INTERRUPT Services: On the systems running on DOS based platform, certain i/o services are provided by hardware and the operating system. These services are called ROM-BIOS services and DOS services and are the form of interrupts. Need for Interrupt: Interrupts are particularly useful when interfacing I/O devices, that provide or require data at relatively low data transfer rate. Types of Interrupts: There are two types of Interrupts in 8086. They are: (i)Hardware Interrupts  and (ii)Software Interrupts (i) Hardware Interrupts (External Interrupts). 8086 microprocessors support hardware interrupts through: Two pins (17 and 18) that Allow interrupt requests, NMI and INTR One pin that acknowledges, INTA, the interrupt requested on INTR. INTR and NMI INTR;is a maskable hardware interrupt. The interrupt can be enabled/Diabled using STI/CLI instructions or using more complicated method