interrupt LastModified: Tuesday, January 27, 2004
(n.) A signal informing a program that an event has occurred. When a program receives an interrupt signal, it takes a specified action (which can be to ignore the signal). Interrupt signals can cause a program to suspend itself temporarily to service the interrupt. Interrupt signals can come from a variety of sources. For example, every keystroke generates an interrupt signal. Interrupts can also be generated by other devices, such as a printer, to indicate that some event has occurred. These are called hardware interrupts. Interrupt signals initiated by programs are called software interrupts. A software interrupt is also called a trap or an exception. PCs support 256 types of software interrupts and 15 hardware interrupts. Each type of software interrupt is associated with an interrupt handler -- a routine that takes control when the interrupt occurs. For example, when you press a key on your keyboard, this triggers a specific interrupt handler. The complete list of interrupts and associated interrupt handlers is stored in a table called the interrupt vector table, which resides in the first 1 K of addressable memory. Also see the list of IRQ numbers in the Quick Reference section of Webopedia. (v.) To send an interrupt signal.
Interrupt Function and Operation  Detailed description of hardware interrupts from "The PC Guide". Contains separate sections on interrupt controllers, IRQ lines, interrupt priority, interrupt conflicts, and Non-Maskable Interrupts (NMI). Interrupt list Contains a listing of interrupt calls, I/O ports, memory locations, and far-call interfaces for IBM PCs and compatible machines.	related categories: Operating Systems related terms: event event handler exception fatal exception error interrupt vector table IRQ Shopping interrupt Products Compare Products,Prices and Stores Shop by Category: Tools and Accessories 144 Store Offers Security Systems and Surveillance 32 Store Offers Office Supplies 8 Store Offers Books 49 Model Matches