To understand system calls, first one needs to understand the difference between kernel mode and user mode of a CPU. Every modern operating system supports these two modes. In computing, a system call is the programmatic way in which a computer program requests a service from the kernel of the operating system it is executed on. A system… Read More »
Dual-mode operation forms the basis for I/O protection, memory protection and CPU protection. Two modes are provided by the hardware – user and kernel mode. Mode bit is added to computer hardware to indicate the current mode. When system boots, hardware starts in kernel mode. The OS is loaded and then user process is started in user mode.… Read More »
The Operating system (OS) acts as a host for application programs that are run on the machine. Operating system (OS) is a software which acts as an interface between the end user and computer hardware. Every computer must have at least one OS to run other programs. In simple terms, an operating system is the interface between the… Read More »
An Operating System (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. Application programs usually require an operating system to function. The fundamental goal of a Computer System is to execute user programs and to make tasks easier. There are various types of operating systems. Applications of Operating System… Read More »
A process is a program in execution. Process States in Operating System : Each process goes through different states in its life cycle- New (Create) : Newly Created Process (or) being-created process. Ready : A process moves from new state to ready state after it is loaded into the main memory and is ready for execution. The process… Read More »
Operating systems were first developed in the late 1950s to manage tape storage. The present-day popular OS Windows first came to existence in 1985 when a GUI was created and paired with MS-DOS. An Operating System acts as a communication bridge (interface) between the user and computer hardware. The purpose of an operating system is to provide a… Read More »