Int 2F Fn 1220  U - DOS 3+ Internal - Get Job File Table Entry             [D]

   AX = 1220h
   BX = file handle

Return: CF set on error
       AL = 6 (invalid file handle)
   CF clear if successful
       ES:DI -> JFT entry for file handle in current process

Notes: the byte pointed at by ES:DI contains the number of the SFT for the
     file handle, or FFh if the handle is not open
   supported by DR-DOS 5.0+

See Also: AX=1216h,AX=1229h