INT 2F - Multiplex - ??? - INSTALLATION CHECK???
AX = E700h
BX = 4158h ("AX")
CX = 4953h ("IS")
DX = 4845h ("HE")
Return: AL = FFh if installed
BX = 4C4Fh ("LO") if ??? installed
CX = 4F4Bh ("OK")
DX = 4F55h ("OU")
ES:DI -> ???
Range: AH=C0h to AH=FFh, selected by scanning AH=E7-FFh, then AH=C0h-E6h
Note: called by QDPMI when its Real to Protected Mode Switch Entry Point
is called