An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is a vital component of the system software in a computer system. Application programs usually require an operating system to function. For any computer to function, it must have an operating system (OS). A powered computer with no operating system will only display coded text messages only understandable to the computer itself as the coded text messages will only depict the booting process.
When a computer is powered, it searches for an operating system and if it doesn’t find, it will prompt the user to provide the OS. An operating system controls the way in which the computer system functions. In order to do this, the operating system includes programs that * Initialize the hardware of the computer system * Provide basic routines for device control * Provide for the management, scheduling and interaction of tasks * Maintain system integrity and handle errors 2. History: Operating systems have evolved through a number of distinct phases or generations which corresponds roughly to the decades.
The 1940’s – First Generations: The earliest electronic digital computers had no operating systems. Machines of the time were so primitive that programs were often entered one bit at time on rows of mechanical switches (plug boards). Programming languages were unknown (not even assembly languages). The 1950’s – Second Generation: By the early 1950’s, the routine had improved somewhat with the introduction of punch cards. The General Motors Research Laboratories implemented the first operating systems in early 1950’s for their IBM 701.
The system of the 50’s generally ran one job at a time. These were called single-stream batch processing systems because programs and data were submitted in groups or batches. The 1960’s – Third Generation: The systems of the 1960’s were also batch processing systems, but they were able to take better advantage of the computer’s resources by running several jobs at once. Another feature present in this generation was time-sharing technique, a variant of multiprogramming technique Fourth Generation: With he development of LSI (Large Scale Integration) circuits, chips, operating system entered in the system entered in the personal computer and the workstation age. Microprocessor technology evolved to the point that it becomes possible to build desktop computers as powerful as the mainframes of the 1970s. Two operating systems have dominated the personal computer scene: MS-DOS, written by Microsoft, Inc. for the IBM PC and other machines using the Intel 8088 CPU and its successors, and UNIX, which is dominant on the large personal computers using the Motorola 6899 CPU family. 3.
Components of Operating System: The operating system comprises a set of software packages that can be used to manage interactions with the hardware. The following elements are generally included in this set of software: The kernel, which represents the operating system’s basic functions such as management of memory, processes, files, main inputs/outputs and communication functionalities. The shell, allowing communication with the operating system via a control language, letting the user control the peripherals without knowing the characteristics of the hardware used, management of physical addresses, etc.
The file system, allowing files to be recorded in a tree structure. 4. Roles of Operating System: An operating system carries out two basic functions: (1) it serves as a manger for the hardware and software resources held in the system; and (2) it deals with hardware without the applications having to know every aspect along the way. The duties of the operating system fall into six different categories: processor management, memory management, device management, storage management, application interface and user interface.
Processor Management: Processor management involves the certainty that all applications and processes get the appropriate amount of time from the processor so that it can function properly. The operating system uses the process or thread of the processor to carry out these functions and it continuously switches between processes at the rate of thousands of processes per second. Memory Management: Memory management is the process of ensuring that each process has the amount of memory needed to execute the task so that processes do not steal memory from each other.
Another part of memory management is managing each type of memory so that it is used properly. Device Management: Every piece of hardware uses a driver, a special program, to communicate with the system. The operating system uses the drivers as a translator between the electrical signals from the hardware and the programming code found in applications. The driver takes data from the operating system to the device and vice versa. The operating system controls this process by calling on the appropriate driver when it is needed.
Application Program Interface: Just like hardware has drivers, applications have application program interfaces (APIs). APIs allow the programmers to use parts of the operating system and computer to carry out certain functions. The operating system holds all of the APIs that are recognizable to the computer and plays the role of interpreter for the APIs. It then sends the data required so that the function is carried out. User Interface: The user interface aspect of the operating system manages the interaction between the user and computer.
Many operating systems use graphical user interfaces, which mean that it uses images and icons to communicate with the user. The operating system once again plays the role of interpreter to communicate with both the user and the computer in languages that they both understand. 5. Types of Operating Systems: An operating system enables user interaction with computer systems by acting as an interface between users or application programs and the computer hardware. Here is an overview of the different types of operating systems.
Real-time Operating System: It is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. Multi-user and Single-user Operating Systems: Computer operating systems of this type allow multiple users to access a computer system simultaneously. Time-sharing systems can be classified as multi-user systems as they enable a multiple user access to a computer through time sharing.
Multi-tasking and Single-tasking Operating Systems: When a single program is allowed to run at a time, the system is grouped under the single-tasking system category, while in case the operating system allows for execution of multiple tasks at a time, it is classified as a multi-tasking operating system. Batch Processing and Interactive Systems: Batch processing refers to execution of computer programs in ‘batches’ without manual intervention. In batch processing systems, programs are collected, grouped and processed on a later date.
Online and Offline Processing: In online processing of data, the user remains in contact with the computer and processes are executed under control of the computer’s central processing unit. Also, there are several types of operating system, defined according to whether they can simultaneously manage information measuring 16 bits, 32 bits, 64 bits or more. System| Programming| Single user| Multi-user| Single task| Multi-task| DOS| 16 bits| X| | X| | Windows3. 1| 16/32 bits| X| | | not pre-emptive| Windows95/98/Me| 32 bits| X| | | cooperative| WindowsNT/2000| 32 bits| | X| | pre-emptive|
WindowsXP| 32/64 bits| | X| | pre-emptive| Unix / Linux| 32/64 bits| | X| | pre-emptive| MAC/OS X| 32 bits| | X| | pre-emptive| VMS| 32 bits| | X| | pre-emptive| 6. Conclusion: Operating systems are considered as an essential part of a working computer system. It manages your computer’s tasks and optimizes your computer’s performance. Operating systems also interact with your input and output devices connected to a computer. Operating systems also interact with your computer programs and applications. Without an operating system, a computer or a controlled device cannot be used to its full potential.
