INT 15 - Phoenix BIOS 4.0 Rel 6.0 - ???

	AX = 5380h
	BX = 8000h
	CX = 0020h
Return: ???
Note:	although a check for the indicated value is present in the examined
	  copy of the BIOS, no code was associated with it (possibly an OEM
	  option not included in that copy) and this function always returns
	  CF set/AH=03h if CX=0020h and CF set/AH=86h for CX<>0020h
SeeAlso: AX=5380h/BX=8001h