Int 2F Fn 12FF  - Freedos - Fdak-ddt - Installation Check / Status Check   [O]

   AX = 12FFh
   BL = 00h

Return: AL = DDh if installed
       BH = state (00h disabled, nonzero enabled)
       BL = readonly flag (00h writable, nonzero read-only)
Program: FDAK-DDT is the FreeDOS Alternative Kernel Device Drivers Testing
     release by Yury A. Semenov

See Also: AX=12FFh/BL=07h