Linux Access HOWTO
Michael De La Rue, access-howto@ed.ac.uk
v2.8, 4 May 1996

The Linux Access HOWTO covers the use of adaptive technology with
Linux, In particular, using adaptive technology to make Linux accessi�
ble to those who could not use it otherwise. It also covers areas
where Linux can be used within more general adaptive technology solu�
tions.

1. Introduction

The aim of this document is to collect all information on the use of
Linux by people who have any special difficulty using it which can be
overcome with specific aids, either in software or hardware. In other
words, 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 biggest problem is that, right now, very few of such people are
using Linux due to the difficulties involved among other things. This
means that development is not taking account of special needs and so
the system is becoming more difficult to use. I hope this HOWTO will
solve that problem.

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.

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

A verbatim copy may be reproduced or distributed in any medium physi�
cal or electronic without permission of the author. Translations are
similarly permitted without express permission if it includes a notice
on who translated it.

Short quotes may be used without prior consent by the author. Deriva�
tive work and partial distributions of the UUCP-HOWTO must be accompa�
nied with either a verbatim copy of this file or a pointer to the ver�
batim copy.

Commercial redistribution is allowed and encouraged; however, the
author would appreciate being notified of any such distributions (as a
courtesy).

In short, we wish to promote dissemination of this information through
as many channels as possible. However, we do wish to retain copyright
on the HOWTO documents.

We further want that ALL information provided in the HOWTOs is dissem�
inated. If you have questions, please contact Greg Hankins, the Linux
HOWTO coordinator, at gregh@sunsite.unc.edu.

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.

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 handicapped, 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 would make it practical to
use as a multi-tasking operating system by a visually impaired person.
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 handicapped 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 sufficiently good. For a physically handicapped 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. It 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 (normally
it's 80 by 25). There isn't any easy way to zoom in on sections of a
screen, but you can resize when needed.

3.1.2. X windows

There are a large number of ways of improving X windows. 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�
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 two known screen magnification programs, xmag which will
magnify a portion of the screen as much as needed but is very
primitive. The other one is xzoom. Previously I said that there had
to be something better than xmag, well this is it. See ``xzoom''.

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;

� crosshair cursors (horizontal and vertical lines from the very edge
of the screen)

� flashing cursors (flashes when you press a key)

There is no known software for this. I tried really hard to find
something; it must exist somewhere, it would be so easy to write I'm
sure

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.

3.1.3. Producing Large Print

Using large print with Linux is quite easy. There are several
techniques.

3.1.3.1. 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.

3.1.4. 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.

Can people please suggest other tools for generating large text. what
word processor would be good to suggest?

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. I still
haven't seen a version of this. 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 only one that I
know of that works is DECtalk from Digital, driven by 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.

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 program for Linux. It
needs training to recognise the particular font that it is going to
use and I have no idea how good it is. In principle, if it is good
enough, it should allow visually impaired people to read normal books
to some extent (accuracy of OCR is never high enough..).

More details would be nice. It seems to have to be trained which may
make it useless?

3.3. 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 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
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
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 think sticky mouse keys, which is due in a future release of X,
should make use of most programs possible.

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 causes calls for special
setup of the keyboard, which is, as far as I know, impossible at
present for Linux. This should become available very soon though
because the software needed to implement the main parts of this is
already written and in testing.

At that point, there should be a program which will display a keyboard
on the screen and accept input from some kind of pointer, including,
for example, eye movement.

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. 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 the 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.

5.3.2. Sticky Keys

Sticky keys are not available on Linux in any form as far as I know.
For the normal console they would need changes to the kernel code.
This wouldn't be very difficult, but would need someone who had basic
kernel programming skills to do it.

For X windows under Linux, the code already exists, but is not
available for normal users. Since `normal users' includes me, at
present, I cannot confirm that this will be usable.

5.3.3. Strange Input Hardware

There are a number of devices worth considering for input such as
touch screens and eye pointers. Most 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.

5.3.4. Controlling Physical Hardware From Linux

The main group of interest here are the Linux Lab Project. Generally,
much GPIB (a standard scientific equipment interface also known as the
IEEE bus) hardware can be controlled.

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.

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. 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 about two weeks out of date, so refer to
that please. I'll be using MOMspider to check for links disappearing.

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.

Emacspeak WWW page
<http://www.research.digital.com/CRL/personal/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/>

7.3. Suppliers

This is a UK supplier for the Braillex.

Alphavision Limited

7.4. Manufacturers

7.4.1. 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

7.4.1.1. Linux Supported Alphavision AT Products

� Braillex

7.4.2. 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
E-Mail <htmlurl url="mailto:info@blazie.com" name="info@blazie.com">
WWW <url url="http://www.blazie.com/">

7.4.2.1. Blazie AT Products

� Braille Lite (support discontinued)

7.4.3. 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 <url url="http://www.digital.com/">

7.4.3.1. Linux Supported DEC AT Products

� DECTalk Express

7.4.4. Kommunikations-Technik Stolper GmbH

KTS Stolper GmbH
Herzenhaldenweg 10
73095 Albershausen
Germany

Phone: +49 7161 37023
Fax: +49 7161 32632

7.4.4.1. 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

Emacs is the ultimate text editor. In fact it's far beyond a 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
advantage though, is that Emacspeak 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.

B.Begin3
Title: Emacspeak
Version: 3.52
Entered-date: 04JUL95

Description: Emacspeak an Emacs extension to provide
complete spoken feedback to a visually impaired user.
Requires a speech synthesizer.
I'm visually impaired
I currently use Emacspeak on my laptop.
Note-- You are not restricted to just Emacs --emacspeak
provides spoken access
to everything you can do from a terminal.
Keywords: Speech Access, Screen Reading,
Access for Visually Impaired Users.
Author: raman@crl.dec.com (T. V. Raman)
Maintained-by: raman@crl.dec.com (T. V. Raman)
Primary-site: ftp://crl.dec.com:/pub/digital/emacspeak
85K emacspeak-3.52.tar.gz
150K sounds.tar
Alternate-site: http://www.research.digital.com/CRL/personal/raman/emacspeak/emacspeak.html
Original-site: Implemented originally for Linux
Platforms: Dectalk Synthesizer, GNU Emacs 19, TCLX (Extended TCL)
Copying-policy: GPL
End

8.2. BRLTTY

This is a program for running a serial port Braille terminal.

22 March 1996: The authors hope to make the first official release,
version 1.0, sometime in the next few months. This version will
support Alva B.V.'s ABT3 series and Telesensory Systems Inc.'s
PowerBraille Navigator series displays, but support for Blazie
Engineering's Braille Lite will be discontinued, as it is not really
designed to be a Braille display and so does not have the necessary
features. In the meantime, if you have an Alva or TSI display and
want to use BRLTTY, contact the maintainer, Nikhil Nair
<nn201@cus.cam.ac.uk>.

Begin3
Title: BRLTTY - Access software for Unix for a blind person
using a soft Braille terminal
Version: 0.22, 22SEP95
Entered-date: 24SEP95
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@cam.ac.uk (Nikhil Nair)
jrbowden@bcs.org.uk (James Bowden)
Maintained-by: nn201@cam.ac.uk (Nikhil Nair)
Primary-site: sunsite.unc.edu /pub/Linux/utils/console
30kb brltty-0.22.tar.gz (includes the README file)
5kb brltty-0.22.README
Alternate-site:
Original-site:
Platforms: Linux (kernel 1.1.92 or later), not X/graphics.
Tieman B.V.'s CombiBraille (25/45/85 cell),
(with no support for the parallel interface or
in-built speech synthesizer;
Blazie Engineering's Braille Lite (not recommended).
Copying-policy: GPL
End

8.3. 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.

8.4. 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.

8.5. 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 xzoomare that it can't magnify under its
self, 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:<sect1>xzoom<label id="xzoom">

<P><tt/xzoom/ is a screen magnifier, in the same vein as <tt/xmag/,
but sufficiently better to be very useful to a visually impaired
person. The main disadvantages of <tt/xzoom/are that it can't magnify
under its self, that some of the key controls aren't compatible with
<tt/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. <tt/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).

<tscreen><verb>
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

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

8.6. 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.

8.6.1. 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 ----
} /* usleep */

#endif
+ #endif

void beep(count)
int count;

and run

patch < patch-file

then type

make

and the program should compile.

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 UKP (pounds sterling) or 11495 UKP for 2-D
Manufacturer: Alphavision Limited (UK)
Suppliers: ????

9.1.2. Brailloterm

``What is Brailloterm?

It's a refresh-able 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.

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 is one known (BRLTTY, see section ``BRLTTY'') and one rumoured
program for Linux (Braille enhanced screen.. no details yet).

9.2.1. CombiBraille

This is the recommended braille terminal to use with version 0.22BETA
of the BRLTTY software. It comes in three versions with 25, 45 or 85
braille cells.

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. and Telesensory Systems Inc. displays

These will be supported in the forthcoming version 1.0 of BRLTTY.

9.2.3. 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
Suppliers: ????

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)

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 packages 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.

10. Acknowledgements

Most 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.

T.V. Raman, the author of Emacspeak contributed comments, and
information and put 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.

A number of other people have contributed comments and information.
Specific contributions are acknowledged within the document.

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.