Software for the Visually Handicapped
Jaws
for Dos under Windows and Linux
JAWS
for DOS
JAWS for
DOS is a screen reader program which works under the DOS operating system.
This screen reader is meant to be used with an external speech synthesizer
connected to the computer through a serial communication line. This program
has been very popular during the days of DOS, and was in use till the Windows95
operating system slowly replaced DOS.
Henter and Joyce,
the firm that developed JAWS for DOS had moved towards a new product known
as JAWS for WINDOWS, which supports screen reading functions under Windows
95/98/2000/XP. JAWS for WINDOWS makes use of the sound hardware on a PC
and thus dispenses with the external synthesizer. With the growing popularity
of the Windows operating system, the firm had decided not to continue the
development of JAWS for DOS and had graciously made the software available
for free personal use.
JAWS for DOS is a
text mode application which works well under DOS. There are many applications
which are useful to the visually handicapped community which run in text
mode, e.g., Email, text based web browsers, text mode word processors and
data base applications. In the developing countries,
where the visually handicapped people are just getting to learn about computers,
JAWS for DOS can be a very useful program since it is freely available.
However, the need for an external speech synthesizer does restrict its
use even on a PC with sound hardware. There has been some interest in developing
text mode screen readers for use under Windows 95/98 since some of the
important text based internet applications could be used by the Visually
handicapped.
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Multilingual
Software developed at IIT Madras
The Indian Institute
of Technology, Madras, India, has been involved with a project of developing
multilingual applications and had been quite successful in developing an
application for data entry and editing of text in all Indian languages.
Systems Development Lab. (SDL), where this work had progressed for several
years, has enhanced the application to provide speech output in Indian
languages thus paving the way for the visually handicapped in India to
use computers in their own mother tongue. A number of organizations had
expressed an interest in SDL developing a screen reader for a PC that could
work like JAWS for DOS, since many training institutions in India continue
to offer DOS based training for the Visually handicapped. In deference
to their wishes, SDL has produced an application that uses JAWS for DOS
itself but allows it to operate with the sound hardware on a PC thus dispensing
with the external synthesizer. This is likely to benefit the visually handicapped
in India where external speech synthesizers are not easily available, though
PCs are.
SDL has accomplished
this by using a software speech synthesizer program developed at FPMS,
the technical university in Belgium . This program is called MBROLA and
its developers have made this freely available for personal use. IIT Madras
has provided the requisite interface program between JAWS for DOS and MBROLA
and thus has allowed screen reading functions to be utilized under the
DOS shell in the Windows as well as Linux environment.
The software synthesizer
approach has many advantages in practice. It allows for multilingual speech
output, either one language at a time or a mixture of languages. This way,
the screen reader would work well for people whose mother tongue is not
English but languages like French, German, Turkish etc.. Since DOS
(5.0 and above) had already supported different languages, the approach
to a multilingual screen reader is particularly elegant.
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Brief
description of the Software.
The IITM
software which works with JAWS for DOS has the following components.
1. An interface program which
allows JAWS for DOS to think that it is working with a standard external
speech synthesizer. This interface has been developed as a VXD (a virtual
device driver). This way, one can use JAWS for DOS as distributed without
having to effect any changes or modifications to the executable. The
external speech synthesizer simulated is the Double Talk synthesizer.
Under Windows2000/XP, one is not permitted to run vxds. So a virtual device
driver (vdd) based approach has been used. This results in a vdd file which
interfaces with Jaws for Dos. There are independent distributions for Win9x
and Win2000/XP. Under Linux, a different program is provided.
2. A text to speech conversion
program that produces phonemes conforming to the requirements of the
synthesizer so that MBROLA can produce multilingual speech output. This
program has been written assuming that JAWS for DOS has been configured
to work with a Double Talk speech synthesizer. A good part of this application
is also based on a free English text to phoneme utility known as Textalk.
The quality of the speech produced is extremely good since a dictionary
based method is used for generating the phonemes.
The above two are
applications which have to be invoked under DOS. This could be accomplished
by getting a DOS shell under Windows and running the required commands.
Under Linux, the DOS environment is provided through the Dosemu application.
It is assumed that
MBROLA is already installed on the computer. MBROLA may be downloaded from
the following web site in Belgium.
http://tcts.fpms.ac.be/synthesis/mbrola.html
Installing MBROLA
may require the help of a sighted friend. It is requested that visually
handicapped persons desiring to use the software distributed by IIT Madras,
take the help of a friend in installing both the IITM applications as well
as MBROLA.
For the benefit of
those not familiar with MBROLA, we have included a discussion on its concept
along with downloading and installation instructions. Please refer to the
relevant section on the right.
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The
software in operation.
The operation of the
IITM software with JAWS for DOS is similar to using JAWS with an external
Double Talk synthesizer. In the initial version, some of the controls applicable
to the Double talk synthesizer have been omitted. Also, the parameters
for the external speech Synthesizer may not work. The only parameter
that can be changed is the rate of speech output. This has to be effected
by specifying the speech rate in a text file which is read by the software
synthesizer program as it come up. This is a departure from the operation
of the software using an external Double Talk synthesizer.
By and large, the
system is well tuned for operation by most visually handicapped people,
who are not really experts at using the external synthesizer. The main
advantage is that regular DOS based applications such as Wordstar, Wordperfect,
Dbase etc., can be run. Though it is fairly easy to incorporate internet
applications such as email, web browsers (such as Lynx) , IIT Madras has
made available these as separate stand alone applications with sound enhancements
to the basic text mode applications. Please visit the relevant pages describing
Lynx and Pine as implemented with sound enhancements.
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Downloading
and installing the software.
The IITM application
that works with JAWS for DOS is distributed as a single zip file. Presently,
the version for MSWindows is available. The version for Linux will follow.
Download the file
jawsreader.zip
and extract the contents to the directory c:\jaws on your system. You will
have to create this directory first.
The c:\jaws directory
should also contain the JAWS for DOS downloaded from the Henter and Joyce
(now called Freedom Scientific), Web site and configured for use with Double
Talk and Wordperfect. IIT Madras is not sure if its own web site can distribute
the freely given JAWS for DOS. Should this be permitted we will also keep
at our web site a properly configured set of files of JAWS for DOS. Please
make sure you have correctly installed JAWS for DOS before attempting to
use the IITM software.
The JAWS for DOS program,
as downloaded from the Henter and Joyce site, contains very detailed instructions
for installing the software. If you are visually handicapped and live in
one of the developing countries, it is quite possible that you have little
experience with computers, let alone screen readers. Please take the help
of a sighted friend or a Volunteer organization to help you with the installation.
You may contact
Vidya Vrikshah, the
volunteer organization in Chennai for
help and guidance via email.
The files included in the
jawsreader.zip archive are
jawsreader.exe
param.txt
SHELLMSG.VXD
text710.dat
manual.txt
browse.com
The .exe file is an
executable (binary file) which should be invoked as follows from a DOS
shell under Windows 95/98. You may prepare a batch file to accomplish the
same. The browse.com file is a very small text browser which may be used
to read text files. We recommend the use of this program for reading any
text file under the screen reader.
As far as India, Pakistan,
Sri Lanka, Bangladesh and other South Asian countries are concerned, it
may be necessary for the visually handicapped person to get some training
in the use of JAWS for DOS. We are sure that there will be many friends
who would come forward to help them get familiar with the use of JAWS for
DOS.
First invoke the jawsreader
which is the virtual device driver program
c:> jawsreader
This would prepare
the system for use with JAWS by installing the VXD and the speech synthesis
program. This application will speak out the following text when it gets
invoked.
"Opening a new shell"
The next step is to invoke
JAWS
c:> jaws /com1
This would bring up
JAWS for DOS and the program will announce itself. The /com1 is a required
formality but does not in any way use the serial line. One could have a
modem or other device connected to the serial line and run it from other
windows applications or even DOS applications. Typically, a modem could
be connected to COM2 and a DOS application using the same could be run
with the screen reader.
At this point, JAWS
for DOS should be operational. Screen reading functions specified in Jaws
may be utilized by the person using the computer.
A short
video clip on this has been made available. Please use the Real Player
for viewing the clip.
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Running
the application under Win2000/XP
Under Windows 2000/XP,
a virtual device driver is required to be used. The distribution for WinXP/2000
has this file. Downloading and installing the application is almost identical
to the Win9x case except that a special batch file is invoked for starting
the jawsreader interface. The Readme.txt file included with the distribution
has relevant information.
Running
under Linux
Under Linux, one should
run the Dosemu application which provides the required DOS command shell.
The jawsreader program is invoked first from a Unix shell (different from
the one from which Dosemu will run). When invoked, jawsreader speaks out
the same message "opening a new shell". The Dosemu application is then
run to get the c:> prompt. At this point, the "jaws /com1" command is invoked
just as in the Windows9X case. The screen reader is ready for use. The
user will hear the messages from the Opening Screen of Jaws for Dos.
The application is
distributed as tarred gzipped archive. The Readme.txt file included in
the distribution has all the details relating to installation and use.
Formal distribution of this application has been deferred since there are
some minor bugs to fix. A link will appear below whn this job gets completed.
Useful
Applications
Here is a list applications
that Visually handicapped persons in the above mentioned countries could
learn to work with using JAWS for DOS and the IITM software speech synthesizer
application.
-
Text preparation and word processing
using Wordperfect or wordstar.
-
Reading already prepared text.
This will be useful for reading one's school lessons or college texts.
-
Running Data Base applications
that are text based under DOS.
-
Sending and receiving email.
-
Playing audio files.
-
To a limited extent play games
that work in Text Mode.
-
Prepare documents that could
be printed on a Braille embosser. The utility for this is known as nfbtrans
and nfbtrans runs as a text mode application under DOS.
Since JAWS for DOS
supports almost all DOS based text mode applications the above list is
far from complete. But for normal applications, where one would like to
use a computer to meet daily information requirements, the above should
certainly be adequate.
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