INT 4F - ATA Software Programming Interface (ATASPI) - INSTALLATION CHECK
	AX = 0082h
	CX = 8765h
	DX = CBA9h
Return: AH = 00h if installed
	    CX = 9ABCh
	    DX = 5678h
	    ES:DI -> "$ATAMGR$"
Note:	this interface has probably appeared in some later revisions of ATASPI
	  than 0.72
SeeAlso: INT 21/AX=4402h"ATASPI",INT 4F/AX=0081h