INT 2F - DOS 3.0+ internal - GET CURRENT DIRECTORY STRUCTURE FOR DRIVE

	AX = 1217h
	SS = DOS DS (must be using a DOS internal stack)
	STACK: WORD drive (0 = A:, 1 = B:, etc)
Return: CF set on error
	    (drive > LASTDRIVE)
	CF clear if successful
	    DS:SI -> current directory structure for specified drive
	STACK unchanged
SeeAlso: AX=1219h