Int 21 Fn 6B  U - Dos 4.0 Internal - Ifs Ioctl                             [D]

   AH = 6Bh
   AL = subfunction
       00h ???
       DS:SI -> Current Directory Structure???
       CL = drive (1=A:)
       01h ???
       DS:SI -> ???
       CL = file handle???
       02h ???
       DS:SI -> Current Directory Structure???
       DI = ???
       CX = drive (1=A:)

Return: CF set on error
       AX = error code (see #1366 at INT 21/AH=59h/BX=0000h)
   CF clear if successful

Notes: passed through to INT 2F/AX=112Fh with AX on top of stack
   Novell DOS 7 Update 15 returns CF set/AX=0001h (invalid function)

See Also: AH=6Bh"DOS 5",INT 2F/AX=112Fh