please dont rip this site
Function  44h   I/O Control for Devices (IOCTL)  Get or Set Device Information

entry AH 44h

AL 00h Get Device Information (from DX)

BX file or device handle

return DX device info

If bit 7 set: (character device)

bit 0: console input device

1: console output device

2: NUL device

3: CLOCK$ device

4: device is special

5: binary (raw) mode

6: not EOF

12: network device (DOS 3.x)

14: can process IOCTL control

strings (func 2-5)

If bit 7 clear: (file)

bits 0-5: block device number

6: file has not been written

12: Network device (DOS 3.x)

15: file is remote (DOS 3.x)

Function 44h I/O Control for Devices (IOCTL) Get or Set Device Information

entry AH 44h

00h Get Device Information (from DX)

note This function can be used to detect input and output redirection. Since

the handle for STDOUT is always 1, if after calling Int 21 with AX=4400h

and BX=0001h, the character device bit (bit 7) and the console output

device bit (bit 1) are set in DX, anything sent to STDOUT will appear on

the screen. If bit 7 is clear, we know output is being redirected to a

file. If bit 1 is zero, the redirection is to another device.

file: /Techref/INT/21f/44sf/00.htm, 1KB, , updated: 1999/4/26 12:36, local time: 2024/7/14 23:14,

 ©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!

<A HREF=""> INT 21f 44sf 00</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type a nice message (short messages are blocked as spam) in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?


Welcome to!


Welcome to!