Int 21 Fn 71A0  - Windows95 - Long Filename - Get Volume Information       [D]

   AX = 71A0h
   DS:DX -> ASCIZ root name (e.g. "C:\")
   ES:DI -> buffer for file system name
   CX = size of ES:DI buffer

Return: CF clear if successful
       AX destroyed (0000h and 0200h seen)
       BX = file system flags (see #1472)
       CX = maximum length of file name [usually 255]
       DX = maximum length of path [usually 260]
       ES:DI buffer filled (ASCIZ, e.g. "FAT","NTFS","CDFS")
   CF set on error
       AX = error code
       7100h if function not supported

Notes: for the file system name buffer, 32 bytes should be sufficient; that's
    what is used in some sample code by Walter Oney from Microsoft.
   this function accesses the disk the first time it is called
BUG:   this function returns DX=0000h for CD-ROM drives under Win95 SP1

See Also: AX=714Eh,AX=7160h/CL=00h

Bitfields for long filename volume information flags:
Bit(s) Description (Table 1472)
 0 searches are case sensitive
 1 preserves case in directory entries
 2 uses Unicode characters in file and directory names
 3-13  reserved (0)
 14    supports DOS long filename functions
 15    volume is compressed