Operating System:

Operating System:

System view: From the computer's point of view the operating system is the program most intimately involved with the hardware . In this context we can view an operating system as a Resource allocator.

A computer system has many resources that may be required to solve a problem. Example: the cpu time, memory space, file storage space, input output devices and so on. The operating system acts as the manager of these resources facing numerous and possibly conflicting requests for resources. The operating system must decide how to allocate these to specific programs and user , so that it can operate the computer system efficiently and fairly.

A slightly different view of an operating system emphasize the need to control the various input output devices and user programs.

An operating system is a control program. A control program manages the execution of user' s programs. It is specially concerned with the operation and control of input output devices.

Computer System Architecture:

• Single processor systems: On a single processor system there is one main cpu is capable executing a general purpose instructions set, involving instructions from the user's processes. All of these processors runs a limited instructions set and sometimes they are managed by the operating system. In that the operating system sends them information about their next task and monitors their status.