[MSDN Library April 2000] 3.5.1 Getting a System-assigned Interrupt Vector, DIRQL, and Processor Mask (31.1372872176352%)
MSDN Library - April 2000 > DDK Documentation > Windows NT 4.0 DDK > Kernel-Mode Drivers > Design Guide > Chapter 3 NT Objects and Support for Drivers > 3.5 Interrupt Objects