|
|
Linux Access HOWTO | HowTo Linux | Linux Zone Home | E-Mail Me | Michael De La Rue, <access-howto@ed.ac.uk>
v2.11, 28 March 1997
The Linux Access HOWTO covers the use of adaptive technology with
Linux, In particular, using adaptive technology to make Linux accessi&SHY;
ble to those who could not use it otherwise. It also covers areas
where Linux can be used within more general adaptive technology solu&SHY;
tions.
1. Introduction
The aim of this document is to serve as an introduction to the
technologies which are available to make Linux usable by people who,
through some disability would otherwise have problems with it. In
other words the target groups of the technologies are, the blind, the
partially sighted, deaf and the physically disabled. As any other
technologies or pieces of information are discovered they will be
added.
The information here not just for these people (although that is
probably the main aim) but also to allow developers of Linux to become
aware of the difficulties involved here. Possibly the biggest problem
is that, right now, very few of the developers of Linux are aware of
the issues and various simple ways to make life simpler for
implementors of these systems. This has, however, changed noticeably
since the introduction of this document, and at least to a small
extent because of this document, but also to a large extent due to the
work of some dedicated developers, many of whom are mentioned in the
document's Acknowledgements.
Please send any comments or extra information or offers of assistance
to <access-howto@ed.ac.uk> This address might become a mailing list in
future, or be automatically handed over to a future maintainer of the
HOWTO, so please don't use it for personal email.
I don't have time to follow developments in all areas. I probably
won't even read a mail until I have time to update this document.
It's still gratefully received. If a mail is sent to the blind-list
or the access-list, I will eventually read it and put any useful
information into the document. Otherwise, please send a copy of
anything interesting to the above email address.
Normal mail can be sent to
Linux Access HOWTO
23 Kingsborough Gardens
Glasgow G12 9NH
Scotland
U.K.
And will gradually make its way round the world to me. Email will be
faster by weeks.
I can be personally contacted using <miked@ed.ac.uk>. Since I use
mail filtering on all mail I receive, please use the other address
except for personal email. This is most likely to lead to an
appropriate response.
1.1. Distribution Policy
The ACCESS-HOWTO is copyrighted (c) 1996 Michael De La Rue
The ACCESS-HOWTO may be distributed, at your choice, under either the
terms of the GNU Public License version 2 or later or the standard
Linux Documentation project terms. These licenses should be available
from where you got this document. Please note that since the LDP
terms don't allow modification (other than translation), modified ver&SHY;
sions can be assumed to be distributed under the GPL.
2. Comparing Linux with other Operating Systems
2.1. General Comparison
The best place to find out about this is in such documents as the
`Linux Info Sheet', `Linux Meta FAQ' and `Linux FAQ' (see ``Linux
Documentation''). Major reasons for a visually impaired person to use
Linux would include it's inbuilt networking which gives full access to
the Internet. More generally, users are attracted by the full
development environment included. Also, unlike most other modern GUI
environments, the graphical front end to Linux (X Windows) is clearly
separated from the underlying environment and there is a complete set
of modern programs such as World Wide Web browsers and fax software
which work directly in the non graphical environment. This opens up
the way to provide alternative access paths to the systems
functionality; Emacspeak is a good example.
For other users, the comparison is probably less favourable and less
clear. People with very specific and complex needs will find that the
full development system included allows properly customised solutions.
However, much of the software which exists on other systems is only
just beginning to become available. More development is being done
however in almost all directions.
2.2. Availability of Adaptive Technology
There is almost nothing commercial available specifically for Linux.
There is a noticeable amount of free software which would be helpful
in adaptation, for example, a free speech synthesiser and some free
voice control software. There are also a number of free packages
which provide good support for certain Braille terminals, for example.
2.3. Inherent Usability
Linux has the vast advantage over Windows that most of it's software
is command line oriented. This is now changing and almost everything
is now available with a graphical front end. However, because it is
in origin a programmers operating system, line oriented programs are
still being written covering almost all new areas of interest. For
the physically disabled, this means that it is easy to build custom
programs to suit their needs. For the visually impaired, this should
make use with a speech synthesiser or Braille terminal easy and useful
for the foreseeable future.
Linux's multiple virtual consoles system make it practical to use as a
multi-tasking operating system by a visually impaired person working
directly through Braille.
The windowing system used by Linux (X11) comes with many programming
tools, and should be adaptable. However, in practice, the adaptive
programs available up till now have been more primitive than those on
the Macintosh or Windows. They are, however, completely free (as
opposed to hundreds of pounds) and the quality is definitely
improving.
In principle it should be possible to put together a complete, usable
Linux system for a visually impaired person for about $500 (cheap &
nasty PC + sound card). This compares with many thousands of dollars
for other operating systems (screen reader software/ speech
synthesiser hardware). I have yet to see this. I doubt it would work
in practice because the software speech synthesisers available for
Linux aren't yet sufficiently good. For a physically disabled person,
the limitation will still be the expense of input hardware.
3. Visually Impaired
I'll use two general categories here. People who are partially
sighted and need help seeing / deciphering / following the text and
those who are unable to use any visual interface whatsoever.
3.1. Seeing the Screen with Low Vision
There are many different problems here. Often magnification can be
helpful, but that's not the full story. Sometimes people can't track
motion, sometimes people can't find the cursor unless it moves. This
calls for a range of techniques, the majority of which are only just
being added to X.
3.1.1. SVGATextMode
This program is useful for improving the visibility of the normal text
screen that Linux provides. The normal screen that Linux provides
shows 80 characters across by 25 vertically. This can be changed (and
the quality of those characters improved) using SVGATextMode. The
program allows full access to the possible modes of an SVGA graphics
card. For example, the text can be made larger so that only 50 by 15
characters appear on the screen. There isn't any easy way to zoom in
on sections of a screen, but you can resize when needed.
3.1.2. X Window System
For people who can see the screen there are a large number of ways of
improving X. They don't add up to a coherent set of features yet, but
if set up correctly could solve many problems.
3.1.2.1. Different Screen Resolutions
The X server can be set up with many different resolutions. A single
key press can then change between them allowing difficult to read text
to be seen.
In the file /etc/XF86Config, you have an entry in the Screen section
with a line beginning with modes. If, for example, you set this to
Modes "1280x1024" "1024x768" "800x600" "640x480" "320x240"
with each mode set up correctly (which requires a reasonably good mon&SHY;
itor for the highest resolution mode), you will be able to have four
times screen magnification, switching between the different levels
using
Ctrl+Alt+Keypad-Plus and Ctrl+Alt+Keypad-Minus
Moving the mouse around the screen will scroll you to different parts
of the screen. For more details on how to set this up you should see
the documentation which comes with the XFree86 X server.
3.1.2.2. Screen Magnification
There are several known screen magnification programs, xmag which will
magnify a portion of the screen as much as needed but is very
primitive. Another one is xzoom. Previously I said that there had to
be something better than xmag, well this is it. See section
``xzoom''.
Another program which is available is puff. This is specifically
oriented towards visually impaired users. It provides such features
as a box around the pointer which makes it easier to locate. Other
interesting features of puff are that, if correctly set up, it is able
to select and magnify portions of the screen as they are updated.
However, there seem to be interacations between xpuff and the window
manager which could make it difficult to use. When used with my fvwm
setup, it didn't respond at all to key presses. However using twm
improved the situation.
The final program which I have seen working is dynamag. This again
has some specific advantages such as the ability to select a specific
area of the screen and monitor it, refreshing the magnified display at
regular intervals between a few tenths of a second at twenty seconds.
dynamag is part of the UnWindows distribution. See ``UnWindows'' for
more details.
3.1.2.3. Change Screen Font
The screen fonts all properly written X software should be changeable.
You can simply make it big enough for you to read. This is generally
accomplished by putting a line the file .Xdefaults which should be in
your home directory. By putting the correct lines in this you can
change the fonts of your programs, for example
Emacs.font: -sony-fixed-medium-r-normal--16-150-75-75-c-80-iso8859-*
To see what fonts are available, use the program xfontsel under X.
There should be some way of changing things at a more fundamental
level so that everything comes out with a magnified font. This could
be done by renaming fonts, and by telling telling font generating
programs to use a different level of scaling. If someone gets this to
work properly, please send me the details of how you did it.
3.1.2.4. Cross Hair Cursors etc..
For people that have problems following cursors there are many things
which can help;
· cross-hair cursors (horizontal and vertical lines from the edge of
the screen)
· flashing cursors (flashes when you press a key)
No software I know of specifically provides a cross hair cursor.
puff, mentioned in the previous section does however provide a
flashing box around the cursor which can make it considerably easier
to locate.
For now the best that can be done is to change the cursor bitmap.
Make a bitmap file as you want it, and another one which is the same
size, but completely black. Convert them to the XBM format and run
xsetroot -cursor cursorfile.xbm black-file.xbm
actually, if you understand masks, then the black-file doesn't have to
be completely black, but start with it like that. The .Xdefaults file
controls cursors used by actual applications. For much more
information, please see the X Big Cursor mini-HOWTO, by Joerg
Schneider <schneid@ira.uka.de>.
3.1.3. Audio
Provided that the user can hear, audio input can be very useful for
making a more friendly and communicative computing environment. For a
person with low vision, audio clues can be used to help locate the
pointer (see ``UnWindows''). For a console mode user using Emacspeak
(see ``Emacspeak''), the audio icons available will provide very many
useful facilities.
Setting up Linux audio is covered in the Linux Sound HOWTO (see
``Linux Documentation''). Once sound is set up, sounds can be played
with the play command which is included with most versions of Linux.
This is the way to use my version of UnWindows.
3.1.4. Producing Large Print
Using large print with Linux is quite easy. There are several
techniques.
3.1.4.1. LaTeX / TeX
LaTeX is an extremely powerful document preparation system. It may be
used to produce large print documents of almost any nature. Though
somewhat complicated to learn, many documents are produced using LaTeX
or the underlying typesetting program, TeX.
this will produce some reasonably large text
\font\magnifiedtenrm=cmr10 at 20pt % setup a big font
\magnifiedtenrm
this is some large text
\bye
For more details, see the LaTeX book which is available in any
computer book shop. There are also a large number of introductions
available on the internet.
3.1.5. Outputting Large Text
Almost all Linux printing uses postscript, and Linux can drive almost
any printer using it. I output large text teaching materials using a
standard Epson dot matrix printer.
For users of X, there are various tools available which can produce
large Text. These include LyX, and many commercial word processors.
3.2. Aids for Those Who Can't Use Visual Output
For someone who is completely unable to use a normal screen there are
two alternatives Braille and Speech. Obviously for people who also
have hearing loss, speech isn't always useful, so Braille will always
be important.
If you can choose, which should you choose? This is a matter of
`vigorous' debate. Speech is rapid to use, reasonably cheap and
especially good for textual applications (e.g. reading a long document
like this one). Problems include needing a quiet environment,
possibly needing headphones to work without disturbing others and
avoid being listened in on by them (not available for all speech
synthesisers).
Braille is better for applications where precise layout is important
(e.g. spreadsheets). Also can be somewhat more convenient if you want
to check the beginning of a sentence when you get to the end. Braille
is, however, much more expensive and slower for reading text.
Obviously, the more you use Braille, the faster you get. Grade II
Braille is difficult to learn, but is almost certainly worth it since
it is much faster. This means that if you don't use Braille for a
fair while you can never discover its full potential and decide for
yourself. Anyway, enough said on this somewhat controversial topic.
based on original by James Bowden <jrbowden@bcs.org.uk>
3.2.1. Braille Terminals
Braille terminals are normally a line or two of Braille. Since these
are at most 80 characters wide and normally 40 wide, they are somewhat
limited. I know of two kinds
· Hardware driven Braille terminals.
· Software driven Braille terminals.
The first kind works only when the computer is in text mode and reads
the screen memory directly. See section ``hardware driven Braille
terminals''.
The second kind of Braille terminal is similar, in many ways, to a
normal terminal screen of the kind Linux supports automatically.
Unfortunately, they need special software to make them usable.
There are two packages which help with these. The first, BRLTTY,
works with several Braille display types and the authors are keen to
support more as information becomes available. Currently BRLTTY
supports Tieman B.V.'s CombiBraille series, Alva B.V.'s ABT3 series
and Telesensory Systems Inc.'s PowerBraille and Navigator series
displays. The use of Blazie Engineering's Braille Lite as a Braille
display is discouraged, but support may be renewed on demand. See
section ``Software Braille Terminals''.
The other package I am aware of is Braille Enhanced Screen. This is
designed to work on other UNIX systems as well as Linux. This should
allow user access to a Braille terminal with many useful features such
as the ability to run different programs in different `virtual
terminals' at the same time.
3.2.2. Speech Synthesis
Speech Synthesisers take (normally) ASCII text and convert it into
actual spoken output. It is possible to have these implemented as
either hardware or software. Unfortunately, the free Linux speech
synthesisers are, reportedly, not good enough to use as a sole means
of output.
Hardware speech synthesisers are the alternative. The main one that I
know of that works is DECtalk from Digital, driven by emacspeak.
However, at this time (March 1997) a driver for the Doubletalk
synthesiser has been announced. Using emacspeak full access to all of
the facilities of Linux is fairly easy. This includes the normal use
of the shell, a world wide web browser and many other similar
features, such as email. Although, it only acts as a plain text
reader (similar to IBM's one for the PC) when controling programs it
doesn't understand, with those that it does, it can provide much more
sophisticated control. See section ``Emacspeak'' for more information
about emacspeak.
3.2.3. Handling Console Output
When it starts up, Linux at present puts all of its messages straight
to the normal (visual) screen. This could be changed if anyone with a
basic level of kernel programming ability wants to do it. This means
that it is impossible for most Braille devices to get information
about what Linux is doing before the operating system is completely
working.
It is only at that stage that you can start the program that you need
for access. If the BRLTTY program is used and run very early in the
boot process, then from this stage on the messages on the screen can
be read. Most hardware and software will still have to wait until the
system is completely ready. This makes administering a Linux system
difficult, but not impossible for a visually impaired person. Once
the system is ready however, you can scroll back by pressing (on the
default keyboard layout) Shift-PageUP.
There is one Braille system that can use the console directly, called
the Braillex. This is designed to read directly from the screen
memory. Unfortunately the normal scrolling of the terminal gets in
the way of this. If you are using a Kernel newer than 1.3.75, just
type linux no-scroll at the LILO prompt or configure LILO to do this
automatically. If you have an earlier version of Linux, see section
``Screen Memory Braille Terminals''
The other known useful thing to do is to use sounds to say when each
stage of the boot process has been reached. (T.V. Raman suggestion)
3.2.4. Optical Character Recognition
There is a free Optical Character Recognition (OCR) program for Linux
called xocr. In principle, if it is good enough, this program would
allow visually impaired people to read normal books to some extent
(accuracy of OCR is never high enough..). However, according to the
documentation, this program needs training to recognise the particular
font that it is going to use and I have no idea how good it is since I
don't have the hardware to test it.
3.3. Beginning to Learn Linux
Beginning to learn Linux can seem difficult and daunting for someone
who is either coming from no computing background or from a pure DOS
background. Doing the following things may help:
· Learn to use Linux (or UNIX) on someone else's system before
setting up your own.
· Initially control Linux from your own known speaking/Braille
terminal. If you plan to use speech, you may want to learn emacs
now. You can learn it as you go along though. See below
· If you come from an MS-DOS background, read the DOS2Linux Mini
HOWTO for help with converting (see ``The Linux HOWTO Documents'').
The Emacspeak HOWTO written by Jim Van Zandt (<jrv@vanzandt.mv.com>)
covers this in much more detail (see ``The Linux HOWTO Documents'').
If you are planning to use Emacspeak, you should know that Emacspeak
does not attempt to teach Emacs, so in this sense, prior knowledge of
Emacs would always be useful. This said, you certainly do not need to
know much about Emacs to start using Emacspeak. In fact, once
Emacspeak is installed and running, it provides a fluent interface to
the rich set of online documentation including the info pages, and
makes learning what you need a lot easier.
"In summary: starting to use Emacspeak takes little learning. Getting
the full mileage out of Emacs and Emacspeak, especially if you intend
using it as a replacement for X Windows as I do does involve
eventually becoming familiar with a lot of the Emacs extensions; but
this is an incremental process and does not need to be done in a day."
- T.V.Raman
One other option which may be interesting are the RNIB training tapes
which include one covering UNIX. These can be got from
RNIB
Customer Services
PO Box 173
Peterborough
Cambridgeshire PE2 6WS
Tel: 01345 023153 (probably only works in UK)
3.4. Braille Embossing
Linux should be the perfect platform to drive a Braille embosser from.
There are many formatting tools which are aimed specifically at the
fixed width device. A Braille embosser can just be connected to the
serial port using the standard Linux printing mechanisms. For more
info see the Linux Printing HOWTO.
There is a free software package which acts as a multi-lingual grade
two translator available for Linux from the American ``National
Federation for the Blind''. This is called NFBtrans. See section
``NFB translator'' for more details.
4. Hearing Problems
For the most part there is little problem using a computer for people
with hearing problems. Almost all of the output is visual. There are
some situations where sound output is used though. For these, the
problem can sometimes be worked round by using visual output instead.
4.1. Visual Bells
By tradition, computers go `beep' when some program sends them a
special code. This is generally used to get attention to the program
and for little else. Most of the time, it's possible to replace this
by making the entire screen (or terminal emulator) flash. How to do
this is very variable though.
xterm (under X)
for xterm, you can either change the setting by pressing the
middle mouse button while holding down the control key, or by
putting a line with just `XTerm*visualBell: true' (not the
quotes of course) in the file .Xdefaults in your home directory.
the console (otherwise)
The console is slightly more complex. Please see Alessandro
Rubini's Visual Bell mini HOWTO for details on this. Available
along with all the other Linux documentation (see section
``other Linux documents''). Mostly the configuration has to be
done on a per application basis, or by changing the Linux Kernel
its self.
5. Physical Problems
Many of these problems have to be handled individually. The needs of
the individual, the ways that they can generate input and other
factors vary so much that all that this HOWTO can provide is a general
set of pointers to useful software and expertise.
5.1. Unable to Use a Mouse/Pointer
Limited mobility can make it difficult to use a mouse. For some
people a tracker ball can be a very good solution, but for others the
only possible input device is a keyboard (or even something which
simulates a keyboard). For normal use of Linux this shouldn't be a
problem (but see the section ``Making the keyboard behave''), but for
users of X, this may cause major problems under some circumstances.
Fortunately, the fvwm window manager has been designed for use without
a pointer and most things can be done using this. I actually do this
myself when I lose my mouse (don't ask) or want to just keep typing.
fvwm is included with all distributions of Linux that I know of.
Actually using other programs will depend on their ability to accept
key presses. Many X programs do this for all functions. Many don't.
I sticky mouse keys, which are supposedly present in the current
release of X should make this easier.
5.1.1. Unable to Use a Keyboard
People who are unable to use a keyboard normally can sometimes use one
through a headstick or a mouthstick. This calls for special setup of
the keyboard. Please see also the section ``Making the keyboard
behave''.
5.1.1.1. Other Input Hardware (X Windows System only)
For others, the keyboard cannot be used at all and only pointing
devices are available. In this case, no solution is available under
the standard Linux Console and X will have to be used. If the X-Input
extension can be taught to use the device and the correct software for
converting pointer input to characters can be found (I haven't seen it
yet) then any pointing should be usable without a keyboard.
There are a number of devices worth considering for such input such as
touch screens and eye pointers. Many of these will need a `device
driver' written for them. This is not terribly difficult if the
documentation is available, but requires someone with good C
programming skills. Please see the Linux Kernel Hackers guide and
other kernel reference materials for more information. Once this is
set up, it should be possible to use these devices like a normal
mouse.
5.1.2. Controlling Physical Hardware From Linux
The main group of interest here are the Linux Lab Project. Generally,
much GPIB (a standard interface to scientific equipment, also known as
the IEEE bus) hardware can be controlled. This potentially gives much
potential for very ambitious accessibility projects. As far as I know
none have yet been attempted.
5.2. Speech Recognition
Speech recognition is a very powerful tool for enabling computer use.
There are two recognition systems that I know of for Linux, the first
is ears which is described as ``recognition is not optimal. But it is
fine for playing and will be improved'', the second is AbbotDemo ``A
speaker independent continuous speech recognition system'' which may
well be more interesting, though isn't available for commercial use
without prior arrangement. See the Linux software map for details
(see section ``other Linux documents'').
5.3. Making the Keyboard Behave
5.3.1. X Window System.
The latest X server which comes with Linux can include many features
which assist in input. This includes such features as StickKeys,
MouseKeys, RepeatKeys, BounceKeys, SlowKeys, and TimeOut. These allow
customisation of the keyboard to the needs of the user. These are
provided as part of the XKB> extension in versions of X after version
6.1. To find out your version and see whether you have the extension
installed, you can try.
xdpyinfo -queryExtensions
5.3.2. Getting Rid of Auto Repeat
To turn off key repeat on the Linux console run this command (I think
it has to be run once per console; a good place to run it would be in
your login files, .profile or .login in your home directory).
setterm -repeat off
To get rid of auto repeat on any X server, you can use the command
xset -r
which you could put into the file which get runs when you start using
X (often .xsession or .xinit under some setups)
Both of these commands are worth looking at for more ways of changing
behaviour of the console.
5.3.3. Macros / Much input, few key presses
Often in situations such as this, the biggest problem is speed of
input. Here the most important thing to aim for is the most number of
commands with the fewest key presses. For users of the shell (bash /
tcsh) you should look at the manual page, in particular command and
filename completion (press the tab key and bash tries to guess what
should come next). For information on macros which provide sequences
of commands for just one key press, have a look at the Keystroke
HOWTO.
5.3.4. Sticky Keys
Sticky keys are a feature that allow someone who can only reliably
press one button at a time to use a keyboard with all of the various
modifier keys such as shift and control. These keys, instead of
having to be held on at the same time as the other key instead become
like the caps lock key and stay on while the other key is pressed.
They may then either switch off or stay on for the next key depending
on what is needed. For information about how to set this up please
see the Linux Keyboard HOWTO, especially section `I can use only one
finger to type with' (section 15 in the version I have) for more
information on this. - Information from Toby Reed.
6. General Programming Issues
Many of the issues worth taking into account are the same when writing
software which is designed to be helpful for access as when trying to
follow good design.
6.1. Try to Make it Easy to Provide Multiple Interfaces
If your software is only usable through a graphical interface then it
can be very hard to make it usable for someone who can't see. If it's
only usable through a line oriented interface, then someone who can't
type will have difficulties.
Provide keyboard shortcuts as well as the use of the normal X pointer
(generally the mouse). You can almost certainly rely on the user
being able to generate key presses to your application.
6.2. Make software configurable.
If it's easy to change fonts then people will be able to change to one
they can read. If the colour scheme can be changed then people who
are colour blind will be more likely to be able to use it. If fonts
can be changed easily then the visually impaired will find your
software more useful.
6.3. Test the Software on Users.
If you have a number of people use your software, each with different
access problems then they will be more likely to point up specific
problems. Obviously, this won't be practical for everybody, but you
can always ask for feedback.
6.4. Make Output Distinct
Where possible, make it clear what different parts of your program are
what. Format error messages in a specific way to identify them.
Under X, make sure each pane of your window has a name so that any
screen reader software can identify it.
6.5. Licenses
Some software for Linux (though none of the key programs) has license
like `not for commercial use'. This could be quite bad for a person
who starts using the software for their personal work and then
possibly begins to be able to do work they otherwise couldn't with it.
This could be something which frees them from financial and other
dependence on others people. Even if the author of the software is
willing to make exceptions, it makes the user vulnerable both to
changes of commercial conditions (some company buys up the rights) and
to refusal from people they could work for (many companies are overly
paranoid about licenses). It is much better to avoid this kind of
licensing where possible. Protection from commercial abuse of
software can be obtained through more specific licenses like the GNU
Public License or Artistic License where needed.
7. Other Information
7.1. Linux Documentation
The Linux documentation is critical to the use of Linux and most of
the documents mentioned here should be included in recent versions of
Linux, from any source I know of.
If you want to get the documentation on the Internet, here are some
example sites. These should be mirrored at most of the major FTP
sites in the world.
· ftp.funet.fi (128.214.6.100) : /pub/OS/Linux/doc/
· tsx-11.mit.edu (18.172.1.2) : /pub/linux/docs/
· sunsite.unc.edu (152.2.22.81) : /pub/Linux/docs/
7.1.1. The Linux Info Sheet
A simple and effective explanation of what Linux is. This is one of
the things that you should hand over when you want to explain why you
want Linux and what it is good for.
The Linux Info Sheet is available on the World Wide Web from
<http://sunsite.unc.edu/mdw/HOWTO/INFO-SHEET.html> and other mirrors.
7.1.2. The Linux Meta FAQ
A list of other information resources, much more complete than this
one. The meta FAQ is available on the World Wide Web from
<http://sunsite.unc.edu/mdw/HOWTO/META-FAQ.html> and other mirrors
7.1.3. The Linux Software Map
The list of software available for Linux on the Internet. Many of the
packages listed here were found through this. The LSM is available in
a searchable form from <http://www.boutell.com/lsm/>. It is also
available in a single text file in all of the FTP sites mentioned in
section ``Linux Documentation''.
7.1.4. The Linux HOWTO documents
The HOWTO documents are the main documentation of Linux. This Access
HOWTO is an example of one.
The home site for the Linux Documentation Project which produces this
information is <http://sunsite.unc.edu/mdw/linux.html>. There are
also many companies producing these in book form. Contact a local
Linux supplier for more details.
The Linux HOWTO documents will be in the directory HOWTO in all of the
FTP sites mentioned in section ``Linux Documentation''.
7.1.5. The Linux FAQ
A list of `Frequently Asked Questions' with answers which should solve
many common questions. The FAQ list is available from
<http://www.cl.cam.ac.uk/users/iwj10/linux-faq/> as well as all of the
FTP sites mentioned in section ``Linux Documentation''.
7.2. Mailing Lists
There are two lists that I know of covering these issues specifically
for Linux. There are also others which it is worth researching which
cover computer use more generally. Incidentally, if a mail is sent to
these lists I will read it eventually and include any important
information in the Access-HOWTO, so you don't need to send me a
separate copy unless it's urgent in some way.
7.2.1. The Linux Access List
This is a general list covering Linux access issues. It is designed
`to service the needs of users and developers of the Linux OS and
software who are either disabled or want to help make Linux more
accessible'. To subscribe send email to
<majordomo@ssv1.union.utah.edu> and in the BODY (not the subject) of
the email message put:
subscribe linux-access <your-email-address>
7.2.2. The Linux Blind List
This is a mailing list covering Linux use for blind users. There is
also a list of important and useful software being gathered in the
list's archive. To subscribe send mail to <blinux-list-
request@redhat.com> with the subject: help. This list is now
moderated.
7.3. WWW References
The World Wide Web is, by it's nature, very rapidly changing. If you
are reading this document in an old version then some of these are
likely to be out of date. The original version that I maintain on the
WWW shouldn't go more than a month or two out of date, so refer to
that please.
Linux Documentation is available from
<http://sunsite.unc.edu/mdw/linux.html>
Linux Access On the Web <http://www.tardis.ed.ac.uk/~mikedlr/access/>
with all of the versions of the HOWTO in
<http://www.tardis.ed.ac.uk/~mikedlr/access/HOWTO/>. Preferably,
however, download from one of the main Linux FTP sites. If I get a
vast amount of traffic I'll have to close down these pages and move
them elsewhere.
The BLINUX Documentation and Development Project
<http://leb.net/blinux/>. "The purpose of The BLINUX Documentation
and Development Project is to serve as a catalyst which will both spur
and speed the development of software and documentation which will
enable the blind user to run his or her own Linux workstation."
Emacspeak WWW page
<http://cs.cornell.edu/home/raman/emacspeak/emacspeak.html>
BRLTTY unofficial WWW page
<http://www.sf.co.kr/t.linux/new/brltty.html>
Yahoo (one of the most major Internet catalogues)
<http://www.yahoo.com/Society_and_Culture/Disabilities/Adaptive_Technology/>
The Linux Lab Project <http://www.fu-berlin.de/~clausi/>.
The BLYNX pages: Lynx Support Files Tailored For Blind and Visually
Handicapped Users <http://leb.net/blinux/blynx/>.
7.4. Suppliers
This is a UK supplier for the Braillex.
Alphavision Limited
7.5. Manufacturers
7.5.1. Alphavision
I think that they are a manufacturer? RNIB only lists them as a
supplier, but others say they make the Braillex.
Alphavision Ltd
Seymour House
Copyground Lane
High Wycombe
Bucks HP12 3HE
England
U.K.
Phone
+44 1494-530 555
7.5.1.1. Linux Supported Alphavision AT Products
· Braillex
7.5.2. Blazie Engineering
The Braille Lite was supported in the original version of BRLTTY.
That support has now been discontinued. If you have one and want to
use it with Linux then that may be possible by using this version of
the software.
Blazie Engineering
105 East Jarrettsville Rd.
Forest Hill, MD 21050
U.S.A.
Phone
+1 (410) 893-9333
FAX
+1 (410) 836-5040
BBS
+1 (410) 893-8944
<info@blazie.com>
WWW
<http://www.blazie.com/>
7.5.2.1. Blazie AT Products
· Braille Lite (support discontinued)
7.5.3. Digital Equipment Corporation
Digital Equipment Corporation
P.O. Box CS2008
Nashua
NH 03061-2008
U.S.A
Order
+1 800-722-9332
Tech info
+1 800-722-9332
FAX
+1 603-884-5597
WWW
<http://www.digital.com/>
7.5.3.1. Linux Supported DEC AT Products
· DECTalk Express
7.5.4. Kommunikations-Technik Stolper GmbH
KTS Stolper GmbH
Herzenhaldenweg 10
73095 Albershausen
Germany
Phone
+49 7161 37023
Fax
+49 7161 32632
7.5.4.1. Linux Supported KTG AT Products
· Brailloterm
8. Software Packages
References in this section are taken directly from the Linux Software
map which can be found in all standard places for Linux documentation
and which lists almost all of the software available for Linux.
8.1. Emacspeak
Emacspeak is the software side of a speech interface to Linux. Any
other character based program, such as a WWW browser, or telnet or
another editor can potentially be used within emacspeak. The main
difference between it and normal screen reader software for such
operating systems as DOS is that it also has a load more extra
features. It is based in the emacs text editor.
A text editor is generally just a program which allows you to change
the contents of a file, for example, adding new information to a
letter. Emacs is in fact far beyond a normal text editor, and so this
package is much more useful than you might imagine. You can run any
other program from within emacs, getting any output it generates to
appear in the emacs terminal emulator.
The reason that emacs is a better environment for Emacspeak is that it
can can understand the layout of the screen and can intelligently
interpret the meaning of, for example, a calendar, which would just be
a messy array of numbers otherwise. The originator of the package
manages to look after his own Linux machine entirely, doing all of the
administration from within emacs. He also uses it to control a wide
variety of other machines and software directly from that machine.
Emacspeak is included within the Debian Linux distribution and is
included as contributed software within the Slakware distribution.
This means that it is available on many of the CDROM distributions of
Linux. By the time this is published, the version included should be
5 or better, but at present I only have version 4 available for
examination.
Begin3
Title: emacspeak - a speech output interface to Emacs
Version: 4.0
Entered-date: 30MAY96
Description: Emacspeak is the first full-fledged speech output
system that will allow someone who cannot see to work
directly on a UNIX system. (Until now, the only option
available to visually impaired users has been to use a
talking PC as a terminal.) Emacspeak is built on top
of Emacs. Once you start emacs with emacspeak loaded,
you get spoken feedback for everything you do. Your
mileage will vary depending on how well you can use
Emacs. There is nothing that you cannot do inside
Emacs:-)
Keywords: handicap access visually impaired blind speech emacs
Author: raman@adobe.com (T. V. Raman)
Maintained-by: jrv@vanzandt.mv.com (Jim Van Zandt)
Primary-site: sunsite.unc.edu apps/sound/speech
124kB emacspeak-4.0.tgz
Alternate-site:
Original-site: http://www.cs.cornell.edu /pub/raman/emacspeak
123kB emacspeak.tar.gz/Info/People/raman/emacspeak/emacspeak.tar.gz
Platforms: DECtalk Express or DEC Multivoice speech synthesizer,
GNU FSF Emacs 19 (version 19.23 or later) and TCLX
7.3B (Extended TCL).
Copying-policy: GPL
End
8.2. BRLTTY
This is a program for running a serial port Braille terminal. It has
been widely tested and used, and supports a number of different kinds
of hardware (see the Linux Software Map entry below).
The maintainer is, Nikhil Nair <nn201@cus.cam.ac.uk>. The other
people working on it are Nicolas Pitre <nico@cam.org> and Stephane
Doyon <doyons@jsp.umontreal.ca>. Send any comments to all of them.
The authors seem keen to get support in for more different devices, so
if you have one you should consider contacting them. They will almost
certainly need programming information for the device, so if you can
contact your manufacturer and get that they are much more likely to be
able to help you.
A brief feature list (from their README file) to get you interested
· Full implementation of the standard screen review facilities.
· A wide range of additional optional features, including blinking
cursor and capital letters, screen freezing for leisurely review,
attribute display to locate highlighted text, hypertext links, etc.
· `Intelligent' cursor routing. This allows easy movement of the
cursor in text editors etc. without moving the hands from the
Braille display.
· A cut & paste function. This is particularly useful for copying
long filenames, complicated commands etc.
· An on-line help facility.
· Support for multiple Braille codes.
· Modular design allows relatively easy addition of drivers for other
Braille displays, or even (hopefully) porting to other Unix-like
platforms.
Begin3
Title: BRLTTY - Access software for Unix for a blind person
using a soft Braille terminal
Version: 1.0.2, 17SEP96
Entered-date: 17SEP96
Description: BRLTTY is a daemon which provides access to a Unix console
for a blind person using a soft Braille display (see the
README file for a full explanation).
BRLTTY only works with text-mode applications.
We hope that this system will be expanded to support
other soft Braille displays, and possibly even other
Unix-like platforms.
Keywords: Braille console access visually impaired blind
Author: nn201@cus.cam.ac.uk (Nikhil Nair)
nico@cam.org (Nicolas Pitre)
doyons@jsp.umontreal.ca (Stephane Doyon)
jrbowden@bcs.org.uk (James Bowden)
Maintained-by: nn201@cus.cam.ac.uk (Nikhil Nair)
Primary-site: sunsite.unc.edu /pub/Linux/system/Access
110kb brltty-1.0.2.tar.gz (includes the README file)
6kb brltty-1.0.2.README
1kb brltty-1.0.2.lsm
Platforms: Linux (kernel 1.1.92 or later) running on a PC or DEC Alpha.
Not X/graphics.
Supported Braille displays (serial communication only):
- Tieman B.V.: CombiBraille 25/45/85;
- Alva B.V.: ABT3xx series;
- Telesensory Systems Inc.: PowerBraille 40 (not 65/80),
Navigator 20/40/80 (latest firmware version only?).
Copying-policy: GPL
End
8.3. Screen
Screen is a standard piece of software to allow many different
programs to run at the same time on one terminal. It has been
enhanced to support some Braille terminals (those from Telesensory)
directly.
8.4. Rsynth
This is a speech synthesiser listed in the Linux Software Map. It
doesn't apparently work well enough for use by a visually impaired
person. Use hardware instead, or improve it.. a free speech
synthesiser would be really really useful.
8.5. xocr
xocr is a package which implements optical character recognition for
Linux. As with Rsynth, I don't think that this will be acceptable as
a package for use as a sole means of input by a visually impaired
person. I suspect that the algorithm used means that it will need to
be watched over by someone who can check that it is reading correctly.
I would love to be proved wrong.
8.6. xzoom
xzoom is a screen magnifier, in the same vein as xmag, but
sufficiently better to be very useful to a visually impaired person.
The main disadvantages of xzoom are that it can't magnify under
itself, that some of the key controls aren't compatible with fvwm, the
normal Linux window manager and that it's default configuration
doesn't run over a network (this can be fixed at some expense to
speed). Apart from that though, it's excellent. It does continuous
magnification which allows you to, for example, scroll a document up
and down, whilst keeping the section you are reading magnified.
Alternatively, you can move a little box around the screen, magnifying
the contents and letting you search for the area you want to see.
xzoom is also available as an rpm from the normal RedHat sites, making
it very easy to install for people using the rpm system (such as
Redhat users).
Begin3
Title: xzoom
Version: 0.1
Entered-date: Mar 30 1996
Description: xzoom can magnify (by integer value) rotate
(by a multiple if 90 degrees) and mirror about
the X or Y axes areas on X11 screen
and display them in it's window.
Keywords: X11 zoom magnify xmag
Author: Itai Nahshon <nahshon@best.com>
Maintained-by: Itai Nahshon <nahshon@best.com>
Primary-site: sunsite.unc.edu
probably in /pub/Linux/X11/xutils/xzoom-0.1.tgz
Platforms: Linux+11. Support only for 8-bit depth.
Tested only in Linux 1.3.* with the XSVGA 3.1.2
driver.
Needs the XSHM extension.
Copying-policy: Free
End
8.7. NFBtrans
nfbtrans is a multi-grade Braille translation program distributed by
the National Federation for the Blind in the U.S.A. It is released
for free in the hope that someone will improve it. Languages covered
are USA English, UK English, Spanish, Russian, Esperanto, German,
Biblical Hebrew and Biblical Greek, though others could be added just
by writing a translation table. Also covered are some computer and
math forms. I have managed to get it to compile under Linux, though,
not having a Braille embosser available at the present moment I have
not been able to test it.
NFBtrans is available from <ftp://nfb.org/ftp/nfb/braille/nfbtrans/>.
After downloading it, you will have to compile it.
8.7.1. Compiling NFBtrans on Linux
I have returned this patch to the maintainer of NFBtrans and he says
that he has included it, so if you get a version later than 740, you
probably won't have to do anything special. Just follow the
instructions included in the package.
unzip -L NFBTR740.ZIP #or whatever filename you have
mv makefile Makefile
Next save the following to a file (e.g. patch-file)
*** nfbpatch.c.orig Tue Mar 12 11:37:28 1996
--- nfbpatch.c Tue Mar 12 11:37:06 1996
***************
*** 185,190 ****
--- 185,193 ----
return (finfo.st_size);
} /* filelength */
+ #ifndef linux
+ /* pretty safe to assume all linux has usleep I think ?? this should be
+ done properly anyway */
#ifdef SYSVR4
void usleep(usec)
int usec;
***************
*** 195,200 ****
--- 198,204 ----
UKP } /* usleep */
#endif
+ #endif
void beep(count)
int count;
and run
patch < patch-file
then type
make
and the program should compile.
8.8. UnWindows
UnWindows is a package of access utilities for X which provides many
useful facilities for the visually impaired (not blind). It includes
a screen magnifier and other customised utilities to help locate the
pointer. UnWindows can be downloaded from
<ftp://ftp.cs.rpi.edu/pub/unwindows>.
As it comes by default, the package will not work on Linux because it
relies on special features of Suns. However, some of the utilities do
work and I have managed to port most of the rest so this package may
be interesting to some people. My port will either be incorporated
back into the original or will be available in the BLINUX archives
(see ``WWW references''). The remaining utility which doesn't yet
work is the configuration utility.
In my version the programs, instead of generating sounds themselves,
just call another program. The other program could for example be
play /usr/lib/games/xboing/sounds/ouch.au
Which would make the xboing ouch noise, for example it could do this
as the pointer hit the left edge of the screen.
8.8.1. dynamag
dynamag is a screen magnification program. please see the section on
Screen magnification (``magnification''). This program worked in the
default distribution.
8.8.2. coloreyes
coloreyes makes it easy to find the pointer (mouse) location. It
consists of a pair of eyes which always look in the direction of the
pointer (like xeyes) and change color depending on how far away the
mouse is (unlike xeyes). This doesn't work in the default
distribution, but the test version, at the same location, seems to
work.
8.8.3. border
border is a program which detects when the pointer (mouse) has moved
to the edge of the screen and makes a sound according to which edge of
the screen has been approached. The version which is available uses a
SUN specific sound system. I have now changed this so that instead of
that, it just runs a command, which could be any Linux sound program.
8.8.4. un-twm
The window manager is a special program which controls the location of
all of the other windows (programs) displayed on the X screen. un-twm
is a special version which will make a sound as the pointer enters
different windows. The sound will depend on what window has been
entered. The distributed version doesn't work on linux because, like
border it relies on SUN audio facilities. Again I already have a
special version which will be avaliable by the time you read this.
9. Hardware
9.1. Braille terminals driven from Screen Memory
These are Braille terminals that can read the screen memory directly
in a normal text mode. It is possible to use it to work with Linux
for almost all of the things that a seeing user can do on the console,
including installation. However, it has a problem with the scrolling
of the normal Linux kernel, so a kernel patch needs to be applied.
See ``Patching the Kernel for Braillex and Brailloterm''.
9.1.1. Braillex
The Braillex is a terminal which is designed to read directly from the
Screen memory, thus getting round any problems with MS-DOS programs
which don't behave strangely. If you could see it on screen, then
this terminal should be able to display it in Braille. In Linux,
unfortunately, screen handling is done differently from MS-DOS, so
this has to be changed somewhat.
To get this terminal to work, you have to apply the patch given below
in section ``Patching the Kernel''. Once this is done, the Braillex
becomes one of the most convenient ways to use Linux as it allows all
of the information normally available to a seeing person to be read.
Other terminals don't start working until the operating system has
completely booted.
The Braillex is available with two arrangements of Braille cells (80x1
or 40x2) and there is a model, called the IB 2-D which also has a
vertical bar to show information about all of the lines of the screen
(using 4 programmable dots per screen line)
Price: 8,995 (pounds sterling) or 11495 UKP for 2-D
Manufacturer: Alphavision Limited (UK)
Suppliers: ????
9.1.2. Brailloterm
``What is Brailloterm?
It's a refreshable display Braille, made by KTS Kommunikations-Technik
Stolper GmbH. It has 80 Braille cells in an unique line. Each cell
has 8 dots that are combined (up/down) to represent a character. By
default, Brailloterm shows me the line in which the screen cursor is.
I can use some functions in Brailloterm to see any line in the
screen.'' - Jose Vilmar Estacio de Souza <jvilmar@embratel.net.br>
Jose then goes on to say that the terminal can also use the serial
port under DOS but that it needs a special program. I don't know if
any of the ones for Linux would work.
As with Braillex, this needs a special patch to the kernel work
properly. See section ``Patching the Kernel''.
Price: about 23.000,- DM / $ 15.000,
Manufacturer: Kommunikations-Technik Stolper GmbH
Suppliers: ????
9.1.3. Patching the Kernel for Braillex and Brailloterm
This probably also applies to any other terminals which read directly
from screen memory to work under MS-DOS. Mail me to confirm any
terminals that you find work. This does not apply and will actually
lose some features for terminals driven using the BRLTTY software.
I am told this patch applies to all Kernels version 1.2.X. It should
also work on all Kernel versions from 1.1.X to 1.3.72, with just a
warning from patch (I've tested that the patch applies to 1.3.68 at
least). From 1.3.75 the patch is no longer needed because the Kernel
can be configured not to scroll using `linux no-scroll' at the LILO
prompt. See the Boot Prompt HOWTO for more details.
*** drivers/char/console.c~ Fri Mar 17 07:31:40 1995
--- drivers/char/console.c Tue Mar 5 04:34:47 1996
***************
*** 601,605 ****
static void scrup(int currcons, unsigned int t, unsigned int b)
{
! int hardscroll = 1;
if (b > video_num_lines || t >= b)
--- 601,605 ----
static void scrup(int currcons, unsigned int t, unsigned int b)
{
! int hardscroll = 0;
if (b > video_num_lines || t >= b)
To apply it:
1. Save the above text to a file (say patch-file)
2. change to the drivers/char directory of your kernel sources
3. run
patch < patch-file
4. Compile your kernel as normal
Apply those patches and you should be able to use the Braille terminal
as normal to read the Linux Console.
Put in words, the patch just means `change the 1 to a 0 in the first
line of the function scrup which should be near line 603 in the file
drivers/char/console.c'. The main thing about patch is that program
understands this, and that it knows how to guess what to do when the
Linux developers change things in that file.
If you want to use a more modern kernel with completely disabled
scrolling, (instead of the boot prompt solution I already mentioned),
please use the following patch. This does not apply to kernels
earlier than 1.3.75.
*** console.c~ Fri Mar 15 04:01:45 1996
--- console.c Thu Apr 4 13:29:48 1996
***************
*** 516,520 ****
unsigned char has_wrapped; /* all of videomem is data of fg_console */
static unsigned char hardscroll_enabled;
! static unsigned char hardscroll_disabled_by_init = 0;
void no_scroll(char *str, int *ints)
--- 516,520 ----
unsigned char has_wrapped; /* all of videomem is data of fg_console */
static unsigned char hardscroll_enabled;
! static unsigned char hardscroll_disabled_by_init = 1;
void no_scroll(char *str, int *ints)
9.2. Software Driven Braille Terminals
The principle of operation of these terminal is very close to that of
a CRT terminal such as the vt100. They connect to the serial port and
the computer has to run a program which sends them output. At present
there are two known programs for Linux. BRLTTY, see section
``BRLTTY'') and Braille enhanced screen.
9.2.1. Tieman B.V.
9.2.1.1. CombiBraille
This Braille terminal is supported by the BRLTTY software. It comes
in three versions with 25, 45 or 85 Braille cells. The extra five
cells over a standard display are used for status information.
Price: around 4600 UKP for the 45 cell model ...
Manufacturer: Tieman B.V.
Suppliers: Concept Systems, Nottingham, England (voice +44 115 925 5988)
9.2.2. Alva B.V.
The ABT3xx series is supported in BRLTTY. Only the ABT340 has been
confirmed to work at this time. Please pass back information to the
BRLTTY authors on other models.
Price: 20 cell - 2200 UKP; 40 cell 4500 UKP; 80 cell 8000 UKP
Manufacturer: Alva
Suppliers: Professional Vision Services LTD, Hertshire, England
(+44 1462 677331)
9.2.3. Telesensory Systems Inc. displays
Because they have provided programming information to the developers,
the Telesensory displays are supported both by BRLTTY and screen.
9.2.3.1. Powerbraille
There are three models the 40, the 65 and the 80. Only the 40 is
known to be supported by BRLTTY.
Price: 20 cell - 2200 UKP; 40 cell 4500 UKP; 80 cell 8000 UKP
Manufacturer: Alva
Suppliers: Professional Vision Services LTD, Hertshire, England
(+44 1462 677331)
9.2.3.2. Navigator
Again there are three models the 20, the 60 and the 80. Recent
versions are all known to work with BRLTTY but whether earlier ones
(with earlier firmware) also work has not been confirmed.
Price: 80 cell 7800 UKP
Manufacturer: Alva
Suppliers: Professional Vision Services LTD, Hertshire, England
(+44 1462 677331)
9.2.4. Braille Lite
This is more a portable computer than a terminal. It could, however,
be used with BRLTTY version 0.22 (but not newer versions) as if it was
a normal Braille terminal. Unfortunately, many of the features
available with the CombiBraille cannot be used with the Braille Lite.
This means that it should be avoided for Linux use where possible.
Price: $3,395.00
Manufacturer: Blazie Engineering
9.3. Speech Synthesisers
Speech synthesisers normally connect to the serial port of a PC.
Useful features include
· Braille labels on parts
· Many voices to allow different parts of document to be spoken
differently
· Use with headphones (not available on all models)
The critical problem is that the quality of the speech. This is much
more important to someone who is using the speech synthesiser as their
main source of information than to someone who is just getting neat
sounds out of a game. For this reason T.V. Raman seems to only
recommend the DECTalk. Acceptable alternatives would be good.
9.3.1. DECTalk Express
This is a hardware speech synthesiser. It is recommended for use with
Emacspeak and in fact the DECTalk range are the only speech
synthesisers which work with that package at present. This
synthesiser has every useful feature that I know about. The only
disadvantage that I know of at present is price.
Price: $1195.00
Manufacturer: Digital Equipment Corporation
Suppliers: Many. I'd like details of those with Specific Linux
support / delivering international or otherwise of note only
please. Otherwise refer to local organisations.
Digital themselves or the Emacspeak WWW pages.
9.3.2. Accent SA
This is a synthesiser made by Aicom Corporation. An effort has begun
to write a driver for it however help is needed. Please see
<http://www.cyberspc.mb.ca/~astrope/speak.html> if you think you can
help.
9.3.3. SPO256-AL2 Speak and Spell chip.
Some interest has been expressed in using this chip in self built
talking circuits. I'd be interested to know if anyone has found this
useful. A software package speak-0.2pl1.tar.gz was produced by David
Sugar <dyfet@tycho.com>. My suspicion, though, is that the quality of
the output wouldn't be good enough for regular use.
10. Acknowledgements
Much of this document was created from various information sources on
the Internet, many found from Yahoo and DEC's Alta Vista Search
engine. Included in this was the documentation of most of the
software packages mentioned in the text. Some information was also
gleaned from the Royal National Institute for the Blind's helpsheets.
T.V. Raman, the author of Emacspeak has reliably contributed comments,
information and text as well as putting me in touch with other people
who he knew on the Internet.
Kenneth Albanowski <kjahds@kjahds.com> provided the patch needed for
the Brailloterm and information about it.
Roland Dyroff of S.u.S.E. GmbH (Linux distributors and makers of
S.u.S.E. Linux (English/German)) looked up KTS Stolper GmbH at my
request and got some hardware details and information on the
Brailloterm.
The most major and careful checks over of this document were done by
James Bowden, <jrbowden@bcs.org.uk> and Nikhil Nair
<nn201@cus.cam.ac.uk>, the BRLTTY authors who suggested a large number
of corrections as well as extra information for some topics.
The contributors to the blinux and linux-access mailing lists have
contributed to this document by providng information for me to read.
Mark E. Novak of the Trace R&D centre <http://trace.wisc.edu/> pointed
me in the direction of several packages of software and information
which I had not seen before. He also made some comments on the
structure of the document which I have partially taken into account
and should probably do more about.
Other contributors include Nicolas Pitrie and Stephane Doyon.
A number of other people have contributed comments and information.
Specific contributions are acknowledged within the document.
This version was specifically produced for RedHat's Dr. Linux book.
This is because they provided warning of it's impending release to
myself and other LDP authors. Their doing this is strongly
appreciated since wrong or old information sits around much longer in
a book than on the Internet.
No doubt you made a contribution and I haven't mentioned it. Don't
worry, it was an accident. I'm sorry. Just tell me and I will add
you to the next version.
| HowTo Linux | Linux Zone Home | E-Mail Me | Copyright 1999 Linux Zone
