Int 21 Fn 440E  - Dos 3.2+ - Ioctl - Get Logical Drive Map                 [D]

   AX = 440Eh
   BL = drive number (00h=default,01h=A:,etc)

Return: CF set on error
       AX = error code (01h,0Fh) (see #1366 at AH=59h/BX=0000h)
   CF clear if successful
       AL = 00h block device has only one logical drive assigned
        1..26 the last letter used to reference the drive (1=A:,etc)

Notes: DR DOS 3.41-5.0 DRIVER.SYS does not support drive mapping and thus
     always returns AL=00h
   in addition to the normal operation, if Stacker is installed, this
     call also sets the volume number at offset 58h in the Stacker
     device driver (DR DOS 3.41-5.0 only; use AX=4408h otherwise)
     (see AX=4404h"Stacker",INT 25/AX=CDCDh)

See Also: AX=4408h,AX=440Fh,INT 2F/AX=122Bh