This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
(A copy of the GNU General Public License can be found in the file
COPYING
in the top-level directory.)
http://www.cam.org/~nico/brltty
.BRLTTY represents the work of a team, which includes
Comments, suggestions, criticisms and contributions are welcome. We will try to respond promptly to all (sensible) mail, but give no guarantee. In general, we suggest you send email messages to both active developers.
If you have a query about a particular display type supported by
BRLTTY, you may want to contact the author of that particular driver.
See the README
file in the relevant subdirectory for contact
details.
From version 1.0.1, BRLTTY can run as a stand-alone executable,
without any configuration files. In this case the compiled-in
defaults will be used. If the directory /etc/brltty
(used to
store the configuration file, the online help file and the table
files) is not present, BRLTTY looks in /etc
for the help file
brlttydev.hlp
and the configuration file brlttyconf.dat
.
Even if these are not present, BRLTTY will still work!
If, for some reason, you ever create the /etc/brltty
directory by hand,
it is important to set the permissions so that only root can create files
in that directory.
Note: The /dev/vcsa0
device is also required. It should already be
present unless your Linux distribution is quite old. You can create it with:
mknod /dev/vcsa0 c 7 128
chown root.tty /dev/vcsa0
chmod 660 /dev/vcsa0
When constructing floppy rootdisks for installation or rescue purposes, space is often of the essence. This new resiliance allows BRLTTY to be installed as a single executable on such disks, reducing the space requirement.
Note: The script install-brltty
assumes a complete installation
of BRLTTY is to be copied.
One problem often encountered when trying to use BRLTTY in an uncertain
environment like a bootdisk or an incomplete system is that BRLTTY might not
find the shared libraries it requires. Bootdisks often use smaller but outdated
versions of the libraries which may not work. The solution is to compile
BRLTTY with the -static
flag (see Makefile). This removes any dependency
on shared libraries, but unfortunately produces a larger executable.
The executable is stripped during the make install
. If you take the
executable straight from the compilation directory, don't forget to
strip
it.
Apart from fixing bugs and supporting more types of Braille display, we hope, time permitting, to work on some or all of the following:
Attribute tracking, mixed text and attribute mode etc.
Linear (as opposed to rectangular) cut mode.
A greater variety of beeps.
Locking the Braille window on one line as it scrolls on the screen.
Mixed Braille and speech for faster reading of text.
This would also allow faster reading of text.
See the TODO file for a more complete list.
This software has been tested on
At the time of writing (March 1999), the following problems are known:
Routing is implemented by a looping sub-process which runs at lowered priority to avoid using too much cpu time. Different system loads require different settings of the parameters here. The defaults work excellently in a standard Unix editor on a fairly lightly loaded system, but very badly in other situations, e.g. over a slow serial link to a remote host.
Keystroke simulation of any kind does not work correctly in DOSEmu's raw keyboard mode. This is because keystroke simulation must be done differently in this case, possibly by using scan codes. This affects the cursor routing and cut & paste functions.
There is a bug in the Linux kernel 2.0.35 which causes console beeps to never stop once started. We have found a way to avoid this problem in the current version of BRLTTY.