What is an operating system.docx Essays - Computer Architecture

394335462987 Jarrod Davis October 8, 2017 Computer apps in business DR. NEGA LAKEW Operating SYstems 00 Jarrod Davis October 8, 2017 Computer apps in business DR. NEGA LAKEW Operating SYstems What is an operating system? An operating system (OS) is a set of programs that coordinates all the activities among computers or mobile devices hardware. It is the software that supports a computer or mobile devices basic functions, such as scheduling tasks, executing applications, and controlling peripherals. All programs within a computer or mobile device require an operating system in order to be able to function. Operating systems are generally already in place on the device, but can be updated and sometimes even modified to the users liking. An OS needs to be efficient. It should respond the user in a proactive way. Also, it uses the system resources without wastage and efficiently. An OS should be flexible enough to incorporate new functions in the system without any interference with the services.There are two main reasons why operating systems have been developed. First is that it allocates and uses computer resources in different tasks. Secondly, it acts as an interface between computer hardware and programmer. OS allows the application programs to be created and debugged. There are five main services that are provided by an OS. The first service that OS provides is program execution. OS is responsible for providing a safe environment to run user programs. On the back end, OS handles memory management and scheduling of the program. The user doesn't need to worry about these things. When the user asks for a program to run, OS allocates a memory and schedules the process accordingly. Once the program is finished, the memory is de-allocated. The second service that an OS takes care of is handling input and output operations. Every program running in the system has an input and produces an output. The OS hides the information of hardware underneath. When an interrupt occurs by an input/output devices, OS runs the interrupt handler routine. The user level programs are not made to handle input/output. The third service provided by an OS is manipulation of the file system. The read/write feature done in file is handled by the OS which are created by OS in the file system using system calls. The user does not need to worry about how the file will be created and becomes visible to him once created by the OS. Secondary storage management is also done by the operating system itself. It is very critical to handling input/output efficiently, which mainly depends on the storage management. This also affects the speed of various programs. It is not preferable to leave the management of secondary storage to user programs and should be handled by the OS itself. The fourth service that OS provides is communication. The processes need to communicate with each other in order to share the information. The communication can take place between two programs running on the same machine or different ones. This way the user can easily pass messages to other computers through the network. The user program is written keeping in mind the hardware through which message is sent. The fifth, and one of the most important services is error detection. One main concern in any system is an error detection. In order to avoid errors occurring, the operating system keeps track of the errors or exception occurring in the system. This helps the user not to worry about any errors emerging and causing any harm to the system. A user program is not capable to handle this service because it is not given any rights to allocate or de-allocate memory without OS permissions. For example, if a CPU gets stuck in an infinite loop, the user program might not be able to handle it as this permission is not given to it. What does an operating system contain? An operating system contains many parts including an assembler, compiler, loader, and an input and output manager. An assembler is a program that translates an assembly language program to machine language. An assembly language is particular for each operating system and varies accordingly. A compiler or an interpreter is responsible for processing high level machine languages like C++, Java,