The BEAM XVI-SB Screen Reader Software
The BEAM XVI-SB screen reader application is responsible for providing
the user with a "view" of the computers display by use of a speech and/or
braille display unit. The screen reader builds up a model of the on screen
display and allows the user to interrogate this model to determine the
screens contents. A number of features are provided to ease usage of the
system. The screen reader has been designed so that the user views and
operates the application in a similar manner to sighted users. This aids
training on the system and allows sighted people to work with or assist
blind or visually impaired people easily.
The Screen Model
The XVISB screen reader generates and updates an internal model of the
screens contents. The model consists of a hierarchy of information on each
applications on screen windows. Information such as position, stacking
order and any text written into the window is kept.
In general the screen reader application is designed to follow the applications
normal operation. It will track the applications object that has the keyboard
focus automatically and in most cases the user operates the application
by means of the standard applications key presses. However, sometimes more
control is required. Some applications are designed to be operated with
a mouse and the keyboard interface is poor or non existent. Also the user
may wish to look around the displayed window for additional information
or functions that are not apparent when the application is driven by a
The XVISB screen reader provides the user with the means to navigate
through the information contained within the real time model by means of
special key presses and keys on the braille display. The system has the
concept of a current application window and a current object within the
application. The applications top level windows are considered as a sequential
list and the user can move the center of attention from one to the next
by means of simple key stokes. Each applications top level window is considered
to contain a number of objects laid out in a the dimensional plan. These
objects are things such as buttons, labels, lists text fields etc. The
user is able, by means of the numeric keypad and braille display keys,
to move around the windows objects and read their contents. The mouse cursor
is moved around over the objects of interest so that mouse buttons can
be pressed in the conventional way (the numeric keypad has three keys that
operate the mouse buttons).
All of the running applications top level windows are considered as a sequential
list and the user can move the screen readers center of attention from
one to the next by means of simple key stokes. This automatically de-iconifies
the window, if necessary, and moves the window to the front of all other
windows on the display.
Each applications top level window is considered to be a number of objects
laid out in lines from top to bottom. The screen reader provides the ability
to move left, right, up and down through these objects when in object mode.
The numeric keypad and the main braille display keys are used for this
purpose. Once on an object the objects contents and information on the
object is displayed on the braille display and spoken through the speech
unit. If the object contains many lines of text, the user can navigate
through the text in text mode.
When an object contains many lines of text, such as a multi-line address
field, the user can switch the system to text mode to navigate. Once in
text mode the user can navigate left, right, up and down through lines,
words and individual characters of the text. The numeric keypad and the
main braille display keys are used for this purpose. This is especially
useful when editing text or using applications that use a conventional
text only 80x24 display.
Whenever the screen readers center of attention is moved, either by user
navigation or tracking an applications focus change, the mouse cursor is
moved over the object of interest. This enables the user to press the mouse
buttons to operate the object if necessary. The mouse buttons can be driven
from the numeric keypad or the braille displays keys.
Information on various aspects of the screens display and individual object
are provided. The system will provide spoken information when important
aspects of the screens display changes such as a window popping up or disappearing.
The system will also provide information on the current application window
and the current object.
As well as speech output the braille used can move back an forward
through the list of information messages.
The speech interface has been designed to provide a simple system that
can provide the user with information on the on screen displayed data as
well as general information on the display and what is going on. The system
employs three voices. One is used to speck out the on screen data another
is used for information on the displayed objects or screen activity such
as windows popping up and the final one is used to speck out user key presses
to aid keyboard feedback. As well as speaking out the on screen data, the
system attempts to provide more information about the object whose data
is being accessed. Labels and object types can be associated with the objects
and, if available, this would be spoken out using the information voice.
For example, when over a text field containing a name the following could
be spoken: "Name text field, Terry". This aids screen navigation giving
the user automatic feedback on where they are.
The user can change the voice used, the speed of the speech and the
loudness. Numbers can be spoken as the individual digits or spoken as whole
numbers. The system attempts to understand telephone numbers, money and
The braille display interface has been designed to provide the user with
both on screen data and information as well as a convenient set of keys
for navigating the display. The braille display provides three status cells
and 40 or more data display cells. The first status cell gives status on
the operational mode of the system. The second cell provides information
on the current objects type and if it has keyboard focus. The third status
cell provides a line number which aids on screen navigation. As well as
displaying the on screen data within the data cells, the system attempts
to provide more information about the object whose data is being accessed.
A Label can be associated with each on screen object and, if available,
this would be displayed before the on screen data. For example, when over
a text field containing a name the following could be displayed: "Name
Terry". This aids screen navigation giving the user automatic feedback
on where they are. The text cursor is displayed by raising the lower two
pins of the appropriate status cell.
The braille front keys are used for screen navigation allowing the
user to move up, down, left and right both objects and text. The status
cell buttons provide additional features such as moving the on screen mouse
cursor over a particular character, moving between application windows,
pressing the mouse buttons and running simple macro commands.
In order to assist screen navigation, the user can set up locator keys
for each application window. Once set to a particular on screen object,
the user has only to press the appropriate locator hot key to move the
mouse cursor and screen readers center of attention to that object. This
cane speed up operation of commonly used windows enormously.
The system provides the ability to name graphical icons on the display.
If not named these icons will be given a unique numeric name.
The system provides a number of user options to tailor the system to users
particular needs. All of these can be accessed via hot keys. Options are
provided to control the speech display, the braille display and general
screen reader functions.
All of the system documentation is available on line and can be read with
the help viewer. In addition there is an interactive keyboard help mode
that provides assistance in learning what each key and key sequence on
the keyboard does.
Application Information System
To aid the users navigation and understanding of the on screen objects,
the system provides an application information system. This allows a file
to be created for each application listing the on screen objects and information
such as object types and labels as well a generic information. BEAM provide
a tool called the XVISB Appinfo application that enables system administrators
or trainers set up this information.
screen reader software is designed to work with both speech and braille
displays. Currently the only supported units are the Dolphin Apollo 2 speech
unit and the Alva Delphi 440 braille-speach unit.
Due to the huge variety of applications and GUI tool kits in use with the
X-Window system, not all applications are supported. Also some applications
are inherently graphical driven, such as CAD tools, and would not be able
to be used with this screen reader. Please contact BEAM with the applications
you wish to use.
Beam Access Points
||+44 (1454) 324512
||+44 (1454) 313172
Beam Ltd Northavon Business Center Dean Road Yate Bristol, BS17 5NH.