stdaux

[Holger Brockhausen]

Does anybody know what stdaux is ?? (int 21,3)

Holger Brockhausen
Hol...@via.at

[Ray Moon]

Holger Brockhausen wrote:
>
> Does anybody know what stdaux is ?? (int 21,3)

Holger,

STDAUX is one of the five standard devices that DOS opens automatically
when an application is loaded and executed. The handle is 3, and the
default device is AUX or the serial port. This means that you can
read and write to the serial port without opening it first.

Hope that this helps,

Ray
=====================================================================
Ray Moon
ray...@moonware.dgsys.com
http://www2.dgsys.com/~raymoon/moonware.html
Home of MoonWare Shareware and the x86 Assembly Language FAQ
Come steal my pages... Well, not steal but come and see!

[Jaime A. Stuardo B.]

> Holger Brockhausen <Hol...@via.at> wrote in article
<31C65A...@via.at>...

> Does anybody know what stdaux is ?? (int 21,3)
>

> Holger Brockhausen
> Hol...@via.at
>

STDAUX is the standard auxiliary device, which defaults to COM1. Normally,
COM1 has a default initialization of 2400, 8N1. Functions 3 and 4 of INT
21h reads from and writes to the auxiliary device. The default handler to
that device is 3, so you can use functions 3Fh to read from it and 40h to
write to it, instead. You can use BIOS functions or direct access to
serial ports to initialize it. I have understood that support for these
functions may end at any time.

I hope this explanation clarify you.

Greetings,

-------------------------------------------------------------------------
Jaime A. Stuardo B.
Ingeniería Civil Electrónica
Universidad Técnica Federico Santa María
Valparaíso, CHILE
-------------------------------------------------------------------------

[Jeff Patterson]

On Tue, 18 Jun 1996, Holger Brockhausen wrote:

> Does anybody know what stdaux is ?? (int 21,3)

> Holger Brockhausen
> Hol...@via.at

Could be for using the AUX device (by default I think it is COM1).

According to "The Programmer's PC Sourcebook" it is superceeded by
int 21,3f which is Read File or Device which probably would use the AUX
device name.

for int 21,3 the book also mentioned that DOS initializes the STDAUX
device to 2400 baud 8N1 which should show its probably an RS232 port.

I tried echoing to AUX and it is sending output to my COM1 device (my modem).

[Adrian Cheater]

On Tue, 18 Jun 1996, Holger Brockhausen wrote:

> Does anybody know what stdaux is ?? (int 21,3)

As far as I know. It's the standard auxillury (sp) file handle. I
think it points to COM2: by defualt. Can anyone here comfirm this? At any
rate DOS uses it to communicate to something, and the place it goes is
redirectable. Sorry if this is kinda vague, I don't have my reference
handy, so I'm going off the top of my head.

Adrian Cheater acf...@freenet.mb.ca