Int D4 Fn 03  - PC-mos/386 V5.01 - Get/set Extended Directory Information  [O]

   AH = 03h
   AL = subfunction (00h get, 01h set)
   DS:(E)DX -> pathname
   ES:(E)BX -> 10-byte buffer for directory information (see below)

Return: CF clear if successful
       AL = permitted access level for file (00h-03h)
       ES:(E)BX -> modified buffer (AL=01h on entry)
   CF set on error
       AX = error code (see INT 21/AH=59h)

Notes: BX/DX are used in V86 mode, EBX/EDX in native mode
   the file class cannot be changed for files because it affects the
     encryption method, but directories can have their classes changed

Format of directory information:
Offset Size    Description
 00h   BYTE    reserved (0)
 01h   BYTE    file class ('A'-'Z' or 00h)
 02h   DWORD   user ID of file creator
 06h   WORD    file creation time (see INT 21/AX=5700h)
 08h   WORD    file creation date (see INT 21/AX=5700h)