operating system Last modified: Friday, January 04, 2002
The most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop -- it makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system. 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. As a user, you normally interact with the operating system through a set of commands. For example, the DOS operating system contains commands such as COPY and RENAME for copying files and changing the names of files, respectively. The commands are accepted and executed by a part of the operating system called the command processor or command line interpreter. Graphical user interfaces allow you to enter commands by pointing and clicking at objects that appear on the screen.
•E-mail this definition to a colleague• Sponsored listings Data Backup Services - Provides eSureIT, an online backup service, for home and business. Free 30-day trial; $9.95/month for 1GB. Unix Hosting - Offers a Web hosting directory and rating system that enables customers to select a Web hosting company based on features, price and more. Data Backup Services - LogMeIn Backup provides automated and secure data backup to devices you control. For internet.com pages about operating system . Also check out the following links! DOS concepts and functions  This page is for novice computer users and provides a short introduction to computers and basic functions of an operating system. A table of contents then provides links to specific DOS concepts and functions. Virtual Doctor  Using the Virtual Doctor, users can acquire help with a specific problem, download software, grab updates for their operating system or receive expert tutorials catering to their specific needs. ACM SIG Operating Systems Addresses a broad spectrum of issues associated with operating systems research and development. CMX-RTX real time operating system Product feature page for the CMS-RTX real time multitasking operating system for microprocessors and microcomputers. OS News On-line magazine covering alternative operating systems and computing environments. osOpinion Daily computer and operating system news and opinion commentary. Real-Time and RTOS Computing Resources List of sites related to real time operating systems and programming. RTMX operating system information page Provides product information for the RTMX real time operating system, including features and supported CPU types. In addition, there are links to related real time computing Web sites. Yahoo!'s operating systems page Yahoo!'s directory of links to operating systems. Yahoo!'s OS/2 operating system page Yahoo!'s directory of the OS/2 operating system. Yahoo!'s real time systems page Yahoo!'s directory of real time systems. Yahoo!'s UNIX page Yahoo!'s directory of UNIX operating systems links. Sponsored listings Sun Server Bundles - Save 15% on a Server/Storage Bundle. Limited Time Only. Learn More Now. Unix Hosting - Visit Tophosts.com and view the top 25 Unix Hosting providers. Read reviews/articles and use FastFind package wizard. Windows Managed Hosting, Managed Security and SAN storage - High performance Managed Hosting plans with personal 24x7 technical support. Managed Firewalls and Managed Backups on the Rock-solid PEER 1 network.	Operating Systems abort application BeOS BIOS command processor DOS fatal exception error file management system flat file system kernel kernel32.dll Mac OS Microsoft Windows multiprocessing multitasking multithreading multi-user MVS NTLDR OS/2 PXE UNIX VMS Windows 2000 Windows CE Give Us Your Feedback operating system Products : Top Store Offers: Software Media.com  887.75The MSDN Operating Systems Subscription includes:Windows Vista Ultimate / Enterprise / Business / Home Premium / Home BasicWindows XP Professional/Ho... Amazon  346.80CA, Platforms: No Operating System Avanquest Software  69.95Safely & Securely Run Multiple Operating Systems on Your PC! Safely partition, install and run multiple operating systems on one computer. When bootin... Ubid.com  55.00Software - National Geographic Back Road Explorer 3D: software discount software cheap software computer software buy software educational software ac... Software Media.com  1027.10MSDN Operating Systems 32bit License with Software AssuranceAn MSDN Operating Systems Subscription provides access to the latest Microsoft operating s... Compare all matches: 242 Store Offers