- An interrupt (INT) is an interruption sequence that interrupts a running program in favor of another, more urgent program. When an interrupt occurs, which is usually requested by an interrupt request( IRQ), a check routine checks the importance of the interruption and decides whether to grant it. Before the transition to the other program, the processor saves all data necessary for the continuation of the running program into a special memory area, the "stack". Then the processor processes the new routine and resumes the running program after processing the interrupt routine. There are hardware and software interrupts. The former are intended for hardware components, the latter for certain computer functions such as the Basic Input/Output System( BIOS).
- Reverse interrupts are spoken of in bisynchronous processes when the receiving station sends a control character sequence to query in advance the completion of further transmission.