INT 21,44,0 / IOCTL,0 - Get Device Information

AH = 44h

AL = 00

BX = handle (must be an opened device)

on return

AX = error code if CF set (see ~DOS ERROR CODES~)

DX = device information (see tables below)

�F�E�D�C�B�A-8�7�6�5-0� DX Block Device Information

� � � � � � � � +----- drive number (0=A:,1=B:)

� � � � � � � +------- 0 = file has been written

� � � � � � +-------- 0 = disk file; 1 = character device

� � � � � +---------- reserved, must be zero

� � � � +------------ 1 = media not removable

� � � +------------- 1 = network device (DOS 3.x+)

� � +-------------- 1 = reserved

� +--------------- 1 = don't update file time or date (DOS 4.x+)

+---------------- 1 = file is remote (DOS 3.x+)

�F�E�D�C�B�A-8�7�6�5�4�3�2�1�0� DX Character Device Information

� � � � � � � � � � � � � +---- 1 = standard input device

� � � � � � � � � � � � +---- 1 = standard output device

� � � � � � � � � � � +---- 1 = NUL device

� � � � � � � � � � +---- 1 = clock device

� � � � � � � � � +---- uses DOS ~INT 29~ for fast character output

� � � � � � � � +---- 1 = binary mode, 0 = translated

� � � � � � � +---- 0 = end of file on input

� � � � � � +---- 1 = character device, 0 if disk file

� � � � � +----- reserved

� � � � +------ 1 = media not removable

� � � +------ 1 = network device (DOS 3.x+)

� � +------ reserved

� +------ 1 = supports IOCTL, via functions 2 & 3

+------ reserved

- BIT 7 of register DX can be used to detect if STDIN/STDOUT is

redirected to/from disk; if a call to this function has DX BIT 7

set it's not redirected from/to disk; if it's clear then it is

redirected to/from disk

- BIT B of register DX can be used to determine if a drive is

removable.