To improve the performance and to avoid the CPU idle time the operating system uses two approaches which are explained below in detail.BufferingIt is a method of overlapping input, output and processing of a single job.After reading the data, the CPU is about to start operating on it, the input ... Read More

There are different operating systems for different kinds of computers and processors. They are divided into different categories.Single processor systemSingle CPU or processor that manages the computer and it runs on a different operating system, and performs a number of tasks using one processor called a single processor system.In a ... Read More

The design of the operating system should be defined by the goals and specifications which are affected by hardware and systems. Thus there would be user goals and system goals for an OS.User GoalsThe user goals or requirements should be as follows −The OS usage should be convenientShould be easy ... Read More

System call provides an interface between user program and operating system. It is represented as follows −When the user wants to give an instruction to the OS then it will do it through system calls. Or a user program can access the kernel which is a part of the OS ... Read More

The different system calls are as follows −System calls for Process managementSystem calls for File managementSystem calls for Directory managementLet us understand them one by one.System calls for Process managementA system is used to create a new process or a duplicate process called a fork. The duplicate process consists of ... Read More

System call mechanism is one of the techniques by which a user program requests for services from the kernel. System calls always provide an interface to the services that are available by an operating system.Let us see the step by step explanation of system call mechanism as given below −Step ... Read More

Locality of reference refers to the tendency of the computer program to access the same set of memory locations for a particular time period. The property of Locality of Reference is mainly shown by loops and subroutine calls in a program.On an abstract level there are two types of localities ... Read More

Instruction cycle consists of fetch, execute and interrupt stage show in below diagram −If any interrupt occurs, it is indicated by an interrupt flag. The CPU will go to interrupt handler routine. Interrupt handler then checks the type of interrupt and executes the appropriate function. It involves overhead but still ... Read More

An interrupt is a signal from a device attached to a computer or from a program within the computer that requires the operating system to stop and figure out what to do next.Whenever an interrupt occurs, it causes the CPU to stop executing the current program. Then comes the control ... Read More

Memory is a storage part in a computer system. It is used to store the data, information, and programs at the time of processing on the computer. It stores data either temporarily or permanent. The main use of memory is saving and retrieving data.Types of MemoryGenerally computer system consists of ... Read More