Introduction
When you turn on your computer system, it's nice to think that you're in control. There's the trusty computer mouse, which you can move anywhere on the screen, summoning up your music library or Internet browser at the slightest whim. Although it's easy to feel like a director or a manager in front of your desktop or laptop console, there's a lot going on inside, and the real man behind the curtain handling the necessary tasks is the operating system. Operating system to any computer is the house keep and the brain behind every operations.
Most desktop or laptop PCs come pre-loaded with Microsoft Windows operating. Macintosh computers come pre-loaded with Mac OS X. Many corporate servers use the Linux or UNIX operating systems. The operating system (OS) is the first thing loaded onto the computer -- without the operating system, a computer is useless.
More recently, operating systems have started to pop up in smaller computers as well. If you like to tinker with electronic devices, you're probably pleased that operating systems can now be found on many of the devices we use every day, from cell phones to wireless access points. The computers used in these little devices have gotten so powerful that they can now actually run an operating system and applications. The computer in a typical modern cell phone is now more powerful than a desktop computer from 20 years ago, so this progression makes sense and is a natural development.
The purpose of an operating system is to organize and control hardware and software so that the device it lives in behaves in a flexible but predictable way. In this lesson, we'll tell you what a piece of software must do to be called an operating system, show you how the operating system in your desktop computer works and give you some examples of how to take control of the other operating systems around you.
1.1.1 Objective of the Lesson
At the end of this lesson, you would be able to:
· The Definition of Operating System
· Explain the term computer operating system
· Types of operating System
· Functions of Operating System
· Computer Operating System
· Know Some computer terminologies
1.2 What is Operating System?
An operating system (OS) is a set of system software programs in a computer that regulate the ways application software programs use the computer hardware and the ways that users control the computer system. For hardware functions such as input/output and memory space allocation, operating system programs act as an intermediary between application programs and the computer hardware and the user.
Because early computers were built to perform a series of single tasks, like a calculator, operating systems did not exist in their modern and more complex forms until the early 1960s. Some operating system features were developed in the 1950s, such as programs that could automatically run different programs in succession to speed up processing. Hardware features were added that enabled use of runtime libraries, interrupt, and parallel processing. When personal computers by companies such as Apple Inc., Atari, IBM and Amiga became popular in the 1980s, vendors adding operating system features that had previously become widely used on mainframe and mini computers. Later many features such as graphical user interface were developed specifically for personal computer operating systems.
An operating system can be divided into many different parts. One of the most important parts is the kernel, which controls low-level processes that the average user usually cannot see: it controls how memory is read and written, the order in which processes are executed, how information is received and sent by devices like the monitor, keyboard and mouse, and deciding how to interpret information received by networks. The user interface is the part of the operating system that interacts with the computer user directly, allowing them to control and use programs. The user interface may be graphical with icons and a desktop, or textual, with a command line. Another similar feature is an Application programming interface, which is a set of services and code libraries that let applications interact with one another, as well as the operating system itself. Depending on the operating system, many of these components may not be considered an actual part. For example, Windows considers its user interface to be part of the operating system, while many versions of Linux do not.
1.2 Types of operating System
We all know that the operating system is the most important software running on your computer without which one cannot run even the application software's which are designed to communicate with the hardware through the operating system. Are you aware that there are many types of operating systems available in the market to suit various needs and machines?
The types of the operating systems can be classified as single user program and multi tasking. A single user program operating system allows only one program to run at a time. This was the operating system that was improved on to as multi-tasking operating systems as it was not practical to close one application to open another, example, close a word document to open power point, especially if you are required to copy some texts from Microsoft word to Microsoft power point.
· Multi tasking operating systems enables a single user to have two or more applications open at the same time. It gives the computer the option to decide on how many time slices each program is allocated. The active program gets the most, and the rest is divided according to the factors of which programs are doing tasks although not active, and the last priority is given to programs and applications that are left open but are not doing anything.
· Multi tasking operating systems can be divided into three general types depending on the type of computer and the type of applications that will be run. These are Real time operating systems, Single user-Multi tasking, Multi user operating systems
· Real time operating systems (RTOS) are mainly used to control machinery, scientific instruments, industrial systems, etc. Here the user does not have much control over the functions performed by the RTOS.
· Single user, multi tasking operating systems are the systems that allow a single user to run different applications at the same time. Windows of Microsoft and Macintosh of Apple are the most commonly used single user, multi tasking operating systems.
· Multi user operating systems give access at the same time to the resources on a single computer to many users. Unix is one such operating system.
The most commonly used operating systems that fall under the above categories are, Windows 95, Windows 98, Windows Me, Windows NT, Windows 2000, Windows XP (Which is an upgrade of all the earlier and comes in two versions as Home and Professional. The professional version is the same as the home edition but has additional features, like networking and security features.), Windows Vista, Windows CE, Apple Macintosh, Unix, etc.
1.4 Functions of Operating System
Today most operating systems perform the following important functions:
· Processor management, that is, assignment of processor to different tasks being performed by the computer system.
· Memory management, that is, allocation of main memory and other storage areas to the system programmes as well as user programmes and data.
· Input/output management, that is, co-ordination and assignment of the different output and input device while one or more programmes are being executed.
· File management, that is, the storage of file of various storage devices to another.
· It also allows all files to be easily changed and modified through the use of text editors or some other files manipulation routines.
· Establishment and enforcement of a priority system. That is, it determines and maintains the order in which jobs are to be executed in the computer system.
· Automatic transition from job to job as directed by special control statements.
· Interpretation of commands and instructions.
· Coordination and assignment of compilers, assemblers, utility programs, and other software to the various user of the computer system.
· Facilities easy communication between the computer system and the computer operator (human). It also establishes data security and integrity.
1.5 names of some Computer Operating System
Microsoft Windows, Mac OS X, Linux, FreeBSD, NetBSD, OpenBSD, MS-DOS, FreeDOS, AmigaOS, BeOS, MorphOS, QNX, OS4000, VxWorks, ReactOS, DR-DOS, Solaris, TOS, GEM, NetWare, OpenVMS, Syllable, Haiku, AROS, MenuetOS, KolibriOS, LynuxWorks, Multics, System/360, Unix
3.36 COMPUTER GLOSSARY
· Access Memory (RAM): Memory that can be read from or written to by a computer or other devices. Information stored in RAM is lost when the computer is turned off.
· Active Directory, The directory service that stores information about objects on a network and makes this information available to users and network administrators. Active Directory gives network users access to permitted resources anywhere on the network using a single logon process. It provides network administrators with an intuitive, hierarchical view of the network and a single point of administration for all network objects.
· Active, Describes the window or icon that you are currently using or that is currently selected. The operating system always applies the next keystroke or command you choose to the active window. Windows or icons on the desktop that are not selected are inactive.
· Background, The screen background image used on a graphical user interface such as Windows. Any pattern or picture that can be stored as a bitmap (.bmp) file can be set as a screen background.
· Bit, The basic unit of information in a binary numbering system. Computer work with binary numbers, and the internal circuit can represent one of the two numbers in a binary system 1 or 0. This basic either/or, yes/no units of information are called bits.
· Boot, The process of starting or resetting a computer. When first turned on (cold boot) or reset (warm boot), the computer runs the software that loads and starts the computer's operating system, which prepares it for use. Booting initiate automatic routine that clears the memory loads the operating system, and prepares the computer for use. The term boot is derived form saying "pulling yourself up by your own bootstraps" personal computers must just do that because Random Access Memory (RAM) does not retain program instruction which the power is shut off.
· Byte, Pronounced "bite" eight contiguous bits, the fundamental data word of personal computers. It provides a basic unit of measurement for computer storage.
· CD-R: Recordable compact disc. Data can be copied to the CD on more than one occasion; however, data cannot be erased from the CD.
· CD-RW, Rewritable compact disc. Data can be copied to the CD on more than one occasion and can be erased.
· Chips, A miniaturized electronic circuit mass produced on a tiny chip or wafer of silicon.
· Commands, A user uninitiated signal given to a computer to controls the execution of a specific operation.
· Cursor, An on-screen-blinking character that show where next operation will take place.
· Default printer, The printer to which a computer sends documents if you select the Print command without first specifying which printer you want to use with a program. You can have only one default printer; it should be the printer you use most often.
· Desktop, The on-screen work area on which windows, icons, menus, and dialog boxes appear.
· Device driver, A program that allows a specific device, such as a modem, network adapter, or printer, to communicate with the operating system. Although a device might be installed on your system, Windows cannot use the device until you have installed and configured the appropriate driver. If a device is listed in the Hardware Compatibility List (HCL), a driver is usually included with Windows. Device drivers load automatically (for all enabled devices) when a computer is started, and thereafter run invisibly.
· Device, Any piece of equipment that can be attached to a network or computer; for example, a computer, printer, joystick, adapter, or modem card, or any other peripheral equipment. Devices normally require a device driver to function with Windows.
· Dialog box, A secondary window that contains buttons and various kinds of options through which you can carry out a particular command or task.
· Digital video disc (DVD), A type of optical disc storage technology. A digital video disc (DVD) looks like a CD-ROM disc, but it can store greater amounts of data. DVDs are often used to store full-length movies and other multimedia content that requires large amounts of storage space.
· Disk, A storage device that is attached to a computer.
· Document, Any self-contained piece of work created with an application program and, if saved on disk, given a unique file name by which it can be retrieved.
· Drag, To move an item on the screen by selecting the item and then pressing and holding down the mouse button while moving the mouse. For example, you can move a window to another location on the screen by dragging its title bar.
· Drive letter, The naming convention for disk drives on IBM and compatible computers. Drives are named by letter, beginning with A, followed by a colon.
· Drive, An area of storage that is formatted with a file system and has a drive letter. The storage can be a floppy disk, a CD, a hard disk, or another type of disk. You can view the contents of a drive by clicking its icon in Windows Explorer or My Computer.
· DVD drive, A disk storage device that uses digital video disc (DVD) technology. A DVD drive reads both CD-ROM and DVDs; however, you must have a DVD decoder to display DVD movies on your computer screen.
· Expansion slot, A socket in a computer, designed to hold expansion boards and connect them to the system bus.
· Filename, A name assigned to a file (document) so that the operating system can find the file. You assign file names when the file is created. Every file on a disk must have a unique name.
· Folder, A container for programs and files in graphical user interfaces, symbolized on the screen by a graphical image (icon) of a file folder. A folder is a means of organizing programs and documents on a disk and can hold both files and additional folders.
· Font; A graphic design applied to a collection of numbers, symbols, and characters. A font describes a certain typeface, along with other qualities such as size, spacing, and pitch.
· Gigabyte (GB), 1,024 megabytes, though often interpreted as approximately one billion bytes.
· GIGO, (Garbage In, Garbage Out), This means that the output you get from the system depends directly on what you key-in as your inputs.
· Hard disk, A device, also called hard disk drive, that contains one or more inflexible platters coated with material in which data can be recorded magnetically with read/write heads. The hard disk exists in a sealed case that protects it and allows the head to fly 10 millionths to 25 millionths of an inch above the surface of a platter. Data can both be stored and accessed much more quickly than on a floppy disk.
· Hardcopy, Printed output from the system distinguished from data stored on disk or in memory.
· Hardware, The physical components of a computer system, including any peripheral equipment such as printers, modems, and mouse devices.
· Icon, A small image displayed on the screen to represent an object that can be manipulated by the user. Icons serve as visual mnemonics and allow the user to control certain computer actions without having to remember commands or type them at the keyboard.
· Input/output (I/O) port, A channel through which data is transferred between a device and the microprocessor. The port appears to the microprocessor as one or more memory addresses that it can use to send or receive data.
· Insertion point, The place where text will be inserted when typed. The insertion point usually appears as a flashing vertical bar in an application's window or in a dialog box.
· Install, When referring to software, to add program files and folders to your hard disk and related data to your registry so that the software runs properly. Installing contrasts with upgrading, where existing program files, folders, and registry entries are updated to a more recent version.
· Internet, A worldwide network of computers. If you have access to the Internet, you can retrieve information from millions of sources, including schools, governments, businesses, and individuals.
· Kilobyte, The basic unit of measurement for computer memory equal to 1,024 bytes.
· Maximize, To enlarge a window to its largest size by clicking the Maximize button (at the right of the title bar), or by pressing ALT+SPACEBAR and then pressing X.
· Media, Any fixed or removable objects that store computer data. Examples include hard disks, floppy disks, tapes, and compact discs.
· Minimize, To reduce a window to a button on the taskbar by clicking the Minimize button (at the right of the title bar), or by pressing ALT+SPACEBAR and then pressing N.
· Monitor, The complete device that produces an on-screen display, including all necessary internal support circuiting. A monitor is also called a Video Display Unit (VDU) or cathode-rye tube (CRT).
· My Documents, A folder that provides you with a convenient place to store documents, graphics, or other files you want to access quickly. When you save a file in a program such as WordPad or Paint, the file is automatically saved in My Documents, unless you choose a different folder.
· Network, A group of computers and other devices, such as printers and scanners, connected by a communications link, enabling all the devices to interact with each other. Networks can be small or large, permanently connected through wires or cables, or temporarily connected through phone lines or wireless transmissions. The largest network is the Internet, which is a worldwide group of networks.
· Operating System; Is a group of program that act as a translator between you, the operator, and your computer system. It is the program that controls the processing of information in the computer. In all, it's regulates the operation of the computer system. Operating system is the Brian behind the computer operations. It is also known as a master control program in the computer system.
· OS/2, A protected-mode, virtual memory, multitasking operating system for personal computers based on the Intel 80286, 80386, i486, and Pentium processors. OS/2 can run most MS-DOS-based programs and can read all MS-DOS disks.
· Output Unit, The component of the computer system that takes care of displaying or printing the results of processing operation.
· Peripheral, A device, such as a disk drive, printer, modem, or joystick, that is connected to a computer and is controlled by the computer's microprocessor.
· Printer, A device that puts text or images on paper or other print media. Examples are laser printers or dot-matrix printers.
· Program, A complete, self-contained set of computer instructions that you use to perform a specific task, such as word processing, accounting, or data management. Program is also called application. A list of instruction in a computer programming language that tells the computer what to do.
· Random access memory (RAM), Memory that can be read from or written to by a computer or other devices. Information stored in RAM is lost when the computer is turned off.
· Recycle Bin, The place in which Windows stores deleted files. You can retrieve files you deleted in error, or you can empty the Recycle Bin to create more disk space.
· ROM, An acronym for Read-Only Memory, a semiconductor circuit into which code or data is permanently installed by the manufacturing process. ROM contains instructions or data that can be read but not modified
· Screen saver, A moving picture or pattern that appears on your screen when you have not used the mouse or keyboard for a specified period of time.
· Select, To specify a block of data or text on screen by highlighting it or otherwise marking it, with the intent of performing some operation on it.
· Serial port, An interface on the computer that allows asynchronous transmission of data characters one bit at a time. Also called a communication or COM port.
· Server, In general, a computer that provides shared resources to network users.
· Shortcut, A link to any item accessible on your computer or on a network, such as a program, file, folder, disk drive, Web page, printer, or another computer. You can put shortcuts in various areas, such as on the desktop, on the Start menu, or in specific folders.
· System disk, A disk that contains the MS-DOS system files necessary to start MS-DOS.
· System files, Files used by Windows to load, configure, and run the operating system. Generally, system files must never be deleted or moved.
· Taskbar button, A button that appears on the taskbar and corresponds to a running application.
· Taskbar, The bar that contains the Start button and appears by default at the bottom of the desktop. You can click the taskbar buttons to switch between programs. You can also hide the taskbar, move it to the sides or top of the desktop, and customize it in other ways.
· Terminal, A device consisting of a display screen and a keyboard that is used to communicate with a computer.
· Text box, In a dialog box, a box in which you type information needed to carry out a command. The text box may be blank or may contain text when the dialog box opens.
· Thumbnail, A miniature version of an image that is often used for quick browsing through multiple images.
· Title bar, The horizontal bar at the top of a window that contains the name of the window. On many windows, the title bar also contains the program icon, the Maximize, Minimize, and Close buttons, and the optional button for context-sensitive Help. To display a menu with commands such as Restore and Move, right-click the title bar.
· ToggleKeys, A feature that sets your keyboard to beep when one of the locking keys (CAPS LOCK, NUM LOCK, or SCROLL LOCK) is turned on or off.
· Toolbar, In a program in a graphical user interface, a row, column, or block of on-screen buttons or icons. When clicked, these buttons or icons activate certain functions, or tasks, of the program. For example, the toolbar in Microsoft Word contains buttons for, among other actions, changing text to italic or boldface, and for saving or opening a document. Users can often customize toolbars and move them around on the screen.
· Tree view, A hierarchical representation of the folders, files, disk drives, and other resources connected to a computer or network. For example, Windows Explorer uses a tree view to display the resources that are attached to a computer or a network.
· Uninstall: When referring to software, the act of removing program files and folders from your hard disk and removing related data from your registry so the software is no longer available. When referring to a device, the act of removing the corresponding device drivers from your hard disk and physically removing the device from your computer.
· UNIX, A powerful, multiuser, multitasking operating system initially developed at AT&T Bell Laboratories in 1969 for use on minicomputers. UNIX is considered more portable, that is, less computer-specific, than other operating systems because it is written in C language. Newer versions of UNIX have been developed at the University of California at Berkeley and by AT&T
· Unix; A powerful, multiuser, multitasking operating system initially developed at AT&T Bell Laboratories in 1969 for use on minicomputers. UNIX is considered more portable, that is, less computer-specific, than other operating systems because it is written in C language. Newer versions of UNIX have been developed at the University of California at Berkeley and by AT&T.
· USB port, An interface on the computer that enables you to connect a Universal Serial Bus (USB) device. USB is an external bus standard that enables data transfer rates of 12 Mbps (12 million bits per second). USB ports support a plug that is approximately 7 mm x 1 mm.
· User, A person who uses a computer. If the computer is connected to a network, a user can access the programs and files on the computer, as well as programs and files located on the network (depending on account restrictions determined by the network administrator).
· Video adapter, An expansion board that plugs into a personal computer to give it display capabilities. A computer's display capabilities depend on both the logical circuitry (provided in the video adapter) and the monitor. Each adapter offers several different video modes. The two basic categories of video modes are text and graphics. Within the text and graphics modes, some monitors also offer a choice of resolutions. At lower resolutions a monitor can display more colors. Modern adapters contain memory, so that the computer's RAM is not used for storing displays. In addition, most adapters have their own graphics coprocessor for performing graphics calculations. These adapters are often called graphics accelerators.
· Virus, A program that attempts to spread from computer to computer and either cause damage (by erasing or corrupting data) or annoy users (by printing messages or altering what is displayed on the screen).
· Wildcard character, A keyboard character that can be used to represent one or many characters when conducting a query. The question mark (?) represents a single character, and the asterisk (*) represents one or more characters.
· Window, A portion of the screen where programs and processes can be run. You can open several windows at the same time. For example, you can open your e-mail in one window, work on a budget in a spreadsheet in another, download pictures from your digital camera in another window, and order your weekly groceries on the Web in another window. Windows can be closed, resized, moved, minimized to a button on the taskbar, or maximized to take up the whole screen.
· World Wide Web, A system for exploring the Internet by using hyperlinks. When you use a Web browser, the Web appears as a collection of text, pictures, sounds, and digital movies.
· WYSIWYG, (What-You-See-Is-What-You-Get), A design philosophy for word processing programs in which formatting commands directly affect the text displayed on-screen, so that the screen shows the appearance of the printed text.
9.11 TIPS AND TRICKS
· Deleted files and folder are stored in the Recycle Bin.
· Even if you don’t Shut down your computer at the right moment, you can turn off your monitor to save power.
· The Turn off commands on the Start menu enables you to safely boot off your computer system to avoid lose of information.
· The underlined letters in menu are shortcut commands, press ALT + the underlined letter to choose the item in the menu.
· To learn what any toolbar is for, you can rest your mouse on the button of an item for a few seconds.
· To open a document quickly you can double click its icon or filename.
· To print a document quickly, you can drag its icon into a Printer icon.
· To select more than one file or folder, hold down CTRL while your click each item.
· To set your Computer Clock, you can double-click the clock on the taskbar
· When a folder is open, you can press BACKSPACE to open the folder one level higher.
· When you print a document a printer icon appears on the taskbar, double-click it to see a list of document waiting to be printed.
· When you type, you should keep your wrists elevated or use a wrist pad to minimize strain.
· You can change your Screen Saver, use your right mouse button to click the desktop, then click properties.
· You can free up disk space, by emptying the Recycle Bin.
· You can minimize all open windows at once, just use your right mouse button to click an empty area on the taskbar and the click Minimize All Window.
· You can minimize neck strain by positioning your monitor to your eye level.
· You can switch mouse buttons if you are left-handed, just double-click the mouse icon in Control Panel.
· You can use BACKUP, in the system tools folder, to make backup copies of important files.
· You can use long filenames when you save documents, you can even use spaces.
· You can use Paint in the Accessories folder to draw picture and to view bitmap files.
· You can use ScanDisk, in the system tools folder, to check you hard disk for errors.
· You can use Windows Explorer to see all files in your computer.
When you turn on your computer system, it's nice to think that you're in control. There's the trusty computer mouse, which you can move anywhere on the screen, summoning up your music library or Internet browser at the slightest whim. Although it's easy to feel like a director or a manager in front of your desktop or laptop console, there's a lot going on inside, and the real man behind the curtain handling the necessary tasks is the operating system. Operating system to any computer is the house keep and the brain behind every operations.
Most desktop or laptop PCs come pre-loaded with Microsoft Windows operating. Macintosh computers come pre-loaded with Mac OS X. Many corporate servers use the Linux or UNIX operating systems. The operating system (OS) is the first thing loaded onto the computer -- without the operating system, a computer is useless.
More recently, operating systems have started to pop up in smaller computers as well. If you like to tinker with electronic devices, you're probably pleased that operating systems can now be found on many of the devices we use every day, from cell phones to wireless access points. The computers used in these little devices have gotten so powerful that they can now actually run an operating system and applications. The computer in a typical modern cell phone is now more powerful than a desktop computer from 20 years ago, so this progression makes sense and is a natural development.
The purpose of an operating system is to organize and control hardware and software so that the device it lives in behaves in a flexible but predictable way. In this lesson, we'll tell you what a piece of software must do to be called an operating system, show you how the operating system in your desktop computer works and give you some examples of how to take control of the other operating systems around you.
1.1.1 Objective of the Lesson
At the end of this lesson, you would be able to:
· The Definition of Operating System
· Explain the term computer operating system
· Types of operating System
· Functions of Operating System
· Computer Operating System
· Know Some computer terminologies
1.2 What is Operating System?
An operating system (OS) is a set of system software programs in a computer that regulate the ways application software programs use the computer hardware and the ways that users control the computer system. For hardware functions such as input/output and memory space allocation, operating system programs act as an intermediary between application programs and the computer hardware and the user.
Because early computers were built to perform a series of single tasks, like a calculator, operating systems did not exist in their modern and more complex forms until the early 1960s. Some operating system features were developed in the 1950s, such as programs that could automatically run different programs in succession to speed up processing. Hardware features were added that enabled use of runtime libraries, interrupt, and parallel processing. When personal computers by companies such as Apple Inc., Atari, IBM and Amiga became popular in the 1980s, vendors adding operating system features that had previously become widely used on mainframe and mini computers. Later many features such as graphical user interface were developed specifically for personal computer operating systems.
An operating system can be divided into many different parts. One of the most important parts is the kernel, which controls low-level processes that the average user usually cannot see: it controls how memory is read and written, the order in which processes are executed, how information is received and sent by devices like the monitor, keyboard and mouse, and deciding how to interpret information received by networks. The user interface is the part of the operating system that interacts with the computer user directly, allowing them to control and use programs. The user interface may be graphical with icons and a desktop, or textual, with a command line. Another similar feature is an Application programming interface, which is a set of services and code libraries that let applications interact with one another, as well as the operating system itself. Depending on the operating system, many of these components may not be considered an actual part. For example, Windows considers its user interface to be part of the operating system, while many versions of Linux do not.
1.2 Types of operating System
We all know that the operating system is the most important software running on your computer without which one cannot run even the application software's which are designed to communicate with the hardware through the operating system. Are you aware that there are many types of operating systems available in the market to suit various needs and machines?
The types of the operating systems can be classified as single user program and multi tasking. A single user program operating system allows only one program to run at a time. This was the operating system that was improved on to as multi-tasking operating systems as it was not practical to close one application to open another, example, close a word document to open power point, especially if you are required to copy some texts from Microsoft word to Microsoft power point.
· Multi tasking operating systems enables a single user to have two or more applications open at the same time. It gives the computer the option to decide on how many time slices each program is allocated. The active program gets the most, and the rest is divided according to the factors of which programs are doing tasks although not active, and the last priority is given to programs and applications that are left open but are not doing anything.
· Multi tasking operating systems can be divided into three general types depending on the type of computer and the type of applications that will be run. These are Real time operating systems, Single user-Multi tasking, Multi user operating systems
· Real time operating systems (RTOS) are mainly used to control machinery, scientific instruments, industrial systems, etc. Here the user does not have much control over the functions performed by the RTOS.
· Single user, multi tasking operating systems are the systems that allow a single user to run different applications at the same time. Windows of Microsoft and Macintosh of Apple are the most commonly used single user, multi tasking operating systems.
· Multi user operating systems give access at the same time to the resources on a single computer to many users. Unix is one such operating system.
The most commonly used operating systems that fall under the above categories are, Windows 95, Windows 98, Windows Me, Windows NT, Windows 2000, Windows XP (Which is an upgrade of all the earlier and comes in two versions as Home and Professional. The professional version is the same as the home edition but has additional features, like networking and security features.), Windows Vista, Windows CE, Apple Macintosh, Unix, etc.
1.4 Functions of Operating System
Today most operating systems perform the following important functions:
· Processor management, that is, assignment of processor to different tasks being performed by the computer system.
· Memory management, that is, allocation of main memory and other storage areas to the system programmes as well as user programmes and data.
· Input/output management, that is, co-ordination and assignment of the different output and input device while one or more programmes are being executed.
· File management, that is, the storage of file of various storage devices to another.
· It also allows all files to be easily changed and modified through the use of text editors or some other files manipulation routines.
· Establishment and enforcement of a priority system. That is, it determines and maintains the order in which jobs are to be executed in the computer system.
· Automatic transition from job to job as directed by special control statements.
· Interpretation of commands and instructions.
· Coordination and assignment of compilers, assemblers, utility programs, and other software to the various user of the computer system.
· Facilities easy communication between the computer system and the computer operator (human). It also establishes data security and integrity.
1.5 names of some Computer Operating System
Microsoft Windows, Mac OS X, Linux, FreeBSD, NetBSD, OpenBSD, MS-DOS, FreeDOS, AmigaOS, BeOS, MorphOS, QNX, OS4000, VxWorks, ReactOS, DR-DOS, Solaris, TOS, GEM, NetWare, OpenVMS, Syllable, Haiku, AROS, MenuetOS, KolibriOS, LynuxWorks, Multics, System/360, Unix
3.36 COMPUTER GLOSSARY
· Access Memory (RAM): Memory that can be read from or written to by a computer or other devices. Information stored in RAM is lost when the computer is turned off.
· Active Directory, The directory service that stores information about objects on a network and makes this information available to users and network administrators. Active Directory gives network users access to permitted resources anywhere on the network using a single logon process. It provides network administrators with an intuitive, hierarchical view of the network and a single point of administration for all network objects.
· Active, Describes the window or icon that you are currently using or that is currently selected. The operating system always applies the next keystroke or command you choose to the active window. Windows or icons on the desktop that are not selected are inactive.
· Background, The screen background image used on a graphical user interface such as Windows. Any pattern or picture that can be stored as a bitmap (.bmp) file can be set as a screen background.
· Bit, The basic unit of information in a binary numbering system. Computer work with binary numbers, and the internal circuit can represent one of the two numbers in a binary system 1 or 0. This basic either/or, yes/no units of information are called bits.
· Boot, The process of starting or resetting a computer. When first turned on (cold boot) or reset (warm boot), the computer runs the software that loads and starts the computer's operating system, which prepares it for use. Booting initiate automatic routine that clears the memory loads the operating system, and prepares the computer for use. The term boot is derived form saying "pulling yourself up by your own bootstraps" personal computers must just do that because Random Access Memory (RAM) does not retain program instruction which the power is shut off.
· Byte, Pronounced "bite" eight contiguous bits, the fundamental data word of personal computers. It provides a basic unit of measurement for computer storage.
· CD-R: Recordable compact disc. Data can be copied to the CD on more than one occasion; however, data cannot be erased from the CD.
· CD-RW, Rewritable compact disc. Data can be copied to the CD on more than one occasion and can be erased.
· Chips, A miniaturized electronic circuit mass produced on a tiny chip or wafer of silicon.
· Commands, A user uninitiated signal given to a computer to controls the execution of a specific operation.
· Cursor, An on-screen-blinking character that show where next operation will take place.
· Default printer, The printer to which a computer sends documents if you select the Print command without first specifying which printer you want to use with a program. You can have only one default printer; it should be the printer you use most often.
· Desktop, The on-screen work area on which windows, icons, menus, and dialog boxes appear.
· Device driver, A program that allows a specific device, such as a modem, network adapter, or printer, to communicate with the operating system. Although a device might be installed on your system, Windows cannot use the device until you have installed and configured the appropriate driver. If a device is listed in the Hardware Compatibility List (HCL), a driver is usually included with Windows. Device drivers load automatically (for all enabled devices) when a computer is started, and thereafter run invisibly.
· Device, Any piece of equipment that can be attached to a network or computer; for example, a computer, printer, joystick, adapter, or modem card, or any other peripheral equipment. Devices normally require a device driver to function with Windows.
· Dialog box, A secondary window that contains buttons and various kinds of options through which you can carry out a particular command or task.
· Digital video disc (DVD), A type of optical disc storage technology. A digital video disc (DVD) looks like a CD-ROM disc, but it can store greater amounts of data. DVDs are often used to store full-length movies and other multimedia content that requires large amounts of storage space.
· Disk, A storage device that is attached to a computer.
· Document, Any self-contained piece of work created with an application program and, if saved on disk, given a unique file name by which it can be retrieved.
· Drag, To move an item on the screen by selecting the item and then pressing and holding down the mouse button while moving the mouse. For example, you can move a window to another location on the screen by dragging its title bar.
· Drive letter, The naming convention for disk drives on IBM and compatible computers. Drives are named by letter, beginning with A, followed by a colon.
· Drive, An area of storage that is formatted with a file system and has a drive letter. The storage can be a floppy disk, a CD, a hard disk, or another type of disk. You can view the contents of a drive by clicking its icon in Windows Explorer or My Computer.
· DVD drive, A disk storage device that uses digital video disc (DVD) technology. A DVD drive reads both CD-ROM and DVDs; however, you must have a DVD decoder to display DVD movies on your computer screen.
· Expansion slot, A socket in a computer, designed to hold expansion boards and connect them to the system bus.
· Filename, A name assigned to a file (document) so that the operating system can find the file. You assign file names when the file is created. Every file on a disk must have a unique name.
· Folder, A container for programs and files in graphical user interfaces, symbolized on the screen by a graphical image (icon) of a file folder. A folder is a means of organizing programs and documents on a disk and can hold both files and additional folders.
· Font; A graphic design applied to a collection of numbers, symbols, and characters. A font describes a certain typeface, along with other qualities such as size, spacing, and pitch.
· Gigabyte (GB), 1,024 megabytes, though often interpreted as approximately one billion bytes.
· GIGO, (Garbage In, Garbage Out), This means that the output you get from the system depends directly on what you key-in as your inputs.
· Hard disk, A device, also called hard disk drive, that contains one or more inflexible platters coated with material in which data can be recorded magnetically with read/write heads. The hard disk exists in a sealed case that protects it and allows the head to fly 10 millionths to 25 millionths of an inch above the surface of a platter. Data can both be stored and accessed much more quickly than on a floppy disk.
· Hardcopy, Printed output from the system distinguished from data stored on disk or in memory.
· Hardware, The physical components of a computer system, including any peripheral equipment such as printers, modems, and mouse devices.
· Icon, A small image displayed on the screen to represent an object that can be manipulated by the user. Icons serve as visual mnemonics and allow the user to control certain computer actions without having to remember commands or type them at the keyboard.
· Input/output (I/O) port, A channel through which data is transferred between a device and the microprocessor. The port appears to the microprocessor as one or more memory addresses that it can use to send or receive data.
· Insertion point, The place where text will be inserted when typed. The insertion point usually appears as a flashing vertical bar in an application's window or in a dialog box.
· Install, When referring to software, to add program files and folders to your hard disk and related data to your registry so that the software runs properly. Installing contrasts with upgrading, where existing program files, folders, and registry entries are updated to a more recent version.
· Internet, A worldwide network of computers. If you have access to the Internet, you can retrieve information from millions of sources, including schools, governments, businesses, and individuals.
· Kilobyte, The basic unit of measurement for computer memory equal to 1,024 bytes.
· Maximize, To enlarge a window to its largest size by clicking the Maximize button (at the right of the title bar), or by pressing ALT+SPACEBAR and then pressing X.
· Media, Any fixed or removable objects that store computer data. Examples include hard disks, floppy disks, tapes, and compact discs.
· Minimize, To reduce a window to a button on the taskbar by clicking the Minimize button (at the right of the title bar), or by pressing ALT+SPACEBAR and then pressing N.
· Monitor, The complete device that produces an on-screen display, including all necessary internal support circuiting. A monitor is also called a Video Display Unit (VDU) or cathode-rye tube (CRT).
· My Documents, A folder that provides you with a convenient place to store documents, graphics, or other files you want to access quickly. When you save a file in a program such as WordPad or Paint, the file is automatically saved in My Documents, unless you choose a different folder.
· Network, A group of computers and other devices, such as printers and scanners, connected by a communications link, enabling all the devices to interact with each other. Networks can be small or large, permanently connected through wires or cables, or temporarily connected through phone lines or wireless transmissions. The largest network is the Internet, which is a worldwide group of networks.
· Operating System; Is a group of program that act as a translator between you, the operator, and your computer system. It is the program that controls the processing of information in the computer. In all, it's regulates the operation of the computer system. Operating system is the Brian behind the computer operations. It is also known as a master control program in the computer system.
· OS/2, A protected-mode, virtual memory, multitasking operating system for personal computers based on the Intel 80286, 80386, i486, and Pentium processors. OS/2 can run most MS-DOS-based programs and can read all MS-DOS disks.
· Output Unit, The component of the computer system that takes care of displaying or printing the results of processing operation.
· Peripheral, A device, such as a disk drive, printer, modem, or joystick, that is connected to a computer and is controlled by the computer's microprocessor.
· Printer, A device that puts text or images on paper or other print media. Examples are laser printers or dot-matrix printers.
· Program, A complete, self-contained set of computer instructions that you use to perform a specific task, such as word processing, accounting, or data management. Program is also called application. A list of instruction in a computer programming language that tells the computer what to do.
· Random access memory (RAM), Memory that can be read from or written to by a computer or other devices. Information stored in RAM is lost when the computer is turned off.
· Recycle Bin, The place in which Windows stores deleted files. You can retrieve files you deleted in error, or you can empty the Recycle Bin to create more disk space.
· ROM, An acronym for Read-Only Memory, a semiconductor circuit into which code or data is permanently installed by the manufacturing process. ROM contains instructions or data that can be read but not modified
· Screen saver, A moving picture or pattern that appears on your screen when you have not used the mouse or keyboard for a specified period of time.
· Select, To specify a block of data or text on screen by highlighting it or otherwise marking it, with the intent of performing some operation on it.
· Serial port, An interface on the computer that allows asynchronous transmission of data characters one bit at a time. Also called a communication or COM port.
· Server, In general, a computer that provides shared resources to network users.
· Shortcut, A link to any item accessible on your computer or on a network, such as a program, file, folder, disk drive, Web page, printer, or another computer. You can put shortcuts in various areas, such as on the desktop, on the Start menu, or in specific folders.
· System disk, A disk that contains the MS-DOS system files necessary to start MS-DOS.
· System files, Files used by Windows to load, configure, and run the operating system. Generally, system files must never be deleted or moved.
· Taskbar button, A button that appears on the taskbar and corresponds to a running application.
· Taskbar, The bar that contains the Start button and appears by default at the bottom of the desktop. You can click the taskbar buttons to switch between programs. You can also hide the taskbar, move it to the sides or top of the desktop, and customize it in other ways.
· Terminal, A device consisting of a display screen and a keyboard that is used to communicate with a computer.
· Text box, In a dialog box, a box in which you type information needed to carry out a command. The text box may be blank or may contain text when the dialog box opens.
· Thumbnail, A miniature version of an image that is often used for quick browsing through multiple images.
· Title bar, The horizontal bar at the top of a window that contains the name of the window. On many windows, the title bar also contains the program icon, the Maximize, Minimize, and Close buttons, and the optional button for context-sensitive Help. To display a menu with commands such as Restore and Move, right-click the title bar.
· ToggleKeys, A feature that sets your keyboard to beep when one of the locking keys (CAPS LOCK, NUM LOCK, or SCROLL LOCK) is turned on or off.
· Toolbar, In a program in a graphical user interface, a row, column, or block of on-screen buttons or icons. When clicked, these buttons or icons activate certain functions, or tasks, of the program. For example, the toolbar in Microsoft Word contains buttons for, among other actions, changing text to italic or boldface, and for saving or opening a document. Users can often customize toolbars and move them around on the screen.
· Tree view, A hierarchical representation of the folders, files, disk drives, and other resources connected to a computer or network. For example, Windows Explorer uses a tree view to display the resources that are attached to a computer or a network.
· Uninstall: When referring to software, the act of removing program files and folders from your hard disk and removing related data from your registry so the software is no longer available. When referring to a device, the act of removing the corresponding device drivers from your hard disk and physically removing the device from your computer.
· UNIX, A powerful, multiuser, multitasking operating system initially developed at AT&T Bell Laboratories in 1969 for use on minicomputers. UNIX is considered more portable, that is, less computer-specific, than other operating systems because it is written in C language. Newer versions of UNIX have been developed at the University of California at Berkeley and by AT&T
· Unix; A powerful, multiuser, multitasking operating system initially developed at AT&T Bell Laboratories in 1969 for use on minicomputers. UNIX is considered more portable, that is, less computer-specific, than other operating systems because it is written in C language. Newer versions of UNIX have been developed at the University of California at Berkeley and by AT&T.
· USB port, An interface on the computer that enables you to connect a Universal Serial Bus (USB) device. USB is an external bus standard that enables data transfer rates of 12 Mbps (12 million bits per second). USB ports support a plug that is approximately 7 mm x 1 mm.
· User, A person who uses a computer. If the computer is connected to a network, a user can access the programs and files on the computer, as well as programs and files located on the network (depending on account restrictions determined by the network administrator).
· Video adapter, An expansion board that plugs into a personal computer to give it display capabilities. A computer's display capabilities depend on both the logical circuitry (provided in the video adapter) and the monitor. Each adapter offers several different video modes. The two basic categories of video modes are text and graphics. Within the text and graphics modes, some monitors also offer a choice of resolutions. At lower resolutions a monitor can display more colors. Modern adapters contain memory, so that the computer's RAM is not used for storing displays. In addition, most adapters have their own graphics coprocessor for performing graphics calculations. These adapters are often called graphics accelerators.
· Virus, A program that attempts to spread from computer to computer and either cause damage (by erasing or corrupting data) or annoy users (by printing messages or altering what is displayed on the screen).
· Wildcard character, A keyboard character that can be used to represent one or many characters when conducting a query. The question mark (?) represents a single character, and the asterisk (*) represents one or more characters.
· Window, A portion of the screen where programs and processes can be run. You can open several windows at the same time. For example, you can open your e-mail in one window, work on a budget in a spreadsheet in another, download pictures from your digital camera in another window, and order your weekly groceries on the Web in another window. Windows can be closed, resized, moved, minimized to a button on the taskbar, or maximized to take up the whole screen.
· World Wide Web, A system for exploring the Internet by using hyperlinks. When you use a Web browser, the Web appears as a collection of text, pictures, sounds, and digital movies.
· WYSIWYG, (What-You-See-Is-What-You-Get), A design philosophy for word processing programs in which formatting commands directly affect the text displayed on-screen, so that the screen shows the appearance of the printed text.
9.11 TIPS AND TRICKS
· Deleted files and folder are stored in the Recycle Bin.
· Even if you don’t Shut down your computer at the right moment, you can turn off your monitor to save power.
· The Turn off commands on the Start menu enables you to safely boot off your computer system to avoid lose of information.
· The underlined letters in menu are shortcut commands, press ALT + the underlined letter to choose the item in the menu.
· To learn what any toolbar is for, you can rest your mouse on the button of an item for a few seconds.
· To open a document quickly you can double click its icon or filename.
· To print a document quickly, you can drag its icon into a Printer icon.
· To select more than one file or folder, hold down CTRL while your click each item.
· To set your Computer Clock, you can double-click the clock on the taskbar
· When a folder is open, you can press BACKSPACE to open the folder one level higher.
· When you print a document a printer icon appears on the taskbar, double-click it to see a list of document waiting to be printed.
· When you type, you should keep your wrists elevated or use a wrist pad to minimize strain.
· You can change your Screen Saver, use your right mouse button to click the desktop, then click properties.
· You can free up disk space, by emptying the Recycle Bin.
· You can minimize all open windows at once, just use your right mouse button to click an empty area on the taskbar and the click Minimize All Window.
· You can minimize neck strain by positioning your monitor to your eye level.
· You can switch mouse buttons if you are left-handed, just double-click the mouse icon in Control Panel.
· You can use BACKUP, in the system tools folder, to make backup copies of important files.
· You can use long filenames when you save documents, you can even use spaces.
· You can use Paint in the Accessories folder to draw picture and to view bitmap files.
· You can use ScanDisk, in the system tools folder, to check you hard disk for errors.
· You can use Windows Explorer to see all files in your computer.
No comments:
Post a Comment