What is an Operating System? An Operating System is the most important software that runs on a computer. It manages the computers memory, processes, and all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computers language. Without an operating system, a computer is useless. The Operating Systems job Youve probably heard the phrase boot your computer, but do you know what that means? Booting is the process that occurs when you press the power button to turn your computer on. During this process (which may take a minute or two), the computer does several things: • It runs tests to make sure everything is working correctly. • It checks for new hardware. • It then starts up the operating system. Once the operating system has started up, it manages all of the software and hardware on the computer. Most of the time, there are many different programs running at the same time, and they all need to access your computers central processing unit (CPU), memory, and storage. The operating system coordinates all of this to make sure each program gets what it needs. Without the operating system, the software wouldnt even be able to talk to the hardware, and the computer would be useless. In the image below, you can see how Windows 7 appears after starting up. Operating systems can be classified as follows: • Multi-user: Allows two or more users to run programs at the same time. Some operating systems permit hundreds or even thousands of concurrent users. • Multiprocessing : Supports running a program on more than one CPU. • Multitasking : Allows more than one program to run concurrently. • Multithreading : Allows different parts of a single program to run concurrently. • Real time: Responds to input instantly. General-purpose operating systems, such as DOS and UNIX, are not real-time. Operating systems provide a software platform on top of which other programs, called application programs, can run. The application programs must be written to run on top of a particular operating system. Your choice of operating system, therefore, determines to a great extent the applications you can run. For PCs, the most popular operating systems are DOS, OS/2, and Windows, but others are available, such as Linux. An operating system is a special piece of software that manages the general operation of a computer system: • It provides a user interface so that we can interact with the computer • It manages applications that are running on the computer, starting them when the user requests, and stopping them when they are no longer needed • It manages files, helping us save our work, organize our files, find files that we have saved and load files • It manages the computer’s memory, deciding what should be loaded into memory and what should be removed • It looks after computer security, preventing unauthorized access to the system • It manages the computer’s input and output hardware such as printers, etc. The Operating System (OS) is the software responsible for managing the usage of hardware resource such as: • Memory • Central processing Unit Time • Disk drive space • Peripherals Functions performed by the Operating System Starting the computer Managing the peripherals Administering application programs Store and recall functions Utility functions Programming Tools Communication of the User and Machine Boot Strapping is the Computer for use is performed in a procedure called Booting. Kinds of Booting: Warm Boot – Pressing of the Reset Button. Cold Boot – On / Off the switch or off / on of the switch. Basic Operating System Concept Process – A program in Execution. Interrupts – refers to the signals from the Input – Output devices, that indicate the transfer of data from a program. History of Operating System according to versions 1975–1981: Microsoft boots up 1980 MS DOS 1982–1985: Introducing Windows 1.0 1987–1990: Windows 2.0–2.11 1990: Windows 3.0 1993: Windows NT 1995: Windows 95—the PC comes of age (and dont forget the Internet) 1998 - Windows 98 2000 - Windows Me (Millennium Edition/ Media Experience) 2000 - Windows 2000 Professional19 2001 - Windows XP 2006 - Windows Vista 2009 - Windows 7 2012 - Windows 8 Reviewer :)
Posted on: Sun, 31 Aug 2014 11:26:58 +0000
Trending Topics
Recently Viewed Topics
© 2015