INT 0A - IRQ2 - LPT2 (PC), VERTICAL RETRACE INTERRUPT (EGA,VGA)
Notes:  the TOPS and PCnet adapters use this interrupt request line by default
        DOS 3.2 revectors IRQ2 to a stack-switching routine
        on ATs and above, the physical data line for IRQ2 is labeled IRQ9 and
          connects to the slave 8259.  The BIOS redirects the interrupt for
          IRQ9 back here.
        under DESQview, only the INT 15h vector and BASIC segment address (the
          word at 0000h:0510h) may be assumed to be valid for the handler's
          process
        many VGA boards do not implement the vertical retrace interrupt,
          including the IBM VGA Adapter where the traces are either cut or
          removed
SeeAlso: INT 5A"DoubleDOS",INT 71,INT 7A"GO32"