Int 7F Fn 06  - Alloy Ntnx (host) - Get Shared Drive Info                  [N]

   AH = 06h
   AL = drive number (1=A:, 2=B:, etc)
   ES:DI -> drive info record (see below)

Return: AX = status
       0000h successful
       ES:DI buffer filled
       0001h not shared drive

Format of drive info record:
Offset Size    Description
 00h   WORD    segment of drive IO-REQUEST structure (MS-DOS DPB)
 02h   WORD    segment of allocation map (owner table)
       one byte per FAT entry, containing user ID owning that entry
 04h   WORD    segment of master FAT for drive (copy of FAT on disk)
 06h   WORD    pointer to configuration file
 08h   WORD    total number of clusters
 0Ah   WORD    bytes per sector
 0Ch   WORD    sectors per cluster
 0Eh   BYTE    FAT type (0Ch = 12-bit, 10h = 16-bit)