Int 21 Fn 4400  - Dos 2+ - Ioctl - Get Device Information                  [D]

   AX = 4400h
   BX = handle

Return: CF clear if successful
       DX = device information word (see #1110)
       AX destroyed
   CF set on error
       AX = error code (01h,05h,06h) (see #1366 at AH=59h/BX=0000h)

Notes: value in DH corresponds to high byte of device driver's attribute word
     if handle refers to a character device
   Novell NetWare reportedly does not return a drive number in bits 5-0
     for a disk file
   this function was not supported by Digital Research's DOS-Plus

See Also: AX=4401h,INT 2F/AX=122Bh

Bitfields for device information word:
Bit(s) Description (Table 1110)
 character device
  14   device driver can process IOCTL requests (see AX=4402h"DOS 2+")
  13   output until busy supported
  11   driver supports OPEN/CLOSE calls
   8   ??? (set by MS-DOS 6.2x KEYB)
   7   set (indicates device)
   6   EOF on input
   5   raw (binary) mode
   4   device is special (uses INT 29)
   3   clock device
   2   NUL device
   1   standard output
   0   standard input
 disk file
  15   file is remote (DOS 3.0+)
  14   don't set file date/time on closing (DOS 3.0+)
  11   media not removable
   8   (DOS 4 only) generate INT 24 if no disk space on write or read past
     end of file
   7   clear (indicates file)
   6   file has not been written
  5-0  drive number (0 = A:)

See Also: INT 29