Use of Interrupts in OS

The OS is responsible for coordinating all the activities within a computer. It makes extensive use of interrupts to perform I/O operations and communicate with and control the execution of all programs. The interrupt mechanism enabled the operating system to assign priorities, switch from one user program to another, implement security and protection features, and co-ordinate securiy features and activities. We will discuss some of these features briefly. A discussion of OS is outside the scope of this book.

The OS incorporates the interrupt service routines for all devices connected to the computer. Application programs do not perform I/o operations themselves. When an application program needs an input or an output operation, it points to the execution of that program temporarily and performs the requested I/O operation. The OS suspends the execution of that program temporarily and performs the required I/O operations.