Operating System Functions
An operating system performs five basic functions in the operation of a computer system: providing a user interface, resource management, task management, file management, and utilities and support services.
The User Interface. The user interface is the part of the operating system that allows you to communicate with it so you can load program , access files, and accomplish other tasks. Three main types of user interfaces are the command driven, menu driven, and graphical user interfaces. The trend in user interfaces for operating systems and other software is moving away from the entry of brief end user commands, or even the selection of choices from menus of options. Instead, the trend is toward an easy-to-use graphical user interface (GUI) that uses icons, bars, buttons, boxes, and other images. GUIs rely on pointing devices like the electronic mouse or trackball to make selections that help you get things done.
Resource Management. An operating system uses a variety of resource management programs to manage the hardware and networking resources of a computer system, including is CPU, memory, secondary storage devices, telecommunications processors, and input/output peripherals, For example, memory management programs keep track of where data and programs are stored. They may also subdivide memory into a number of sections and swap parts of programs and data between memory and magnetic disks or other secondary storage devices. This can provide a computer system with a virtual memory capability that is significantly larger than the real memory capacity of its primary storage unit. So a computer with a virtual memory capability can process larger programs and greater amounts of data than the capacity of its memory circuits would normally allow.
File Management. An operating system contains file management programs that control the creation, deletion, and access of files of data and programs. File management also involves keeping track of the physical location of files on magnetic disks and other secondary storage devices. So operating systems maintain directories of information about the location and characteristics of files stored on a computer system’s secondary storage-devices.
Task Management. The task management programs of an operating system manage the accomplishment of the computing tasks of end users. They give each task a slice of a CPU’s time and interrupt the CPU operations to substitute other tasks. Task management may involve a multitasking capability where several computing tasks can occur at the same time. Multitasking may take the form of multiprogramming, where the CPU can process the tasks of several programs at the same time, or time sharing, where the computing tasks of several users can be processed at the same time. The efficiency of multitasking operations depends on the processing power of a CPU and the virtual memory and multitasking capabilities of the operating system it uses.
New microcomputer operating systems and most midrange and mainframe operating systems provide a multitasking capability. With multitasking, end users can do two or more operations (e.g., keyboarding and printing) or applications (e.g., word processing and financial analysis) concurrently, that is, at the same time. Multitasking on microcomputers has also been made possible by the development of more powerful microprocessors (like the Intel Pentium-II) and their ability to directly address much larger memory capacities (upto 4 gigabytes). This allows an operating system to subdivide primary storage into several large partitions, each of which can be used by a different application program.
In effect, a single computer can act as if it were several computers, or virtual machines, since each application program is running independently at the same time. The number of programs that can be run concurrently depends on the amount of memory that is available and the amount of processing each job demands. That’s because a microprocessor (or CPU) can become overloaded with too many jobs and provide unacceptably slow response times. However, if memory and processing capacities are adequate, multitasking allows end users to easily switch from one application to another, share data files among applications, and process some applications in a background mode typically, background tasks include large printing jobs, extensive mathematical computation, or unattended telecommunications sessions.
An operating system performs five basic functions in the operation of a computer system: providing a user interface, resource management, task management, file management, and utilities and support services.
The User Interface. The user interface is the part of the operating system that allows you to communicate with it so you can load program , access files, and accomplish other tasks. Three main types of user interfaces are the command driven, menu driven, and graphical user interfaces. The trend in user interfaces for operating systems and other software is moving away from the entry of brief end user commands, or even the selection of choices from menus of options. Instead, the trend is toward an easy-to-use graphical user interface (GUI) that uses icons, bars, buttons, boxes, and other images. GUIs rely on pointing devices like the electronic mouse or trackball to make selections that help you get things done.
Resource Management. An operating system uses a variety of resource management programs to manage the hardware and networking resources of a computer system, including is CPU, memory, secondary storage devices, telecommunications processors, and input/output peripherals, For example, memory management programs keep track of where data and programs are stored. They may also subdivide memory into a number of sections and swap parts of programs and data between memory and magnetic disks or other secondary storage devices. This can provide a computer system with a virtual memory capability that is significantly larger than the real memory capacity of its primary storage unit. So a computer with a virtual memory capability can process larger programs and greater amounts of data than the capacity of its memory circuits would normally allow.
File Management. An operating system contains file management programs that control the creation, deletion, and access of files of data and programs. File management also involves keeping track of the physical location of files on magnetic disks and other secondary storage devices. So operating systems maintain directories of information about the location and characteristics of files stored on a computer system’s secondary storage-devices.
Task Management. The task management programs of an operating system manage the accomplishment of the computing tasks of end users. They give each task a slice of a CPU’s time and interrupt the CPU operations to substitute other tasks. Task management may involve a multitasking capability where several computing tasks can occur at the same time. Multitasking may take the form of multiprogramming, where the CPU can process the tasks of several programs at the same time, or time sharing, where the computing tasks of several users can be processed at the same time. The efficiency of multitasking operations depends on the processing power of a CPU and the virtual memory and multitasking capabilities of the operating system it uses.
New microcomputer operating systems and most midrange and mainframe operating systems provide a multitasking capability. With multitasking, end users can do two or more operations (e.g., keyboarding and printing) or applications (e.g., word processing and financial analysis) concurrently, that is, at the same time. Multitasking on microcomputers has also been made possible by the development of more powerful microprocessors (like the Intel Pentium-II) and their ability to directly address much larger memory capacities (upto 4 gigabytes). This allows an operating system to subdivide primary storage into several large partitions, each of which can be used by a different application program.
In effect, a single computer can act as if it were several computers, or virtual machines, since each application program is running independently at the same time. The number of programs that can be run concurrently depends on the amount of memory that is available and the amount of processing each job demands. That’s because a microprocessor (or CPU) can become overloaded with too many jobs and provide unacceptably slow response times. However, if memory and processing capacities are adequate, multitasking allows end users to easily switch from one application to another, share data files among applications, and process some applications in a background mode typically, background tasks include large printing jobs, extensive mathematical computation, or unattended telecommunications sessions.
