Stupid DOS tricks-redirecting console

From: Hans Franke <>
Date: Fri Aug 4 12:05:52 2000

> It's been a long time since I've banged around pure DOS, so I can't
> remember all of its tricks. Here's what I want to do. I want to occasionally
> hook a terminal to a small 486 SBC/data collector which is running
> "headless." I seem to remember that the console I/O can be redirected to a
> COM port with a command like "MODE COM1:=CON" or something like that. I'm
> not at home now, so I can't try it, but am I on the right track? Will that
> redirect both screen and keyboard I/O?

CTTY <dev>


CTTY CON will reset to startup conditions.

The command is available starting with DOS 2.0 and
schould still work fine with DO above 5.0 (never tested)

You may assign any two way character device (Well,
depending on your drivers one way devices may also
produce _some_ result.

Be aware that _only_ the DOS in/output functions are
redirected. Only programms using INT 21h 01h-0Ch
(except the AUX and Print functions 04h-06h) will
produce acceptable results. all other ways, including
BIOS character I/O may or may not work, depending
on your version of DOS (Basicly the BIOS functions
will not work, but there are some special Versions
of DOS (or DOSalikes) where CTTY is also redirecting
the BIOS functions).

may be used to redirekt printer output to your terminal
(DOS 3.2 and above).


VCF Europa 2.0 am 28./29. April 2001 in Muenchen
Received on Fri Aug 04 2000 - 12:05:52 BST

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