INT 0bH is a hardware-generated interrupt (IRQ 3) forced by COM2 or COM4 when it is done sending or receiving a byte of data. █▌CPU Exception Interrupt▐█ 286+ computer execute INT 0bH when the CPU is in protected mode and it detects a Segment Not Present exception. See Also: IRQs: Hardware Interrupts Serial Ports BIOS Data Area ROM-BIOS Functions DOS Functions -♦-