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Operating system overview


An operating system (abbreviated OS) is a type of system software that acts as a mast controller for all the activities that take place within a computer system. It is one of the factors that determine your computer compatibilityand platform. The operating system interactswith application software, device drivers, and hardware to manage a computer’s resources. The term resource refers to any component that is required to perform work. For example, the processor is a resource. RAM, storage space, and peripherals are also resources.

Operating system manages different tasks:

- Managememory. OS allocates a specific area of RAM for each program that is open and running. OS is itself a program, so it requires RAM space too. A microprocessor works with data and executes instructions stored in RAM – one of your computer’s most important resources. When you want to run more than one program at a time, the OS has to allocate specific areas of memory for each program. When multiple programs are running, the OS must ensurethat instructions and data from one area of memory do not “leak” into an area allocated to another program. If an OS falls down on the job and fails to protect each program’s memory area, data can get corrupted, programs can “crash”, and your computer displays error messages.

- Manage processor resources. The operating system also controls the microprocessor – just at a slightly higher level. Every cycle of a computer’s microprocessor is a resource for accomplishing tasks. Many activities – called “processes” – compete for the attention of your computer’s microprocessor. OS must ensure that each activity “process” receives its share of microprocessor cycles. A computer can take advantage of performance-enhancing technologies such as multitasking,multithreading, multiprocessing,dual coreormultiple processors.

- Keep track of storage resources. OS stores and retrieves files from your disks and CDs. It remembers the names and locations of all your files and keeps track of empty spaces where new files can be stored.

- Ensure that input and output proceed in an orderly manner. OS communicates with device driver software so that data can travel smoothly between the computer and these peripheral resources. OS uses ‘buffers’ to collect and hold data while the computer is busy with other tasks.

- Establish basic elements of the user interface. A user interface can be definedas the combination of hardware and software that helps people and computers communicate with each other. Your computer’s user interface includes a display device, mouse, and keyboard that allow you to view and manipulate your computer environment. It also includes software elements, such as menus and toolbar buttons. A graphical user interface (GUI)features menus and icons that you can manipulate with the click of a mouse. A command-line interface requires you to memorize and type commands.

For nearly all PCs, servers, workstations, mainframes, and supercomputers, the operating system program is quite large, so most of it is stored on a hard disk. The operating system’s small bootstrap program is stored in ROM and supplies the instructions needed to load the operating system’s core into memory when the system boots. This core part of OS called the kernelprovides the most essential operating system services, such as memory management and file access. The kernel always stays in RAM all the time your computer is on. Other parts of OS, such as customization utilities, are loaded into RAM as they are needed.

Many operating systems provide helpful tools, called operating system utilities, that you can use to control and customize your computer equipment and work environment. They are typically accessed by using a GUI, such as the familiar Windows desktop. The most popular are: launch programs, manage files, get help, customize the user interface, and configure equipment.

One operating system might be better suited to some computing tasks than others. To provide clues to their strengths and weaknesses, operating systems are informally categorized using one or more of the following terms:

A single-user operating system expects to deal with one set of input devices – those that can be controlled by one user only.

A multiuser operating systemallows a single computer to deal with simultaneousinput, output, and processing requests from many users. One of its most difficult responsibilities is to schedule all the processing requests that a centralized computer must perform.

A network operating system provides communications and routing services that allow computers to share data, programs, and peripheral devices. The main difference between network OS and multiuser OS is that multiuser operating systems schedule requests for processing on a centralized computer, whereas a network operating system simply routes data and programs to each user’s local computer, where the actual processing takes place.

A desktop operating system is one that is designed for a personal computer. Typically, these operating systems are designed to accommodate a single user, but might also provide network capability.

Windows is the best-selling operating system. The number and variety of programs that run on Windows are unmatched by any other operating system, a fact that contributes to its dominant position as the most widely used desktop operating system.

Utility software is a type of system software that is designed to perform a specialized task, such as system maintenance or security. Utility software that does not come packaged with an operating system is often referred to as a third-party utility. In past years, antivirus software was a popular category of third-party utilities. With the recent influx of nuisance ads, intrusion attempts, and spam, utilities such as ad blockers, personal firewalls, and spam filters have also become best sellers. Filtering software is used by parents to block their children from objectionable Websites. Another popular category of utility software is system utilities. These utilities track down and fix disk errors, repair corrupted files, and give your PC a performance – enhancing tune-up.

A final group of utilities worth mentioning is designed for backing upand cleaning up hard disks, and shredding files so they can’t be recovered. They can help you recover files deleted by mistake.


Comprehension check. Indicate the paragraph where the following ideas are found in the text.

1. Operating system’s main purpose is to control what happens behind the scene.

2. Your PC can sometimes recover from memory leak problems if you use the Ctl+Alt+Del key sequence to close the corrupted program.

3. The operating system must ensure that the microprocessor does not “spin its wheels” waiting for input while it could be working on some other processing projects.

4. Windows is installed on more than 80 % of the world’s personal computers.

5. The term “buffer” is a technical jargon for a region of memory that holds data waiting to be transferred from one device to another.

6. Many operating systems provide helpful tools, called operating system utilities, that you can use to control and customize your computer equipment and work environment.

Date: 2016-01-03; view: 281

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