INT 21,1F - Get Pointer to Current Drive Parameter Table
(Undocumented) AH = 1F DL = drive number (0=default, 1=A, ...) on return: AL = 00 DS:BX is pointer to drive parameter table (DPT) FF drive does not exist DS:BX = pointer to drive parameter table (DPT) if AL=0 - the format of the DPT varies between DOS versions - calls INT 21,32 with DL=00 for DOS version 2.x+