Operating System

  Real time Operating System : Real time   Operating Systems  are very fast and quick respondent systems. These systems are used in an environment where a large number of events must be accepted and processed in a short period of time. Real time processing requires quick transaction and characterized by supplying immediate response.             In real time operating system there is a little swapping of programs between primary memory and secondary memory. Most of the time, processes remain in primary memory in order to provide quick response, therefore, memory management in real time system is less demanding compared to other operating system.   Functions: 1)       Manage the processor and other system resources to meet the requirements of an application. 2)       Synchronize with and respond to the system events. 3)   ...

  Distributed Operating System : A Distributed   Operating System  is a representation where distributed applications are running on multiple computers linked by using communications. A distributed operating system is an extension of the network operating system that supports higher levels of communication and integration of the machines on the network. They handle jobs which are serviced by multiple CPU. Each individual computer holds a specific software subset of the global build-up operating system. Each subset is a combined of two different service providing.   The first is all-over micro-kernel, which directly controls that computer hardware. Second is a higher-level collection of system management components that coordinate the computer individual and pull together activities. These components abstract micro-kernel functions and support user applications. The micro-kernel and the management components collection work together. They support the syste...

Time Sharing Operating System : A  time sharing system  allows many users to share the computer resources simultaneously. In other words, time sharing refers to the allocation of computer resources in time slots to several programs simultaneously. For example- a mainframe computer that has many users logged on to it. Each user uses the resources of the mainframe that is memory, Microprocessor etc. The time sharing systems are developed to provide an interactive use of the computer system. A time shared system uses CPU scheduling and multi-programming to provide each user with a small portion of a time shared computer. It allows many users to share the computer resources simultaneously. As the system switches rapidly from one user to the other user, a short time slot is given to each user for their executions program.The time sharing system provides the direct access to a large number of users where CPU time is divided among all the users on scheduled basis. The oper...

  Multi-programming : Multi-programming means the two or more job or task at a same time in computer memory. The job is loaded into the system and processed one at time. That is, once loaded a job will remain in the main memory until its execution is completed and the next job will be loaded only after the completion of the previous job.                As shown in above diagram above area of main memory occupy by operating system, and remaining area is available for user program. In the above diagram job1 is writing data to the secondary memory and on jab 2 allocated CPU time.   Multi-programming is the name given to the interleaved execution of two or more different and independent programs by the same computer. We have been introduced to the idea of having two programs in the main memory at the same time. The operating system for overall system control and the user program for performing in the main memory and executing them con...