Int 81 Fn 2012  - Gravis Ultrasound - Mega_em V3.0+ - Soundcard Irq Redir  [s]

   AX = 2012h
   ???

Return: ???

Note:  MegaEm calls this function from its GUS IRQ handler, and then
     immediately returns; this permits it to operate while hooking only
     one interrupt through the memory manager in protected mode

See Also: AX=2010h,AX=2011h