Int 2F Fn DD  - Xdisk V3.32+ - Installation Check                          [d]

   AH = DDh
   BX = 7844h ('xD')
   CX = 4953h ('IS')
   DX = 4B3Fh ('K?')
   AL = desired drive (01h-1Ah) or 00h to check for xDISK on any drive
   ES:DI -> 25-byte data buffer (see #2771)

Return: AX = DDFFh if installed (on specified drive if AL nonzero on entry)
      BX = 87BBh
      DX = B4C0h
      ES:DI buffer filled
   CX,CF destroyed

See Also: INT 21/AX=4404h"xDISK",INT 21/AX=4405h"xDISK"

Format of xDISK data buffer:
Offset Size    Description (Table 2771)
 00h   DWORD   pointer to ASCIZ driver signature "xDISK unit: X"
 04h   BYTE    flag: 01h if disk linked to DOS, 00h if unlinked
 05h   BYTE    flag: 01h if write protected, 00h if not
 06h   BYTE    flag: 01h if root directory full, 00h if not
 07h   BYTE    flag: 01h if free space uncompacted, 00h if compacted
 08h   BYTE    resizing state: 00h not resizable, 01h resized, 80h resizable
 09h   BYTE    flag: 01h inelastic resizable disk, 00h elastic
 0Ah  2 BYTEs  reserved
 0Ch   BYTE    flag: 01h collapsed disk, 00h not collapsed
 0Dh   BYTE    flag: 01h using all EMS, 00h some EMS free
 0Eh   BYTE    flag: 01h password enabled, 00h disabled
 0Fh   BYTE    flag: 01h password audio feedback, 00h no feedback
 10h   BYTE    flag: 01h password video feedback, 00h no feedback
 11h   BYTE    flag: 01h confirm changes, 00h no confirmation
 12h   BYTE    flag: 01h terse display, 00h verbose display
 13h   BYTE    flag: 01h click speaker on disk access, 00h no click
 14h   BYTE    flag: 01h flash icon on disk access, 00h no icon flash
 15h   BYTE    FAT entry size: 00h 12-bit, FFh 16-bit
 16h   WORD    count of open files in RAM disk
 18h   BYTE    unused