Int 21 Fn 5F00  - Dos 3.1+ Network - Get Redirection Mode                  [D]

   AX = 5F00h
   BL = redirection type
       03h printer
       04h disk drive

Return: CF set on error
       AX = error code (see #1366 at AH=59h/BX=0000h)
   CF clear if successful
       BH = redirection state
       00h off
       01h on

Note:  calls INT 2F/AX=111Eh with AX on top of the stack

See Also: AX=5F01h,INT 2F/AX=111Eh