INT 2F U - DOS 3+ 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

See also: 2F1219

2F1217 - DOS 3+ internal - GET CURRENT DIRECTORY STRUCTURE FOR DRIVE