‘*’ (asterisk) are called wild cards.

A question mark (p) in a filename or file name extension means that anyone or none character.

Ex:- Memo?.doc would represent

Memo.doc

Memo1.doc

Max. Character=5

Mini. Character=4

THE * WILDCARD

The * (asterisk) replaces any number of character. It can have and max. no. of character.

So*doc. Would represent, all files with doc. Extension

Ex:- *doc = all document files are displace. It has multiple characters.

EXPLORE YOUR COMPUTER

Once your computer is booted up, you are ready to explore your computer i.e., you can now see what all things are there on your computer.

There are several ways that let you navigate around your computer. But most commonly used ones are:

  1. Start button and task bar
  2. My Computer
  3. Window Explorer

THE START BUTTON AND TASKBAR

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, and search for items on your computer and more.

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

MY COMPUTER

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

In Window XP, the things you have on your computer- your programs, documents, and data files, for example- are all accessible from one place called My Computer. My Computer is generally located at the upper left of your Windows screen, or desktop.

WINDOWS EXPLORER

Window Explorer is another way of seeing what is on your computer. Window Explorer shows the computer’s contents as a hierarchy.

STARTING AND CLOSING PROGRAMS

The program available under programs section of Start menu can be started by clicking at Start, then at all programs and at the desired program or group.

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

MANAGING FILE AND FOLDERS

In Window XP, you can organize your documents and programs to suit your preferences. You can store these files in folder, and you can move, copy, and even search for files and folders.

CREATING FOLDERS

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

To create a new folder, click right button of mouse then New then Folder commands are clicked.

FINDING FILES AND FOLDERS

To find file and folder, Start then find then files and folder commands are clicked

RENAMING FILES AND FOLDERS

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

TO MOVE OR COPY A FILE OR FOLDER

To move a file, the file icon or name is firstly selected, then edit and cut commands are clicked. Then the destination folder is opened in a My Computer window and there Edit and paste commands are clicked.

TO COPY A FILE TO A FLOPPY DISK

To copy a file, firstly, the file icon or name is selected, and then edit and copy commands is clicked. Then the destination folder is opened in a My Computer window and there Edit and paste commands are clicked.

TO DELETE A FILE OR FOLDER

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

CREATING SHORTCUTS

To create a shortcut to a file, firstly select the file or folder, whose shortcut is to be created? Then drag the file icon through right mouse button to desired location where shortcut is to be placed. And then select Create Shortcut(s).

SHUTTING DOWN THE COMPUTER

To Shut down the computer, Start then turn off Computer commands are clicked.

TYPES OF SOFTWARE

A computer system consists of hardware and software fot its proper functioning.

Hardware represent the physical and tangible components of the computer i.e., the components that can be seen and touched. Input devices, output devices, CPU, Floppy disk, hard disk etc. are example of computer hardware.

Software represents the set of programs that govern the operation of a computer system and make the hardware run. Software can be classified broadly into two categories.

1)  System Software

2)  Application Software

SYSTEM SOFTWARE

The software that controls internal computer operation is called system software.

The system software can further be classified into two categories:

1)  Operating system

2)  Language Processor.

OPERATING SYSTEM

Operating system is a program which act as an interface between a user and the hardware ( i.e., all computer resources)

An operating system is an important component of a computer system which controls all other components of the computer system. Major components of a computer system are:

  1. The Hardware
  2. The Operating system
  3. The Application program routines (compiler, linkers, database management system, utility programs)
  4. The Humanware (users)

TYPES OF OPERATING SYSTEM

Ø  Single Program OS- It can support on one user or only one program.

Ø  Multiprogramming OS- It support more than one user as a time and can run more than one program.

Ø  Time Sharing OS- The OS user the time sharing techniques. Each active user program is given a fair share of CPU time(s), if the time elapses or an I/O operation is requested, CPU shifts over to the heat job waiting and the previous program is put weight.

Ø  Interface OS- These are interactive in nature. These provide GOI interface to facilities more and easy interaction to the user.

Application Software- An Application software is the set of program necessary to carry out operative for a specified application

LANGUAGE PROCESSORS

·  Assembler- This language processor converts the program written in assembly language into machine language.

·  Interpreter-This language processor converts a HLL program into machine language by converting and executing it line by line.

·  Compiler- It also converts the HLL program into machine language but the conversion manner is different.

APPLICATION SOFTWARE

Application Software- An Application software is the set of program necessary to carry out operative for a specified application.

TYPES OF APPLICATION SOFTWARE

Ø  Packages- Application may be numerous; it is not feasible to design software for each one of them. Rather some general software’s are designed that may be used by individual users in the manner it suits their needs and requirement. Such general—application software are known as packages. Some major and most common categories are:

§  Word processing software- It is a package that processes textual matter and creates organized and flawless documents.

§  Electronic spreadsheets- An Electronic spreadsheet is a program that accepts data in a tabular form (in row and columns) and allows user to manipulate/ calculate/ analyze data in the desired manner.

§  Database Management System (DBMS)- A Database Management System (DBMS) is a package that can handle and manage bulk of stored data.

§  Desktop Publishing Packages- The software that handles page layout by combining the functions of a tradition typesetter and a layout artist, is known as Desktop Publishing Software.

§  Graphics, Multimedia and Presentation applications- The application software that manipulate images is known as Graphic Software and the software that incorporates images, txt, sound, computer animation, and video sequences is known as multimedia software.

The application software that can create professional looking visual aids is called Presentation Graphics Software.

Ø  UTILITIES- Utilities are those application programs that assist the computer by performing housekeeping functions like backing up disk or scanning/ cleaning viruses or arranging information etc.

Ø  CUSTOMISED SOFTWARE- Such software cannot be directly installed at any other user’s workplace as the requirements of the second user may differ from the first and the software may not fit in the requirements of the new user.

TYPES OF SERVICES

  1. Program Execution- The Operating System is responsible for executing various programs whether user programs or system programs i.e., special programs required for the machine functioning.
  2. Handling Input/output Operation- The Operation system is responsible for handling various types of input and various types of outputs in the appropriate manner.
  3. Manipulation of file system- This task involves the making of decisions regarding the storage oof files i.e., where and how a particular file is to be stored.
  4. Error Detection and Handling- the Operation System is also responsible for detecting any type of error that occurs and then properly handling it.
  5. Resource Allocation- This task aims at proper use of resources available.
  6. Accounting- The Operation System keeps an account of what type of functioning is taking place and what type of error have occurred.
  7. Information and Resource Protection- The Operation system is responsible for ensuring that the information and resources available on machine are used in the correct way. The operating system foils the attempts to use them incorrectly.

OPERATION SYSTEM’S FUNCTIONS

Operation system’s functions broadly fall into three categories Essential functions, Monitoring functions and Service functions.

Major OS functions are listed below:

1)  PROCESSOR MANAGEMENT

Throughput is the amount of work accomplished in a given time interval.

e.g., 15 jobs per hour

There are two types of scheduling:

  1. Non-Preemptive scheduling
  2. Preemptive Scheduling

Non-Preemptive Scheduling- A scheduled job always completes before another scheduling decision is made. The scheduling techniques which use non-preemptive scheduling are:

  1. First Come First Served (FCFS) Scheduling
  2. Shortest job Next (SJN) scheduling
  3. Deadline Scheduling

Preemptive scheduling- A scheduling decision can be made even while job is executing. The technique is: Round Robin scheduling and responsible Ratio Scheduling.

STORAGE MANAGEMENT

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