Int 31 Fn EE21  - Dos32 V3.0+ - Get Real Mode Call Back Address With Iret  [E]

   AX = EE21h
   ESI = offset of the real mode call back function

Return: CF clear if successful
       CX:DX = real mode address to call up to the protected mode
         procedure
   CF set on error

See Also: AX=EE20h