  BRLTTY Reference Manual
  Access to the Console Screen for Blind Persons using Refreshable
  Braille Displays
  Nikhil Nair <nn201@cus.cam.ac.uk>

  Nicolas Pitre <nico@fluxnic.net>

  Stéphane Doyon <s.doyon@videotron.ca>

  Dave Mielke <dave@mielke.cc>

  Version 6.7, October 2024

  Copyright © 1995-2024 by The BRLTTY Developers.  BRLTTY is free soft-
  ware, and comes with ABSOLUTELY NO WARRANTY.  It is placed under the
  terms of version 2 or later of The GNU General Public License as pub-
  lished by The Free Software Foundation.

  ______________________________________________________________________

  Table of Contents


  1. Formalities
     1.1 License
     1.2 Disclaimer
     1.3 Contact Information

  2. Introduction
     2.1 Feature Summary
     2.2 System Requirements

  3. The Build Procedure
     3.1 Installed File Hierarchy
     3.2 Installing from a TAR Ball
        3.2.1 Build Options
           3.2.1.1 System Defaults
           3.2.1.2 Directory Specification
           3.2.1.3 Build Features
           3.2.1.4 Miscellaneous Options
        3.2.2 Make File Targets
     3.3 Testing BRLTTY
     3.4 Starting BRLTTY
     3.5 Security Considerations
     3.6 Build and Run-Time Restrictions
     3.7 Installing from an RPM File
     3.8 Other Utilities
        3.8.1 brltty-config
        3.8.2 brltty-install
        3.8.3 brltest
        3.8.4 spktest
        3.8.5 scrtest
        3.8.6 ttbtest
        3.8.7 ctbtest
        3.8.8 tunetest

  4. Using BRLTTY
     4.1 Commands
        4.1.1 Vertical Motion
        4.1.2 Horizontal Motion
        4.1.3 Implicit Motion
        4.1.4 Feature Activation
        4.1.5 Mode Selection
        4.1.6 Preference Maintenance
        4.1.7 Menu Navigation
        4.1.8 Speech Controls
        4.1.9 Speech Navigation
        4.1.10 Virtual Terminal Switching
        4.1.11 Other Commands
        4.1.12 Character Commands
        4.1.13 Base Commands
     4.2 The Configuration File
     4.3 Command Line Options

  5. Feature Descriptions
     5.1 Cursor Routing
     5.2 Cut and Paste
     5.3 Pointer (Mouse) Support via GPM
     5.4 Alert Tunes
     5.5 Preferences Settings
        5.5.1 The Preferences Menu
           5.5.1.1 Navigating the Menu
           5.5.1.2 The Menu Items
     5.6 The Status Display
        5.6.1 Displays with 21 Cells or More
        5.6.2 Displays with 20 Cells or Less
     5.7 Command Learn Mode

  6. Tables
     6.1 Text Tables
        6.1.1 Text Table Format
        6.1.2 Text Table Directives
     6.2 Attributes Tables
        6.2.1 Attributes Table Format
        6.2.2 Attributes Table Directives
     6.3 Contraction Tables
        6.3.1 Contraction Table Format
        6.3.2 Contraction Table Operands
        6.3.3 Opcodes
           6.3.3.1 Table Administration
           6.3.3.2 Special Symbol Definition
           6.3.3.3 Character Translation
           6.3.3.4 Character Classes
     6.4 Key Tables
        6.4.1 Key Table Directives
           6.4.1.1 The Assign Directive
           6.4.1.2 The Bind Directive
           6.4.1.3 The Context Directive
           6.4.1.4 The Hide Directive
           6.4.1.5 The Hotkey Directive
           6.4.1.6 The IfKey Directive
           6.4.1.7 The Include Directive
           6.4.1.8 The Ignore Directive
           6.4.1.9 The Map Directive
           6.4.1.10 The Note Directive
           6.4.1.11 The Superimpose Directive
           6.4.1.12 The Title Directive
        6.4.2 Keyboard Properties

  7. Advanced Topics
     7.1 Installing Multiple Versions
     7.2 Installation/Rescue Root Disks for Linux
     7.3 Future Enhancements
     7.4 Known Bugs

  A. Supported Braille Displays
  B. Supported Speech Synthesizers
  C. Driver Identification Codes
  D. Supported Screen Drivers
  E. Operand Syntax
     E.1 Driver Specification
     E.2 Braille Device Specification
     E.3 PCM Device Specification
     E.4 MIDI Device Specification

  F. Standard Braille Dot Numbering Convention
  G. North American Braille Computer Code
  H. MIDI Instrument Table

  ______________________________________________________________________

  1.  Formalities

  1.1.  License

  This program is free software.  You may redistribute it and/or modify
  it under the terms of The GNU Lesser General Public License as
  published by The Free Software Foundation.  Version 2.1 (or any later
  version) of the license may be used.

  You should have received a copy of the license along with this
  program.  It should be in the file LICENSE-LGPL in the top-level
  directory.  If not, write to the Free Software Foundation Inc., 675
  Mass Ave, Cambridge, MA 02139, USA.

  1.2.  Disclaimer

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY - not even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  1.3.  Contact Information

  BRLTTY represents the work of a team.  For up-to-date information, see
  BRLTTY's web page at [http://brltty.app/].  As of this writing, the
  team includes:

  ·  Dave Mielke (maintainer, active)

     Web
        http://mielke.cc/

     E-Mail
        <dave@mielke.cc>

  ·  Samuel Thibault (active)

     Web
        http://dept-info.labri.fr/~thibault/

     E-Mail
        <samuel.thibault@ens-lyon.org>

  ·  Mario Lang (active)

     Web
        http://delysid.org/

     E-Mail
        <mlang@delysid.org>

  ·  Nicolas Pitre

     Web
        http://www.fluxnic.net/

     E-Mail
        <nico@fluxnic.net>

  ·  Stéphane Doyon

     Web
        http://pages.infinit.net/sdoyon/

     E-Mail
        <s.doyon@videotron.ca>

  ·  Nikhil Nair (author)

     E-Mail
        <nn201@cus.cam.ac.uk>

  Questions, comments, suggestions, criticisms, and contributions are
  all welcome.  Even though our e-mail addresses are listed above, the
  best way to contact us is via BRLTTY's mailing list.  You can post to
  the list by sending e-mail to <BRLTTY@brltty.app>.  If you aren't
  subscribed to the list then your posts will be held for moderator
  approval.  To subscribe, unsubscribe, change settings, view archives,
  etc, go to the list's information page at
  http://brltty.app/mailman/listinfo/brltty.

  2.  Introduction

  BRLTTY gives a braille user access to the text consoles of a
  Linux/Unix system.  It runs as a background process (daemon) which
  operates a refreshable braille display, and can be started very early
  in the system boot sequence.  It enables a braille user, therefore, to
  easily independently handle aspects of system administration such as
  single user mode entry, file system recovery, and boot problem
  analysis.  It even greatly eases such routine tasks as logging in.

  BRLTTY reproduces a rectangular portion of the screen (referred to
  within this document as `the window') as braille text on the display.
  Controls on the display can be used to move the window around on the
  screen, to enable and disable various viewing options, and to perform
  special functions.

  2.1.  Feature Summary

  BRLTTY provides the following capabilities:

  ·  Full implementation of the usual screen review facilities.

  ·  Choice between block, underline, or no cursor.

  ·  Optional underline to indicate specially highlighted text.

  ·  Optional use of blinking (rates individually settable) for cursor,
     special highlighting underline, and/or capital letters.

  ·  Screen freezing for leisurely review.

  ·  Intelligent cursor routing, allowing easy fetching of cursor within
     text editors, web browsers, etc., without moving ones hands from
     the braille display.

  ·  A cut-and-paste function (linear or rectangular) which is
     particularly useful for copying long file names, copying text
     between virtual terminals, entering complicated commands, etc.

  ·  Table driven in-line contracted braille (English and French
     provided).

  ·  Support for multiple braille codes.

  ·  Ability to identify an unknown character.

  ·  Ability to inspect character highlighting.

  ·  An on-line help facility for braille display commands.

  ·  A preferences menu.

  ·  Basic speech support.

  ·  Modular design allowing relatively easy addition of drivers for
     other braille displays and speech synthesizers.

  ·  An Application Programming Interface.

  2.2.  System Requirements

  To date, BRLTTY runs under Linux, Solaris, OpenBSD, FreeBSD, NetBSD,
  and Windows.  While ports to other Unix-like operating systems aren't
  currently planned, we do welcome any interest in such projects.


     Linux
        This software has been tested on a variety of Linux systems:

        ·  Desktops, laptops, and some PDAs.

        ·  Processors from a 386SX20 to a Pentium.

        ·  A huge range of memory sizes.

        ·  Several distributions including Debian, Red Hat, Slackware,
           and SuSE.

        ·  Many kernels, including 1.2.13, 2.0, 2.2, and 2.4.

     Solaris
        This software has been tested on the following Solaris systems:

        ·  The Sparc architecture (releases 7, 8, and 9).

        ·  The Intel architecture (release 9).

     OpenBSD
        This software has been tested on the following OpenBSD systems:

        ·  The Intel architecture (release 3.4).

     FreeBSD
        This software has been tested on the following FreeBSD systems:

        ·  The Intel architecture (release 5.1).

     NetBSD
        This software has been tested on the following NetBSD systems:

        ·  The Intel architecture (release 1.6).

     Windows
        This software has been tested on Windows 95, 98, and XP.

  On Linux, BRLTTY can inspect the content of the screen completely
  independently of any logged in user.  It does this by using a special
  device which provides easy access to the contents of the current
  virtual console.  This device was introduced in version 1.1.92 of the
  Linux kernel, and is normally called either /dev/vcsa or /dev/vcsa0
  (on systems with devfs it's called /dev/vcc/a).  For this reason,
  Linux kernel 1.1.92 or later is required if BRLTTY is to be used in
  this way.  This capability:

  ·  Allows BRLTTY to be started very early in the system boot sequence.

  ·  Enables the braille display to be fully operational during the
     login prompt.

  ·  Makes it much easier for a braille user to perform boot-time system
     administration tasks.

  A patch for the screen program is provided (see the Patches
  subdirectory).  It allows BRLTTY to access screen's screen image via
  shared memory, and, therefore, allows BRLTTY to be used quite
  effectively on platforms which don't have their own screen content
  inspection facility.  The main weakness of the screen approach is that
  BRLTTY can't be started until the user has logged in.

  BRLTTY only works with text-based consoles and applications.  It can
  be used with curses-based applications, but not with any application
  which either uses special VGA features or requires a graphics console
  (like the X Window system).

  You must also, of course, possess a supported refreshable braille
  display (see section ``Supported Braille Displays'' for the complete
  list).  We hope that additional displays will be supported in the
  future, so, if you have any vaguely technical programming information
  for a device which you'd like to see supported, then please let us
  know (see section ``Contact Information'').

  Finally, you need tools to build the executable from its source: make,
  C and C++ compilers, yacc, awk, etc.  The development tools provided
  with standard Unix distributions should suffice.  If you have
  problems, then contact us and we'll compile a binary for you.

  3.  The Build Procedure

  BRLTTY can be downloaded from its web site (see section ``Contact
  Information'' for its location).  All releases are provided as
  compressed ``tar balls''.  Newer releases are also provided as ``RPM''
  (RedHat Package Manager) files.

  That tidbit of information has probably peaked your curiosity, and now
  you just can't wait to get started.  It's a good idea, though, to
  first become familiar with the files which will ultimately be
  installed.

  3.1.  Installed File Hierarchy

  The build procedure should result in the installation of the following
  files:

     /bin/

        brltty
           The BRLTTY program.

        ``brltty-install''
           A utility for copying BRLTTY's ``installed file hierarchy''
           from one location to another.

        ``brltty-config''
           A utility which sets a number of environment variables to
           values which reflect the current installation of BRLTTY.

     /lib/

        libbrlapi.a
           Static archive of the Application Programming Interface.

        libbrlapi.so
           Dynamically loadable object for the Application Programming
           Interface.

     /lib/brltty/
        Your installation of BRLTTY may not have all of the following
        types of files.  They're only created as needed based on the
        build options you select (see ``Build Options'').

        brltty-brl.lst
           A list of the braille display drivers which have been built
           as dynamically loadable shared objects, and, therefore, which
           can be selected at run-time.  Each line consists of the two-
           letter identification code for a driver, a tab character, and
           a description of the braille display which that driver is
           for.

        libbrlttybdriver.so.1
           The dynamically loadable driver for a braille display, where
           driver is the two-letter ``driver identification code''.

        brltty-spk.lst
           A list of the speech synthesizer drivers which have been
           built as dynamically loadable shared objects, and, therefore,
           which can be selected at run-time.  Each line consists of the
           two-letter identification code for a driver, a tab character,
           and a description of the speech synthesizer which that driver
           is for.

        libbrlttysdriver.so.1
           The dynamically loadable driver for a speech synthesizer,
           where driver is the two-letter ``driver identification
           code''.

     /lib/brltty/rw/
        Files created at run-time, e.g. needed but missing system
        resources.

     /etc/

        brltty.conf
           System defaults for BRLTTY.

        brlapi.key
           The access key for BrlAPI.

     /etc/brltty/
        Your installation of BRLTTY may not have all of the following
        types of files.  They're only created as needed based on the
        build options you select (see ``Build Options'').

        *.conf
           Driver-specific configuration data.  Their names look more or
           less like brltty-driver.conf, where driver is the two-letter
           ``driver identification code''.

        *.atb
           Attributes tables (see section ``Attributes Tables'' for
           details).  Their names look like name.atb.

        *.ati
           Include files for attributes tables.

        *.ctb
           Contraction tables (see section ``Contraction Tables'' for
           details).  Their names look like language-country-level.ctb.

        *.cti
           Include files for contraction tables.

        *.ktb
           Key tables (see section ``Key Tables'' for details).  Their
           names look like name.ktb.

        *.kti
           Include files for key tables.

        *.ttb
           Text tables (see section ``Text Tables'' for details).  Their
           names look like language.ttb.

        *.tti
           Include files for text tables.

        *.hlp
           Driver-specific help pages.  Their names look more or less
           like brltty-driver.hlp, where driver is the two-letter
           ``driver identification code''.

     /var/lib/BrlAPI/
        Local sockets for connecting to the Application Programming
        Interface.

     /include/
        C header files for the Application Programming Interface.  Their
        names look like brlapi-function.h.  The main header is brlapi.h.

     /include/brltty/
        C header files for accessing braille hardware.  Their names look
        like brldefs-driver.h (where driver is the two-letter ``driver
        identification code'').  The headers brldefs.h and api.h are
        provided for backward compatibility and shouldn't be used.

     /man/
        Man pages.

        man1/name.1
           Man pages for BRLTTY-related user commands.

        man3/name.3
           Man pages for Application Programming Interface library
           routines.

  Some optional files which you should be aware of, although they aren't
  part of the installed file hierarchy, are:

     /etc/brltty.conf
        The system defaults configuration file.  It's created by the
        system administrator.  See ``The Configuration File'' for
        details.

     /etc/brltty-driver.prefs
        The saved preferences settings file (driver is a two-letter
        ``driver identification code'').  It's created by the
        ``PREFSAVE'' command.  See ``Preferences Settings'' for details.

  3.2.  Installing from a TAR Ball

  Here's what to do if you just want to install BRLTTY as quickly as
  possible, trusting that all of our defaults are correct.

  1. Download the source.  It'll be a file named brltty-release.tar.gz,
     e.g. brltty-3.0.tar.gz.

  2. Unpack the source into its native hierarchical structure.

       tar xzf brltty-release.tar.gz


  This should create the directory brltty-release.

  3. Change to the source directory, configure, compile, and install
     BRLTTY.

       cd brltty-release
       ./configure
       make install


  This should be done as root.

  To uninstall BRLTTY, do:

       cd brltty-release
       make uninstall


  That's all there's to it.  Now, for those who really want to know
  what's going on, here are the details.

  3.2.1.  Build Options

  The first step in building BRLTTY is to configure it for your system
  and/or for your personal needs.  This is done by running the configure
  script in BRLTTY's top-level directory.  We've tried to make the
  defaults fit the most common case, so, assuming that you're not
  attempting to do anything out of the ordinary, you may not need to do
  anything more complicated than invoke this script without specifying
  any options at all.

       ./configure


  If, however, you have some special requirements, or even if you're
  just adventurous, you should find out what your choices are.

       ./configure --help


  You should also check out the README file in the subdirectory contain-
  ing the driver for your braille display for any additional display-
  specific instructions.

  3.2.1.1.  System Defaults


     --with-braille-driver=driver
        Specify the braille display drivers which are to be linked into
        the BRLTTY binary.  Those drivers which aren't listed via this
        option are built as dynamically loadable shared objects and can
        still be selected at run-time.  Each driver must be identified
        either by its two-letter ``driver identification code'' or by
        its proper name (full or abbreviated).  The driver identifiers
        must be separated from one another by a single comma.  If a
        driver identifier is prefixed by a minus sign (-), then that
        driver is excluded from the build.  Any of the following words
        can also be used as the operand of this option:

        all
           Link all of the drivers into the binary.  Don't build any of
           them as dynamically loadable shared objects.  This word may
           also be specified as the final element of a driver list.
           This is how to specify the default driver when all the
           drivers are to be linked in.

        -all
           Only build those drivers which have been explicitly included
           via this option.

        no Don't build any drivers at all.  This is equivalent to
           specifying --without-braille-driver.

        yes
           Build all of the drivers as dynamically loadable shared
           objects.  Don't link any of them into the binary.  This is
           equivalent to specifying --with-braille-driver.

        See the ``braille-driver'' configuration file directive and the
        ``-b'' command line option for run-time selection.

     --with-braille-parameters=[driver:]name=value,...
        Specify the default parameter settings for the braille display
        drivers.  If the same parameter is specified more than once,
        then its rightmost assignment is used.  If a parameter name is
        qualified by a driver (see section ``Driver Identification
        Codes'') then that setting only applies to that driver; if it
        isn't then it applies to all drivers.  For a description of the
        parameters accepted by a specific driver, please see the
        documentation for that driver.  See the ``braille-parameters''
        configuration file directive and the ``-B'' command line option
        for run-time selection.

     --with-braille-device=device,...
        Specify the default device to which the braille display is
        connected (see section ``Braille Device Specification'').  If
        this option isn't specified then usb: is assumed if USB support
        is available, bluetooth: is assumed if Bluetooth support is
        available, and usb:,bluetooth: is assumed if both are available.
        If neither USB nor Bluetooth support is available then an
        operating system appropriate path for the primary (first) serial
        port (device) is assumed.  See the ``braille-device''
        configuration file directive and the ``-d'' command line option
        for run-time selection.

     --with-libbraille=directory
        Specify the installed location of the Libbraille package, and
        build the Libbraille braille display driver (see ``Build
        Restrictions'').  Any of the following words can also be used as
        the operand of this option:

        no Don't build the driver.  This is equivalent to specifying
           --without-libbraille.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/Libbraille, /usr/local/libbraille,
           /opt/Libbraille, or /opt/libbraille.  This is equivalent to
           specifying --with-libbraille.

     --with-text-table=file
        Specify the built-in (fallback) text table (see section ``Text
        Tables'' for details).  The specified table is linked into the
        BRLTTY binary, and is used either if locale-based autoselection
        fails or if the requested table can't be loaded.  The absolute
        path to a table outside the source tree may be specified.  The
        .ttb extension is optional.  If this option isn't specified,
        then en-nabcc, a commonly (in North America) used 8-dot variant
        of the ``North American Braille Computer Code'', is assumed.
        See the ``text-table'' configuration file directive and the
        ``-t'' command line option for run-time selection.  This setting
        can be changed with the ``Text Table'' preference.

     --with-attributes-table=file
        Specify the built-in (fallback) attributes table (see section
        ``Attributes Translation'' for details).  The specified table is
        linked into the BRLTTY binary, and is used if the requested
        table can't be loaded.  The absolute path to a table outside the
        source tree may be specified.  The .atb extension is optional.
        If this option isn't specified, then left_right is assumed.
        Change it to invleft_right if you'd like it done the old way.
        See the ``attributes-table'' configuration file directive and
        the ``-a'' command line option for run-time selection.  This
        setting can be changed with the ``Attributes Table'' preference.

     --with-speech-driver=driver
        Specify the speech synthesizer drivers which are to be linked
        into the BRLTTY binary.  Those drivers which aren't listed via
        this option are built as dynamically loadable shared objects and
        can still be selected at run-time.  Each driver must be
        identified either by its two-letter ``driver identification
        code'' or by its proper name (full or abbreviated).  The driver
        identifiers must be separated from one another by a single
        comma.  If a driver identifier is prefixed by a minus sign (-),
        then that driver is excluded from the build.  Any of the
        following words can also be used as the operand of this option:

        all
           Link all of the drivers into the binary.  Don't build any of
           them as dynamically loadable shared objects.  This word may
           also be specified as the final element of a driver list.
           This is how to specify the default driver when all the
           drivers are to be linked in.

        -all
           Only build those drivers which have been explicitly included
           via this option.

        no Don't build any drivers at all.  This is equivalent to
           specifying --without-speech-driver.

        yes
           Build all of the drivers as dynamically loadable shared
           objects.  Don't link any of them into the binary.  This is
           equivalent to specifying --with-speech-driver.

        See the ``speech-driver'' configuration file directive and the
        ``-s'' command line option for run-time selection.

     --with-speech-parameters=[driver:]name=value,...
        Specify the default parameter settings for the speech
        synthesizer drivers.  If the same parameter is specified more
        than once, then its rightmost assignment is used.  If a
        parameter name is qualified by a driver (see section ``Driver
        Identification Codes'') then that setting only applies to that
        driver; if it isn't then it applies to all drivers.  For a
        description of the parameters accepted by a specific driver,
        please see the documentation for that driver.  See the ``speech-
        parameters'' configuration file directive and the ``-S'' command
        line option for run-time selection.

     --with-flite=directory
        Specify the installed location of the FestivalLite text-to-
        speech package, and build the FestivalLite speech synthesizer
        driver (see ``Build Restrictions'').  Any of the following words
        can also be used as the operand of this option:

        no Don't build the driver.  This is equivalent to specifying
           --without-flite.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/FestivalLite, /usr/local/flite,
           /opt/FestivalLite, or /opt/flite.  This is equivalent to
           specifying --with-flite.

     --with-flite-language=language
        Specify the language which the FestivalLite text to speech
        engine is to use.  The default language is usenglish.

     --with-flite-lexicon=lexicon
        Specify the lexicon which the FestivalLite text to speech engine
        is to use.  The default lexicon is cmulex.

     --with-flite-voice=voice
        Specify the voice which the FestivalLite text to speech engine
        is to use.  The default voice is cmu_us_kal16.

     --with-mikropuhe=directory
        Specify the installed location of the Mikropuhe text-to-speech
        package, and build the Mikropuhe speech synthesizer driver (see
        ``Build Restrictions'').  Any of the following words can also be
        used as the operand of this option:

        no Don't build the driver.  This is equivalent to specifying
           --without-mikropuhe.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/Mikropuhe, /usr/local/mikropuhe,
           /opt/Mikropuhe, or /opt/mikropuhe.  This is equivalent to
           specifying --with-mikropuhe.

     --with-speechd=directory
        Specify the installed location of the speech-dispatcher text-to-
        speech package, and build the speech-dispatcher speech
        synthesizer driver.  Any of the following words can also be used
        as the operand of this option:

        no Don't build the driver.  This is equivalent to specifying
           --without-speechd.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/speech-dispatcher, /usr/local/speechd,
           /opt/speech-dispatcher, or /opt/speechd.  This is equivalent
           to specifying --with-speechd.

     --with-swift=directory
        Specify the installed location of the Swift text-to-speech
        package, and build the Swift speech synthesizer driver.  Any of
        the following words can also be used as the operand of this
        option:

        no Don't build the driver.  This is equivalent to specifying
           --without-swift.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/Swift, /usr/local/swift, /opt/Swift,
           or /opt/swift.  This is equivalent to specifying --with-
           swift.

     --with-theta=directory
        Specify the installed location of the Theta text-to-speech
        package, and build the Theta speech synthesizer driver (see
        ``Build Restrictions'').  Any of the following words can also be
        used as the operand of this option:

        no Don't build the driver.  This is equivalent to specifying
           --without-theta.

        yes
           Build the driver if the package can be found in /usr,
           /usr/local, /usr/local/Theta, /usr/local/theta, /opt/Theta,
           or /opt/theta.  This is equivalent to specifying --with-
           theta.

     --with-screen-driver=driver
        Specify the screen drivers which are to be linked into the
        BRLTTY binary.  Those drivers which aren't listed via this
        option are built as dynamically loadable shared objects and can
        still be selected at run-time.  Each driver must be identified
        either by its two-letter driver identification code (see section
        ``Supported Screen Drivers'') or by its proper name (full or
        abbreviated).  The driver identifiers must be separated from one
        another by a single comma.  If a driver identifier is prefixed
        by a minus sign (-), then that driver is excluded from the
        build.  Any of the following words can also be used as the
        operand of this option:

        all
           Link all of the drivers into the binary.  Don't build any of
           them as dynamically loadable shared objects.  This word may
           also be specified as the final element of a driver list.
           This is how to specify the default driver when all the
           drivers are to be linked in.

        -all
           Only build those drivers which have been explicitly included
           via this option.

        no Don't build any drivers at all.  This is equivalent to
           specifying --without-screen-driver.

        yes
           Build all of the drivers as dynamically loadable shared
           objects.  Don't link any of them into the binary.  This is
           equivalent to specifying --with-screen-driver.

        The first non-excluded driver becomes the default driver.  If
        this option isn't specified, or if no driver is specifically in-
        cluded, then an operating system appropriate default is se-
        lected.  If a native driver for the current operating system is
        available, then that driver is selected; if not, then sc is se-
        lected.  See the ``screen-driver'' configuration file directive
        and the ``-x'' command line option for run-time selection.

     --with-screen-parameters=[driver:]name=value,...
        Specify the default parameter settings for the screen drivers.
        If the same parameter is specified more than once, then its
        rightmost assignment is used.  If a parameter name is qualified
        by a driver (see section ``Supported Screen Drivers'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``screen-parameters'' configuration file directive and
        the ``-X'' command line option for run-time selection.

     --with-usb-package=package,...
        Specify the package which is to be used for USB I/O.  The
        package names must be separated from one another by a single
        comma, and are processed from left to right.  The first one
        which is installed on the system is selected.  The following
        packages are supported:

        1. libusb

        2. libusb-1.0

        Any of the following words can also be used as the operand of
        this option:

        no Don't support USB I/O.  This is equivalent to specifying
           --without-usb-package.

        yes
           Use native support for USB I/O.  If native support isn't
           available for the current platform then use the first
           available supported package (as per the order specified
           above).  This is equivalent to specifying --with-usb-package.

     --with-bluetooth-package=package,...
        Specify the package which is to be used for Bluetooth I/O.  The
        package names must be separated from one another by a single
        comma, and are processed from left to right.  The first one
        which is installed on the system is selected.  The following
        packages are supported:

        1. (no packages are currently supported)

        Any of the following words can also be used as the operand of
        this option:

        no Don't support Bluetooth I/O.  This is equivalent to
           specifying --without-bluetooth-package.

        yes
           Use native support for Bluetooth I/O.  If native support
           isn't available for the current platform then use the first
           available supported package (as per the order specified
           above).  This is equivalent to specifying --with-bluetooth-
           package.

  3.2.1.2.  Directory Specification


     --with-execute-root=directory
        Specify the directory at which the ``installed file hierarchy''
        is to be rooted at run-time.  The absolute path should be
        supplied.  If this option isn't specified, then the system's
        root directory is assumed.  Use this option if you need to
        install BRLTTY's run-time files in a non-standard location.  You
        need to use this feature, for example, if you'd like to have
        more than one version of BRLTTY installed at the same time (see
        section ``Installing Multiple Versions'' for an example of how
        to do this).

     --with-install-root=directory
        Specify the directory beneath which the ``installed file
        hierarchy'' is to be installed.  The absolute path should be
        supplied.  If this option isn't specified, then the run-time
        package root (see the ``--with-execute-root'' build option) is
        assumed.  This directory is only used by ``make install'' and
        ``make uninstall''.  Use this option if you need to install
        BRLTTY in a different location than the one from which it'll
        ultimately be executed.  You need to use this feature, for
        example, if you're building BRLTTY on one system for use on
        another.

     --prefix=directory
        Specify the directory within the ``installed file hierarchy''
        where the default directories for the architecture-independent
        files are to be rooted.  These directories include:

        ·  the ``writable directory''

        ·  the ``data directory''

        ·  the ``configuration directory''

        ·  the ``manpage directory''

        ·  the ``include directory''

        The absolute path should be supplied.  If this option isn't
        specified, then the system's root directory is assumed.  This
        directory is rooted at the directory specified by the ``--with-
        execute-root'' build option.

     --exec-prefix=directory
        Specify the directory within the ``installed file hierarchy''
        where the default directories for the architecture-dependent
        files are to be rooted.  These directories include:

        ·  the ``program directory''

        ·  the ``library directory''

        ·  the ``API directory''

        The absolute path should be supplied.  If this option isn't
        specified, then the directory specified via the ``--prefix''
        build option is assumed.  This directory is rooted at the direc-
        tory specified by the ``--with-execute-root'' build option.

     --libdir=directory
        Specify the directory within the ``installed file hierarchy''
        where the static archive and the dynamically loadable object for
        the Application Programming Interface are to be installed.  The
        absolute path should be supplied.  If this option isn't
        specified, then the directory specified via the standard
        configure option --libdir (which defaults to /lib rooted at the
        directory specified by the ``--exec-prefix'' build option) is
        assumed.  The directory is created if it doesn't exist.

     --sysconfdir=directory
        Specify the directory within the ``installed file hierarchy''
        where the configuration files are to be installed.  The absolute
        path should be supplied.  If this option isn't specified, then
        the directory specified via the standard configure option
        --sysconfdir (which defaults to /etc rooted at the directory
        specified by the ``--prefix'' build option) is assumed.  The
        directory is created if it doesn't exist.

     --with-program-directory=directory
        Specify the directory within the ``installed file hierarchy''
        where the runnable programs (binaries, executables) are to be
        installed.  The absolute path should be supplied.  If this
        option isn't specified, then the directory specified via the
        standard configure option --bindir (which defaults to /bin
        rooted at the directory specified by the ``--exec-prefix'' build
        option) is assumed.  The directory is created if it doesn't
        exist.

     --with-library-directory=directory
        Specify the directory within the ``installed file hierarchy''
        where the drivers and other architecture-dependent files are to
        be installed.  The absolute path should be supplied.  If this
        option isn't specified, then the brltty subdirectory of the
        directory specified via the standard configure option --libdir
        (which defaults to /lib rooted at the directory specified by the
        ``--exec-prefix'' build option) is assumed.  The directory is
        created if it doesn't exist.

     --with-writable-directory=directory
        Specify the directory within the ``installed file hierarchy''
        which may be written to.  The absolute path should be supplied.
        Any of the following words can also be used as the operand of
        this option:

        no Don't define a writable directory.  This is equivalent to
           specifying --without-writable-directory.

        yes
           Use the default location.  This is equivalent to specifying
           --with-writable-directory.

        If this option isn't specified, then the rw subdirectory of the
        directory specified via the ``--with-library-directory'' build
        option is assumed.  The directory is created if it doesn't ex-
        ist.

     --with-data-directory=directory
        Specify the directory within the ``installed file hierarchy''
        where the tables, help pages, and other architecture-independent
        files are to be installed.  The absolute path should be
        supplied.  If this option isn't specified, then the brltty
        subdirectory of the directory specified via the standard
        configure option --sysconfdir (which defaults to /etc rooted at
        the directory specified by the ``--prefix'' build option) is
        assumed.  The directory is created if it doesn't exist.

     --with-manpage-directory=directory
        Specify the directory within the ``installed file hierarchy''
        where the man pages are to be installed.  The absolute path
        should be supplied.  If this option isn't specified, then the
        directory specified via the standard configure option --mandir
        (which defaults to /man rooted at the directory specified by the
        ``--prefix'' build option) is assumed.  The directory is created
        if it doesn't exist.

     --with-include-directory=directory
        Specify the directory within the ``installed file hierarchy''
        where the C header files for the Application Programming
        Interface are to be installed.  The absolute path should be
        supplied.  If this option isn't specified, then the brltty
        subdirectory of the directory specified via the standard
        configure option --includedir (which defaults to /include rooted
        at the directory specified by the ``--prefix'' build option) is
        assumed.  The directory is created if it doesn't exist.

  3.2.1.3.  Build Features

  These options are primarily useful when building BRLTTY for use on a
  boot disk.

     --enable-standalone-programs
        Create statically linked, rather than dynamically linked,
        programs.  This option removes all dependencies on shared
        objects at run-time.  Only the default drivers (see the
        ``--with-braille-driver'', ``--with-speech-driver'', and
        ``--with-screen-driver'' build options) are compiled.

     --enable-relocatable-install
        If this feature is enabled then all internal paths are
        recalculated to be relative to the program directory.  If it's
        disabled then all internal paths are absolute.  This feature
        allows the entire installed file hierarchy to be copied or
        moved, in tact, from one place to another, and is primarily
        intended for use on Windows platforms.

     --disable-stripping
        Don't remove the symbol tables from executables and shared
        objects when installing them.

     --disable-learn-mode
        Reduce program size by excluding command learn mode (see section
        ``Command Learn Mode'').

     --disable-contracted-braille
        Reduce program size by excluding support for contracted braille
        (see section ``Contraction Tables'').

     --disable-speech-support
        Reduce program size by excluding support for speech
        synthesizers.

     --disable-iconv
        Reduce program size by excluding support for character set
        conversion.

     --disable-icu
        Reduce program size by excluding support for Unicode-based
        internationalization.

     --disable-x
        Reduce program size by excluding support for X11.

     --disable-beeper-support
        Reduce program size by excluding support for the console tone
        generator.

     --disable-pcm-support
        Reduce program size by excluding support for the digital audio
        interface on the sound card.

     --enable-pcm-support=interface
        If a platform provides more than one digital audio interface
        then the one which is to be used may be specified.

         Platform   Interface   Description
         _______________________________________________________________
         Linux      oss         Open Sound System
                    alsa        Advanced Linux Sound Architecture


     --disable-midi-support
        Reduce program size by excluding support for the Musical
        Instrument Digital Interface of the sound card.

     --enable-midi-support=interface
        If a platform provides more than one Musical Instrument Digital
        Interface then the one which is to be used may be specified.

         Platform   Interface   Description
         _______________________________________________________________
         Linux      oss         Open Sound System
                    alsa        Advanced Linux Sound Architecture


     --disable-fm-support
        Reduce program size by excluding support for the FM synthesizer
        on an AdLib, OPL3, Sound Blaster, or equivalent sound card.

     --disable-pm-configfile
        Reduce program size by excluding support for the Papenmeier
        driver's configuration file.

     --disable-gpm
        Reduce program size by excluding the interface to the gpm
        application which allows BRLTTY to interact with the pointer
        (mouse) device (see section ``Pointer (Mouse) Support via
        GPM'').

     --disable-api
        Reduce program size by excluding the Application Programming
        Interface.

     --with-api-parameters=name=value,...
        Specify the default parameter settings for the Application
        Programming Interface.  If the same parameter is specified more
        than once, then its rightmost assignment is used.  For a
        description of the parameters accepted by the interface, please
        see the BrlAPI reference manual.  See the ``api-parameters''
        configuration file directive and the ``-A'' command line option
        for run-time selection.

     --disable-caml-bindings
        Don't build the Caml bindings for the Application Programming
        Interface.

     --disable-java-bindings
        Don't build the Java bindings for the Application Programming
        Interface.

     --disable-lisp-bindings
        Don't build the Lisp bindings for the Application Programming
        Interface.

     --disable-python-bindings
        Don't build the Python bindings for the Application Programming
        Interface.

     --disable-tcl-bindings
        Don't build the Tcl bindings for the Application Programming
        Interface.

     --with-tcl-config=path
        Specify the location of the Tcl configuration script
        (tclConfig.sh).  Either the path to the script itself or to the
        directory containing it may be supplied.  Any of the following
        words can also be used as the operand of this option:

        no Use other means to guess if Tcl is available, and, if so,
           where it has been installed.  This is equivalent to
           specifying --without-tcl-config.

        yes
           Search for the script in a few commonly used directories.
           This is equivalent to specifying --with-tcl-config.

  3.2.1.4.  Miscellaneous Options


     --with-init-path=path
        Specify the path to the real init program for the system.  The
        absolute path should be supplied.  If this option is specified,
        then:

        1. The init program should be moved to a new location.

        2. brltty should be moved to the init program's original
           location.

        3. When the system runs init at startup, brltty is actually run.
           It puts itself into the background, and runs the real init in
           the foreground.  This is one (somewhat sneaky) way to have
           braille right at the outset.  It's especially useful for some
           install/rescue disks.

        If this option isn't specified, then this feature isn't acti-
        vated.  This option is primarily intended for building a brail-
        lified installer image.

     --with-stderr-path=path
        Specify the path to the file or device where standard error
        output is to be written.  The absolute path should be supplied.
        If this option isn't specified, then this feature isn't
        activated.  This option is primarily intended for building a
        braillified installer image.

  3.2.2.  Make File Targets

  Once BRLTTY has been configured, the next steps are to compile and to
  install it.  These are done by applying the system's make command to
  BRLTTY's main make file (Makefile in the top-level directory).
  BRLTTY's make file supports most of the common application maintenance
  targets.  They include:

     make
        A shortcut for make all.

     make all
        Compile and link the BRLTTY executable, its drivers and their
        help pages, its test programs, and a few other small utilities.

     make install
        Complete the compile and link phase (see ``make all''), and then
        install the BRLTTY executable, its data files, drivers, and help
        pages, in the correct places and with the correct permissions.

     make uninstall
        Remove the BRLTTY executable, its data files, drivers, and help
        pages, from the system.

     make clean
        Ensure that the next compile and link (see ``make all'') will be
        done from scratch by removing the results of compiling, linking,
        and testing from the source directory structure.  This includes
        the removal of object files, executables, dynamically loadable
        shared objects, driver lists, help pages, temporary header
        files, and core files.

     make distclean
        In addition to removing the results of compiling and linking
        (see ``make clean''):

        ·  Remove the results of BRLTTY configuration (see ``Build
           Options'').  This includes the removal of config.mk,
           config.h, config.cache, config.status, and config.log.

        ·  Remove other files from the source directory structure which
           tend to accumulate over time but which don't belong there.
           This includes the removal of editor backup files, test case
           results, rejected patch hunks, and copies of original source
           files.

  3.3.  Testing BRLTTY

  After compiling, linking, and installing BRLTTY, it's a good idea to
  give it a quick test before activating it permanently.  To do so,
  invoke it with the command:

       brltty -bdriver -ddevice


  For driver, specify the two-letter ``driver identification code'' cor-
  responding to your braille display.  For device, specify the full path
  for the device to which your braille display is connected.

  If you don't want to explicitly identify the driver and device each
  time you start BRLTTY, then you can take two approaches.  You can
  establish system defaults via the ``braille-driver'' and the
  ``braille-device'' configuration file directives, and/or compile your
  needs right into BRLTTY via the ``--with-braille-driver'' and the
  ``--with-braille-device'' build options.

  If all is well, BRLTTY's version identification message should appear
  on the braille display for a few seconds (see the ``-M'' command line
  option).  After it goes away (which you can hasten by pressing any key
  on the display), the area of the screen where the cursor is should
  appear.  This means that you should expect to see your shell's command
  prompt.  Then, as you enter your next command, each character should
  appear on the display as it's typed on the keyboard.

  If this is your experience, then leave BRLTTY running, and enjoy it.
  If this isn't your experience, then it may be necessary to test each
  driver separately in order to isolate the source of the problem.  The
  screen driver can be tested with ``scrtest'', and the braille display
  driver can be tested with ``brltest''.

  If you experience a problem which requires a lot of digging, then you
  may wish to use the following brltty command line options:

  ·  ``-ldebug'' to log lots of diagnostic messages.

  ·  ``-n'' to keep BRLTTY in the foreground.

  ·  ``-e'' to direct diagnostic messages to standard error rather than
     to the system log.

  3.4.  Starting BRLTTY

  BRLTTY, when properly installed, is invoked with the single command
  brltty.  A configuration file (see section ``The Configuration File''
  for details) can be created in order to establish system defaults for
  such things as the location of the preferences file, the braille
  display driver to be used, the device to which the braille display is
  connected, and the text table to be used.  Many options (see section
  ``Command Line Options'' for details) allow explicit run-time
  specification of such things as the location of the configuration
  file, any defaults established within the configuration file, and some
  characteristics which have reasonable defaults but which those who
  think they know what they're doing may wish to play with.  The ``-h''
  option displays a summary of all the options.  The ``-V'' option
  displays the current version of the program, the API, and the selected
  drivers.  The ``-v'' option displays the values of the options after
  all sources have been considered.

  It's probably best to have the system automatically start BRLTTY as
  part of the boot sequence so that the braille display is already up
  and running when the login prompt appears.  Most (probably all)
  distributions provide a script wherein user-supplied applications can
  be safely started near the end of the boot sequence.  The name of this
  script is distribution-dependent.  Here are the ones we know about so
  far:

     Red Hat
        /etc/rc.d/rc.local

  Starting BRLTTY from this script is a good approach (especially for
  new users).  Just add a set of lines like these:


       if [ -x /bin/brltty -a -f /etc/brltty.conf ]
       then
          /bin/brltty
       fi

  This can usually be abbreviated to the somewhat less readable form:


       [ -x /bin/brltty -a -f /etc/brltty.conf ] && /bin/brltty

  Don't add these lines before the first line (which usually looks like
  #!/bin/sh).

  If the braille display is to be used by a system administrator, then
  it should probably be started as early as possible during the boot
  sequence (like before the file systems are checked) so that the
  display is usable in the event that something goes wrong during these
  checks and the system drops into single user mode.  Again, exactly
  where it's best to do this is distribution-dependent.  Here are the
  places we know about so far:

     Debian
        /etc/init.d/boot (for older releases)
        /etc/init.d/ (for newer releases)
        A brltty package is provided (see
        [http://packages.debian.org/brltty]) as of release 3.0 (Woody).
        Since this package takes care of starting BRLTTY, there's no
        need for user-supplied code to do so if it's installed.  If you
        need the daemon to run with some command-line options, you can
        change the contents between quotes on the directive ARGUMENTS in
        the /etc/default/brltty file.

     RedHat
        /etc/rc.d/rc.sysinit
        Beware that later releases, in order to support a more user-
        oriented system initialization procedure, have this script
        reinvoke itself such that it's under the control of initlog.
        Look, probably right up near the top, for a set of lines like
        these:


              # Rerun ourselves through initlog
              if [ -z "$IN_INITLOG" ]; then
                [ -f /sbin/initlog ] && exec /sbin/initlog $INITLOG_ARGS -r /etc/rc.sysinit
              fi


     Starting BRLTTY before this reinvocation results in two BRLTTY
     processes running at the same time, and that'll give you no end of
     problems.  If your version of this script has this feature, then
     make sure you start BRLTTY after the lines which implement it.

     Slackware
        /etc/rc.d/rc.S

     SuSE
        /sbin/init.d/boot

  An alternative is to start BRLTTY from /etc/inittab.  You have two
  choices if you choose this route.

  ·  If you want it to be started really early but don't need it to be
     automatically restarted if it dies, then add a line like this
     before the first :sysinit: line which is already in there.

       brl::sysinit:/bin/brltty


  ·  If you don't mind it being started later but do want it to be
     automatically restarted if it dies, then add a line like this
     anywhere within the file.

       brl:12345:respawn:/bin/brltty -n


  The ``-n'' (--nodaemon) option is very important when running BRLTTY
  with init's respawn facility.  You'll end up with hundreds of BRLTTY
  processes all running at the same time if you forget to specify it.

  Check that the identifier (brl in these examples) isn't already being
  used by another entry, and, if it is, choose a different one which
  isn't.

  Note that a command like kill -TERM is sufficient to stop BRLTTY in
  its tracks.  If it dies during entry into single user mode, for
  example, it may well be due to a problem of this nature.

  Some systems, as part of the boot sequence, probe the serial ports
  (usually in order to automatically find the mouse and deduce its
  type).  If your braille display is using a serial port, this kind of
  probing may be enough to get it confused.  If this happens to you,
  then try restarting the braille driver (see the ``RESTARTBRL''
  command).  Better yet, turn off the serial port probing.  Here's what
  we know so far about how to do this:

     Red Hat
        The probing is done by a service named kudzu.  Use the command

          chkconfig --list kudzu

     to see if it's been enabled.  Use the command

          chkconfig kudzu off

     to disable it.  Later releases allow you to let kudzu run without
     probing the serial ports.  To do this, edit the file /etc/syscon-
     fig/kudzu, and set SAFE to yes.

  If you want to start BRLTTY before any file systems are mounted, then
  ensure that all of its components are installed within the root file
  system.  See the ``--with-execute-root'', ``--bindir'', ``--libdir'',
  ``--with-writable-directory'', and ``--with-data-directory'' build
  options.

  3.5.  Security Considerations

  BRLTTY needs to run with root privileges because it needs read and
  write access for the port to which the braille display is connected,
  read access to /dev/vcsa or equivalent (to query the screen dimensions
  and the cursor position, and to review the current screen content and
  highlighting), and read and write access to the system console (for
  arrow key entry during cursor routing, for input character insertion
  during paste, for special key simulation using keys on the braille
  display, for retrieving output character translation and screen font
  mapping tables, and for activation of the internal beeper).  Access to
  the needed devices can, of course, be granted to a non-root user by
  changing the file permissions associated with the devices.  Merely
  having access to the console, however, isn't enough because activating
  the internal beeper and simulating key strokes still require root
  privilege.  So, if you're willing to give up Cursor Routing, Copy and
  Paste, beeps, and all that, you can run BRLTTY without root privilege.

  3.6.  Build and Run-Time Restrictions


     Alert Tunes

        Some platforms don't support all of the tune devices.  See the
        ``Tune Device'' preference for details.

     FestivalLite Speech Synthesizer Driver

        The driver for the FestivalLite text to speech engine is only
        built if that package has been installed.

        This driver and the driver for the Theta text to speech engine
        (see the ``--with-theta'' build option) cannot be simultaneously
        linked into the BRLTTY binary (see the ``--with-speech-driver''
        build option) because their run-time libraries contain
        conflicting symbols.

     Libbraille Braille Display Driver

        The driver for the Libbraille package is only built if that
        package has been installed.

     Mikropuhe Speech Synthesizer Driver

        The driver for the Mikropuhe text to speech engine is only built
        if that package has been installed.

        This driver cannot be included if the BRLTTY binary is
        statically linked (see the ``--enable-standalone-programs''
        build option) because a static archive isn't included with the
        package.

     Theta Speech Synthesizer Driver

        The driver for the Theta text to speech engine is only built if
        that package has been installed.

        This driver and the driver for the FestivalLite text to speech
        engine (see the ``--with-flite'' build option) cannot be
        simultaneously linked into the BRLTTY binary (see the ``--with-
        speech-driver'' build option) because their run-time libraries
        contain conflicting symbols.

        If this driver is built as a dynamically loadable shared object
        then $THETA_HOME/lib must be added to the LD_LIBRARY_PATH
        environment variable before BRLTTY is invoked because the shared
        objects within the package don't contain run-time search paths
        for their dependencies.

     ViaVoice Speech Synthesizer Driver

        The driver for the ViaVoice text to speech engine is only built
        if that package has been installed.

        This driver cannot be included if the BRLTTY binary is
        statically linked (see the ``--enable-standalone-programs''
        build option) because a static archive isn't included with the
        package.

     VideoBraille Braille Display Driver

        The driver for the VideoBraille braille display is built on all
        systems, but only works on Linux.

  3.7.  Installing from an RPM File

  To install BRLTTY from an RPM (RedHat Package Manager) file, do the
  following:

  1. Download the binary package which corresponds to your hardware.
     It'll be a file named brltty-release-version.architecture.rpm, e.g.
     brltty-3.0-1.i386.rpm.

  2. Install the package.

       rpm -Uvh brltty-release-version.architecture.rpm


  This should be done as root.  Strictly speaking, the -U (update) op-
  tion is the only one which is necessary.  The -v (verbose) option dis-
  plays the name of the package as it's being installed.  The -h
  (hashes) option displays a progress meter (using hash signs).

  For the brave, we also provide the source RPM (.src.rpm) file, but
  that's beyond the scope of this document.

  To uninstall BRLTTY, do:

       rpm -e brltty


  3.8.  Other Utilities

  Building BRLTTY also results in the building of a few small helper and
  diagnostic utilities.

  3.8.1.  brltty-config

  This utility sets a number of environment variables to values which
  reflect the current installation of BRLTTY (see ``Build Options'').
  It should be executed within an existing shell environment, i.e. not
  as a command in its own right, and can only be used by scripts which
  support Bourne Shell syntax.

       . brltty-config


  The following environment variables are set:

     BRLTTY_VERSION
        The version number of the BRLTTY package.

     BRLTTY_EXECUTE_ROOT
        Run-time root for the installed package.  Configured via the
        ``--with-execute-root'' build option.

     BRLTTY_PROGRAM_DIRECTORY
        Directory for runnable programs (binaries, executables).
        Configured via the ``--with-program-directory'' build option.

     BRLTTY_LIBRARY_DIRECTORY
        Directory for drivers.  Configured via the ``--with-library-
        directory'' build option.

     BRLTTY_WRITABLE_DIRECTORY
        Directory which can be written to.  Configured via the ``--with-
        writable-directory'' build option.

     BRLTTY_DATA_DIRECTORY
        Directory for tables and help pages.  Configured via the
        ``--with-data-directory'' build option.

     BRLTTY_MANPAGE_DIRECTORY
        Directory for manual pages.  Configured via the ``--with-
        manpage-directory'' build option.

     BRLTTY_INCLUDE_DIRECTORY
        Directory for BrlAPI's C header files.  Configured via the
        ``--with-include-directory'' build option.

     BRLAPI_VERSION
        The version number of BrlAPI (BRLTTY's Application Programming
        Interface).

     BRLAPI_RELEASE
        The full release number of BrlAPI.

     BRLAPI_AUTH
        The name of BrlAPI's key file.

  In addition, the following standard autoconf environment variables are
  also set:

     prefix
        Subroot for architecture-independent files.  Configured via the
        ``--prefix'' build option.

     exec_prefix
        Subroot for architecture-dependent files.  Configured via the
        ``--exec-prefix'' build option.

     bindir
        Default location for ``program directory''.  Configured via the
        --bindir build option.

     libdir
        Directory for BrlAPI's static archive and dynamically loadable
        object.  Default anchor for ``library directory''.  Configured
        via the ``--libdir'' build option.

     sysconfdir
        Directory for configuration files.  Default anchor for ``data
        directory''.  Configured via the ``--sysconfdir'' build option.

     mandir
        Default location for ``manual pages directory''.  Configured via
        the --mandir build option.

     includedir
        Default anchor for ``header files directory''.  Configured via
        the --includedir build option.

  3.8.2.  brltty-install

  This utility copies BRLTTY's ``installed file hierarchy'' from one
  location to another.

       brltty-install to [from]



     to The location to which the ``installed file hierarchy'' is to be
        copied.  It must be an existing directory.

     from
        The location from which the ``installed file hierarchy'' is to
        be taken.  If it's specified, then it must be an existing
        directory.  If it's not specified, then the location used for
        the build is assumed.

  This utility can be used, for example, to copy BRLTTY to a root disk.
  If a root floppy is mounted as /mnt, and BRLTTY is installed on the
  main system, then typing

       brltty-install /mnt


  copies BRLTTY, along with all of its data and library files, to the
  root floppy.

  Some problems have been experienced when copying BRLTTY between
  systems with different versions of the shared C library.  This is
  worth investigating if you have difficulties.

  3.8.3.  brltest

  This utility tests a braille display driver, and also provides an
  interactive way to learn what the keys on the braille display do.  It
  should be run as root.

       brltest -option ... [driver [name=value ...]]



     driver
        The driver for the braille display.  It must be a two-letter
        ``driver identification code''.  If it's not specified, then the
        first driver configured via the ``--with-braille-driver'' build
        option is assumed.

     name=value
        Set a braille display driver parameter.  For a description of
        the parameters accepted by a specific driver, please see the
        documentation for that driver.

     -ddevice --device=device
        The absolute path for the device to which the braille display is
        connected.  If it's not specified, then the device configured
        via the ``--with-braille-device'' build option is assumed.

     -Ddirectory --data-directory=directory
        The absolute path for the directory wherein the driver data
        files reside.  If it's not specified, then the directory
        configured via the ``--with-data-directory'' build option is
        assumed.

     -Ldirectory --library-directory=directory
        The absolute path for the directory wherein the drivers reside.
        If it's not specified, then the directory configured via the
        ``--libdir'' build option is assumed.

     -Wdirectory --writable-directory=directory
        The absolute path for a directory which can be written to.  If
        it's not specified, then the directory configured via the
        ``--with-writable-directory'' build option is assumed.

     -h --help
        Display a summary of the command line options, and then exit.

  This utility uses BRLTTY's ``Command Learn Mode''.  The key press
  timeout (after which this utility exits) is 10 seconds.  The message
  hold time (used for non-final segments of long messages) is 4 seconds.

  3.8.4.  spktest

  This utility tests a speech synthesizer driver.  It may need to be run
  as root.

       spktest -option ... [driver [name=value ...]]



     driver
        The driver for the speech synthesizer.  It must be a two-letter
        ``driver identification code''.  If it's not specified, then the
        first driver configured via the ``--with-speech-driver'' build
        option is assumed.

     name=value
        Set a speech synthesizer driver parameter.  For a description of
        the parameters accepted by a specific driver, please see the
        documentation for that driver.

     -tstring --text-string=string
        The text to be spoken.  If it's not specified, then standard
        input is read.

     -Ddirectory --data-directory=directory
        The absolute path for the directory wherein the driver data
        files reside.  If it's not specified, then the directory
        configured via the ``--with-data-directory'' build option is
        assumed.

     -Ldirectory --library-directory=directory
        The absolute path for the directory wherein the drivers reside.
        If it's not specified, then the directory configured via the
        ``--libdir'' build option is assumed.

     -h --help
        Display a summary of the command line options, and then exit.

  3.8.5.  scrtest

  This utility tests the screen driver.  It must be run as root.

       scrtest -option ... [name=value ...]



     name=value
        Set a screen driver parameter.  For a description of the
        parameters accepted by a specific driver, please see the
        documentation for that driver.

     -lcolumn --left=column
        Specify the starting (left) column (zero-origin) of the region.
        If this value isn't supplied, then a default value, based on the
        specified width, is selected such that the region is
        horizontally centred.

     -ccount --columns=count
        Specify the width of the region (in columns).  If this value
        isn't supplied, then a default value, based on the specified
        starting column, is selected such that the region is
        horizontally centred.

     -trow --top=row
        Specify the starting (top) row (zero-origin) of the region.  If
        this value isn't supplied, then a default value, based on the
        specified height, is selected such that the region is vertically
        centred.

     -rcount --rows=count
        Specify the height of the region (in rows).  If this value isn't
        supplied, then a default value, based on the specified starting
        row, is selected such that the region is vertically centred.

     -h --help
        Display a summary of the command line options, and then exit.

  Notes:

  ·  If neither a starting column nor a region width is specified, then
     the region is horizontally-centred and starts at column 5.

  ·  If neither a starting row nor a region height is specified, then
     the region is vertically-centred and starts at row 5.

  The following is written to standard output:

  1. A line detailing the dimensions of the screen.

       Screen: widthxheight


  2. A line detailing the position (zero-origin) of the cursor.

       Cursor: [column,row]


  3. A line detailing the size of the selected screen region, and the
     position (zero-origin) of its top-left corner.

       Region: widthxheight@[column,row]


  4. The contents of the selected screen region.  Unprintable characters
     are written as blanks.

  3.8.6.  ttbtest

  This utility tests a text table (see section ``Text Tables'').

       ttbtest -option ... input-table output-table



     input-table
        The file system path to the input text table.  If it's relative
        then it's anchored at the directory configured via the ``--with-
        data-directory'' build option.

     output-table
        The file system path to the output text table.  If it's relative
        then it's anchored at the current working directory.  If this
        parameter isn't supplied then no output table is written.

     -iformat --input-format=format
        Specify the format of the input table.  If this option isn't
        supplied then the format of the input table is deduced from the
        extension of the input table's file name.

     -oformat --output-format=format
        Specify the format of the output table.  If this option isn't
        supplied then the format of the output table is deduced from the
        extension of the output table's file name.

     -ccharset --charset=charset
        Specify the name of the 8-bit character set to use when
        interpreting the tables.  If this option isn't supplied then the
        host's character set is used.

     -e --edit
        Invoke the text table editor.  If the output table is specified
        then changes are written to it.  If not then the input table is
        rewritten.

     -h --help
        Display a summary of the command line options, and then exit.

  If no special action is requested then the output table is optional.
  If it is not specified then the input table is checked.  If it is
  specified then the input table is converted.

  The following table formats are supported:

     ttb
        BRLTTY

     sbl
        SuSE Blinux

     a2b
        Gnopernicus

     gnb
        Gnome Braille

  3.8.7.  ctbtest

  This utility tests a contraction table (see section ``Contraction
  Tables'').  The text read from the input files (or standard input) is
  rewritten to standard output as contracted braille.

       ctbtest -option ... input-file ...



     input-file
        The list of files to be processed.  Any number of files may be
        specified.  They're processed from left to right.  The special
        file name - is interpreted to mean standard input.  If no files
        are specified then standard input is processed.

     -cfile --contraction-table=file
        The file system path to the contraction table.  If it's relative
        then it's anchored at the directory configured via the ``--with-
        data-directory'' build option.  The .ctb extension is optional.
        If this option isn't supplied then en-us-g2 is assumed.

     -tfile|auto --text-table=file|auto
        Specify the text table (see section ``Text Tables'' for
        details).  If a relative path is supplied, then it's anchored at
        /etc/brltty (see the ``--with-data-directory'' and the ``--with-
        execute-root'' build options for more details).  The .ttb
        extension is optional.  See the ``text-table'' configuration
        file directive for the default run-time setting.  This setting
        can be changed with the ``Text Table'' preference.

     -wcolumns --output-width=columns
        The maximum length of an output line.  Each contracted input
        line is wrapped into as many output lines as necessary.  If this
        option isn't specified then there's no limit, and there's a one-
        to-one correspondence between input and output lines.

     -h --help
        Display a summary of the command line options, and then exit.

  The text table is used:

  ·  To define the output character set so that the contracted braille
     will be displayed correctly.  The same table as will be used by
     BRLTTY when the output is read should be specified.

  ·  To define the braille representations of those characters defined
     within the contraction table as = (see section ``Character
     Translation'').

  The brf.ttb text table is provided for use with this utility.  It
  defines the format used within .brf files.  This is also the preferred
  format used by most braille printers and within electronically
  distributed braille documents.  This table effectively allows this
  utility to be used as a text to braille translator.

  3.8.8.  tunetest

  This utility tests the alert tunes facility, and also provides an easy
  way to compose new tunes.  It may need to be run as root.

       tunetest -option ... {note duration} ...



     note
        A standard MIDI note number.  It must be an integer from 1
        through 127, with 60 representing Middle C.  Each value
        represents a standard chromatic semi-tone, with the next lower
        and higher values representing, respectively, the next lower and
        higher notes.  The lowest value (1) represents the fifth C-Sharp
        below Middle C, and the highest value (127) represents the sixth
        G above Middle C.

     duration
        The duration of the note in milliseconds.  It must be an integer
        from 1 through 255.

     -ddevice --device=device
        The device on which to play the tune.

        beeper
           The internal beeper (console tone generator).

        pcm
           The digital audio interface on the sound card.

        midi
           The Musical Instrument Digital Interface on the sound card.

        fm The FM synthesizer on an AdLib, OPL3, Sound Blaster, or
           equivalent sound card.

        The device name may be abbreviated.  See the ``Tune Device''
        preference for details regarding the default device and platform
        restrictions.

     -vloudness --volume=loudness
        Specify the output volume (loudness) as a percentage of the
        maximum.  The default output volume is 50.

     -pdevice --pcm-device=device
        Specify the device to use for digital audio (see section ``PCM
        Device Specification'').  This option isn't available if the
        ``--disable-pcm-support'' build option was specified.

     -mdevice --midi-device=device
        Specify the device to use for the Musical Instrument Digital
        Interface (see section ``MIDI Device Specification'').  This
        option isn't available if the ``--disable-midi-support'' build
        option was specified.

     -iinstrument --instrument=instrument
        The instrument to use if the selected device is midi.  For the
        complete list of instruments, see the ``MIDI Instrument Table''.
        The default instrument is an acoustic grand piano.  The words
        comprising the instrument name must be separated from one
        another by a single minus sign rather than by spaces, and any of
        the words may be abbreviated.  An acoustic grand piano, for
        example, may be specified as a-gra-pi.

     -h --help
        Display a summary of the command line options, and then exit.

  4.  Using BRLTTY

  Before starting BRLTTY, you need to set up your braille display.  In
  most cases this is done simply by connecting it to an available serial
  port, and then turning it on.  After your display has been set up, run
  BRLTTY simply by typing the command brltty at a shell prompt (this
  must be done as root).  Check the ``-d'' command line option, the
  ``braille-device'' configuration file directive, and the ``--with-
  braille-device'' build option for alternatives regarding how to tell
  BRLTTY which device your display is connected to.  Check the ``-b''
  command line option, the ``braille-driver'' configuration file
  directive, and the ``--with-braille-driver'' build option for
  alternatives regarding how to tell BRLTTY which kind of braille
  display you have.  Check the ``-B'' command line option, and the
  ``braille-parameters'' configuration file directive for alternatives
  regarding how to pass parameters to the driver for your braille
  display.

  A message giving the program name (BRLTTY) and its version number will
  appear briefly (see the ``-M'' command line option) on the braille
  display.  The display will then show a small area of the screen
  including the cursor.  By default, the cursor is represented as dots 7
  and 8 superimposed on the character it is on.

  Any screen activity will be reflected on the braille display.  The
  display will also follow the progress of the cursor on the screen.
  This feature is known as cursor tracking.

  Just typing on the keyboard and reading the display, however, isn't
  enough.  Try entering a command which will cause an error, and
  pressing enter.  The error appears on the screen, but, unless you have
  a multi-line display, the chances are that it isn't visible on the
  braille display.  All you see thereon is another shell prompt.  What's
  needed, then, is some way to move the braille window around the
  screen.  The keys on the braille display itself can be used to send
  commands to BRLTTY which, in addition to a lot of other things, can
  also do exactly that.

  4.1.  Commands

  Unfortunately, the various braille displays don't offer a standard set
  of controls.  Some have the six standard dot keys, some have eight,
  and others have none.  Some have thumb keys, but there's no standard
  number of them.  Some have a button above each braille cell.  Some
  have rocker switches.  Some have an easy-to-reach bar which works much
  like a joystick.  Most have varying combinations of the above.
  Because the nature and layout of each display is so different, please
  refer to the documentation for your particular display in order to
  find out exactly what its keys do.

  BRLTTY commands are referred to by name within this manual.  If you
  forget which key(s) on your braille display to use for a particular
  command, then refer to its driver's help page.  The main key you
  should immediately commit to memory, therefore, is the one for the
  ``HELP'' command.  Use the regular motion keys (as described below) to
  navigate the help page, and press the help key again to quit.

  4.1.1.  Vertical Motion

  See also the ``PRINDENT/NXINDENT'', and the ``PRDIFCHAR/NXDIFCHAR''
  routing key commands.

     LNUP/LNDN
        Go up/down one line.  If identical line skipping has been
        activated (see the ``SKPIDLNS'' command), then these commands,
        rather than moving exactly one line, are aliases for the
        ``PRDIFLN/NXDIFLN'' commands.

     WINUP/WINDN
        Go up/down one window.  If the window is only 1 line high then
        move 5 lines.

     PRDIFLN/NXDIFLN
        Go up/down to the nearest line with different content.  If
        identical line skipping has been activated (see the ``SKPIDLNS''
        command), then these commands, rather than skipping identical
        lines, are aliases for the ``LNUP/LNDN'' commands.

     ATTRUP/ATTRDN
        Go up/down to the nearest line with different attributes
        (character highlighting).

     TOP/BOT
        Go to the top/bottom line.

     TOP_LEFT/BOT_LEFT
        Go to the top-left/bottom-left corner.

     PRPGRPH/NXPGRPH
        Go to the nearest line of the previous/next paragraph (the first
        non-blank line beyond the nearest blank line).  The current line
        is included when searching for the inter-paragraph space.

     PRPROMPT/NXPROMPT
        Go to the previous/next command prompt.

     PRSEARCH/NXSEARCH
        Search backward/forward for the nearest occurrence of the
        character string within the cut buffer (see ``Cut and Paste'')
        which isn't within the braille window.  The search proceeds to
        the left/right, starting at the character immediately to the
        left/right of the window, and wrapping at the edge of the
        screen.  The search isn't case sensitive.

  4.1.2.  Horizontal Motion

  See also the ``SETLEFT'' routing key command.

     CHRLT/CHRRT
        Go left/right one character.

     HWINLT/HWINRT
        Go left/right half a window.

     FWINLT/FWINRT
        Go left/right one window.  These commands are particularly
        useful because they automatically wrap when they reach the edge
        of the screen.  Other features, like their ability to skip blank
        windows (see the ``SKPBLNKWINS'' command), further enhance their
        usefulness.

     FWINLTSKIP/FWINRTSKIP
        Go left/right to the nearest non-blank window.

     LNBEG/LNEND
        Go to the beginning/end of the line.

  4.1.3.  Implicit Motion

  See also the ``GOTOMARK'' routing key command.

     HOME
        Go to where the cursor is.

     BACK
        Go back to where the most recent motion command put the braille
        window.  This is an easy way to get right back to where you were
        reading after an unexpected event (like cursor tracking) moves
        the braille window at an inopportune moment.

     RETURN

        ·  If the most recent motion of the braille window was
           automatic, e.g. as a result of cursor tracking, then go back
           to where the most recent motion command put it (see the
           ``BACK'' command).

        ·  If the cursor isn't within the braille window then go to
           where the cursor is (see the ``HOME'' command).

  4.1.4.  Feature Activation

  Each of these commands has three forms: activate (turn the feature
  on), deactivate (turn the feature off), and toggle (if it's off then
  turn it on, and if it's on then turn it off).  Unless specifically
  noted, each of these features is initially off, and, when on, affects
  BRLTTY's operation as a whole.  The initial setting of some of these
  features can be changed via the ``preferences menu''.

     FREEZE
        Freeze the screen image.  BRLTTY makes a copy of the screen
        (content and attributes) as of the moment when the screen image
        is frozen, and then ignores all updating of the screen until
        it's unfrozen.  This feature makes it easy, for example, to
        sample the output of an application which writes too much too
        quickly.

     DISPMD
        Show the highlighting (the attributes) of each character within
        the braille window, rather than the characters themselves (the
        content).  This feature is useful, for example, when you need to
        locate a highlighted item.  When showing screen content, the
        text table is used (see the ``-t'' command line option, the
        ``text-table'' configuration file directive, and the ``--with-
        text-table'' build option).  When showing screen attributes, the
        attributes table is used (see the ``-a'' command line option,
        the ``attributes-table'' configuration file directive, and the
        ``--with-attributes-table'' build option).  This feature only
        affects the current virtual terminal.

     SIXDOTS
        Show characters using 6-dot, rather than 8-dot, braille.  Dots 7
        and 8 are still used by other features like cursor
        representation and highlighted character underlining.  If a
        contraction table has been selected (see the ``-c'' command line
        option and the ``contraction-table'' configuration file
        directive), then it is used.  This setting can also be changed
        with the ``Text Style'' preference.

     SLIDEWIN
        If cursor tracking (see the ``CSRTRK'' command) is on, then,
        whenever the cursor moves too close to (or beyond) either end of
        the braille window, horizontally reposition the window such that
        the cursor, while remaining on that side, is nearer the centre.
        If this feature is off, then the braille window is always
        positioned such that its left end is a multiple of its width
        from the left edge of the screen.  This setting can also be
        changed with the ``Sliding Window'' preference.

     SKPIDLNS
        Rather than explicitly moving exactly one line either up or
        down, skip past lines which have the same content as the current
        line.  This feature affects the ``LNUP/LNDN'' commands, as well
        as the line wrapping feature of the ``FWINLT/FWINRT'' and
        ``FWINLTSKIP/FWINRTSKIP'' commands.  This setting can also be
        changed with the ``Skip Identical Lines'' preference.

     SKPBLNKWINS
        Skip past blank windows when reading either forward or backward.
        This feature affects the ``FWINLT/FWINRT'' commands.  This
        setting can also be changed with the ``Skip Blank Windows''
        preference.

     CSRVIS
        Show the cursor by superimposing a dot pattern (see the
        ``CSRSIZE'' command) on top of the character where it is.  This
        feature is initially on.  This setting can also be changed with
        the ``Show Cursor'' preference.

     CSRHIDE
        Hide the cursor (see the ``CSRVIS'' command) in order to
        accurately read the character beneath it.  This feature only
        affects the current virtual terminal.

     CSRTRK
        Track (follow) the cursor.  If the cursor moves to a location
        which isn't within the braille window, then automatically move
        the braille window to the cursor's new location.  You'll usually
        want this feature turned on since it minimizes the effects of
        screen scrolling, and since, during input, the region wherein
        you're currently typing is always visible.  If this feature
        causes the braille window to jump at an inopportune moment, then
        use the ``BACK'' command to get back to where you were reading.
        You may need to turn this feature off when using an application
        which continually updates the screen while maintaining a fixed
        data layout.  This feature is initially on.  This feature only
        affects the current virtual terminal.

     CSRSIZE
        Represent the cursor with all eight dots (a solid block), rather
        than with just dots 7 and 8 (an underline).  This setting can
        also be changed with the ``Cursor Style'' preference.

     CSRBLINK
        Blink (turn on and off according to a predefined interval) the
        symbol representing the cursor (see the ``CSRVIS'' command).
        This setting can also be changed with the ``Blinking Cursor''
        preference.

     ATTRVIS
        Underline (with combinations of dots 7 and 8) highlighted
        characters.

        no underline
           White on black (normal), gray on black, white on blue, black
           on cyan.

        dots 7 and 8
           Black on white (reverse video).

        dot 8
           Everything else.

        This setting can also be changed with the ``Show Attributes''
        preference.

     ATTRBLINK
        Blink (turn on and off according to a predefined interval) the
        attribute underline (see the ``ATTRVIS'' command).  This feature
        is initially on.  This setting can also be changed with the
        ``Blinking Attributes'' preference.

     CAPBLINK
        Blink (turn on and off according to a predefined interval)
        capital (uppercase) letters.  This setting can also be changed
        with the ``Blinking Capitals'' preference.

     TUNES
        Play a short predefined tune (see ``Alert Tunes'') whenever a
        significant event occurs.  This feature is initially on.  This
        setting can also be changed with the ``Alert Tunes'' preference.

     AUTOREPEAT
        Automatically repeat a command at a regular interval after an
        initial delay while its key (combination) remains pressed.  Only
        some drivers support this functionality, the primary limitation
        being that many braille displays don't signal key presses and
        key releases as distinctly separate events.  This feature is
        initially on.  This setting can also be changed with the
        ``Autorepeat'' preference.

     AUTOSPEAK
        Automatically speak:

        ·  the new line when the braille window is moved vertically.

        ·  characters which are entered or deleted.

        ·  the character to which the cursor is moved.

        This feature is initially off.  This setting can also be changed
        with the ``Autospeak'' preference.

  4.1.5.  Mode Selection


     HELP
        Switch to the braille display driver's help page.  This is where
        you can find an on-line summary of things like what your braille
        display's keys do, and how to interpret its status cells.  Use
        the regular ``vertical'' and ``horizontal'' motion commands to
        navigate the help page.  Invoke the help command again to return
        to the screen.

     INFO
        Switch to the status display (see section ``The Status Display''
        for full details).  It presents a summary including the position
        of the cursor, the position of the braille window, and the
        states of a number of BRLTTY's features.  Invoke this command
        again to return to the screen.

     LEARN
        Switch to command learn mode (see section ``Command Learn Mode''
        for full details).  This is how you can interactively learn what
        your braille display's keys do.  Invoke this command again to
        return to the screen.  This command isn't available if the
        ``--disable-learn-mode'' build option was specified.

  4.1.6.  Preference Maintenance


     PREFMENU
        Switch to the preferences menu (see ``The Preferences Menu'' for
        full details).  Invoke this command again to return to normal
        operation.

     PREFSAVE
        Save the current preferences settings (see ``Preferences'' for
        full details).

     PREFLOAD
        Restore the most recently saved preferences settings (see
        ``Preferences'' for full details).

  4.1.7.  Menu Navigation


     MENU_FIRST_ITEM/MENU_LAST_ITEM
        Go to the first/last item in the menu.

     MENU_PREV_ITEMMENU_NEXT_ITEM/
        Go to the previous/next item in the menu.

     MENU_PREV_SETTING/MENU_NEXT_SETTING
        Decrement/increment the current menu item's setting.

  4.1.8.  Speech Controls


     SAY_LINE
        Speak the current line.  The ``Say-Line Mode'' preference
        determines if pending speech is discarded first.

     SAY_ABOVE
        Speak the top portion of the screen (ending with the current
        line).

     SAY_BELOW
        Speak the bottom portion of the screen (starting with the
        current line).

     MUTE
        Stop speaking immediately.

     SPKHOME
        Go to where the speech cursor is.

     SAY_SLOWER/SAY_FASTER
        Decrease/increase the speech rate (see also the ``Speech Rate''
        preference).  This command is only available if a driver which
        supports it is being used.

     SAY_SOFTER/SAY_LOUDER
        Decrease/increase the speech volume (see also the ``Speech
        Volume'' preference).  This command is only available if a
        driver which supports it is being used.

  4.1.9.  Speech Navigation


     SPEAK_CURR_CHAR
        a

  4.1.10.  Virtual Terminal Switching

  See also the ``SWITCHVT'' routing key command.

     SWITCHVT_PREV/SWITCHVT_NEXT
        Switch to the previous/next virtual terminal.

  4.1.11.  Other Commands


     CSRJMP_VERT
        Route (bring) the cursor to anywhere on the top line of the
        braille window (see ``Cursor Routing'' for full details).  The
        cursor is moved by simulating vertical arrow-key presses.  This
        command doesn't always work because some applications either
        move the cursor somewhat unpredictably or use the arrow keys for
        purposes other than cursor motion.  It's somewhat safer than the
        other cursor routing commands, though, because it makes no
        attempt to simulate the left- and right-arrows.

     PASTE
        Insert the characters within the cut buffer at the current
        cursor location (see ``Cut and Paste'' for full details).

     RESTARTBRL
        Stop, and then restart the braille display driver.

     RESTARTSPEECH
        Stop, and then restart the speech synthesizer driver.

  4.1.12.  Character Commands


     ROUTE
        Route (bring) the cursor to the character associated with the
        routing key (see ``Cursor Routing'' for full details).  The
        cursor is moved by simulating arrow-key presses.  This command
        doesn't always work because some applications either move the
        cursor somewhat unpredictably or use the arrow keys for purposes
        other than cursor motion.

     CUTBEGIN
        Anchor the start of the cut block at the character associated
        with the routing key (see ``Cut and Paste'' for full details).
        This command clears the cut buffer.

     CUTAPPEND
        Anchor the start of the cut block at the character associated
        with the routing key (see ``Cut and Paste'' for full details).
        This command doesn't clear the cut buffer.

     CUTRECT
        Anchor the end of the cut block at the character associated with
        the routing key, and append the rectangular region to the cut
        buffer (see ``Cut and Paste'' for full details).

     CUTLINE
        Anchor the end of the cut block at the character associated with
        the routing key, and append the linear region to the cut buffer
        (see ``Cut and Paste'' for full details).

     COPYCHARS
        Copy the character block anchored by the two routing keys to the
        cut buffer (see ``Cut and Paste'' for full details).

     APNDCHARS
        Append the character block anchored by the two routing keys to
        the cut buffer (see ``Cut and Paste'' for full details).

     PRINDENT/NXINDENT
        Go up/down to the nearest line which isn't indented more than
        the column associated with the routing key.

     DESCCHAR
        Momentarily (see the ``-M'' command line option) display a
        message describing the character associated with the routing
        key.  It reveals the decimal and hexadecimal values of the
        character, the foreground and background colours, and, when
        present, special attributes (bright and blink).  The message
        looks like this:

          char 65 (0x41): white on black bright blink


     SETLEFT
        Horizontally reposition the braille window so that its left edge
        is at the column associated with the routing key.  This feature
        makes it very easy to put the window exactly where it's needed,
        and, therefore, for displays which have routing keys, almost
        eliminates the need for a lot of elementary window motion (like
        the ``CHRLT/CHRRT'' and ``HWINLT/HWINRT'' commands).

     PRDIFCHAR/NXDIFCHAR
        Go up/down to the nearest line which has a different character
        in the column associated with the routing key.

  4.1.13.  Base Commands


     SWITCHVT
        Switch to the virtual terminal whose number (counting from 1)
        matches that of the routing key.  See also the
        ``SWITCHVT_PREV/SWITCHVT_NEXT'' virtual terminal switching
        commands.

     SETMARK
        Mark (remember) the current position of the braille window in a
        register associated with the routing key.  See the ``GOTOMARK''
        command.  This feature only affects the current virtual
        terminal.

     GOTOMARK
        Move the braille window to the position formerly marked (see the
        ``SETMARK'' command) with the same routing key.  This feature
        only affects the current virtual terminal.

  4.2.  The Configuration File

  System defaults for many settings may be established within a
  configuration file.  The default name for this file is
  /etc/brltty.conf, although it may be overridden with the ``-f''
  command line option.  It doesn't need to exist.  A template for it can
  be found within the Documents subdirectory.

  Blank lines are ignored.  A comment begins with a number sign (#), and
  continues to the end of the line.  The following directives are
  recognized:

     api-parameters name=value,...
        Specify parameters for the Application Programming Interface.
        If the same parameter is specified more than once, then its
        rightmost assignment is used.  For a description of the
        parameters accepted by the interface, please see the BrlAPI
        reference manual.  See the ``--with-api-parameters'' build
        option for the defaults established during the build procedure.
        This directive can be overridden with the ``-A'' command line
        option.

     attributes-table file
        Specify the attributes table (see section ``Attributes Tables''
        for details).  If a relative path is supplied, then it's
        anchored at /etc/brltty (see the ``--with-data-directory'' and
        the ``--with-execute-root'' build options for more details).
        The .atb extension is optional.  The default is to use the
        built-in table (see the ``--with-attributes-table'' build
        option).  This directive can be overridden with the ``-a''
        command line option.

     braille-device device,...
        Specify the device to which the braille display is connected
        (see section ``Braille Device Specification'').  See the
        ``--with-braille-device'' build option for the default
        established during the build procedure.  This directive can be
        overridden with the ``-d'' command line option.

     braille-driver driver,...|auto
        Specify the braille display driver (see section ``Driver
        Specification'').  The default is to perform autodetection.
        This directive can be overridden with the ``-b'' command line
        option.

     braille-parameters [driver:]name=value,...
        Specify parameters for the braille display drivers.  If the same
        parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Driver Identification Codes'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``--with-braille-parameters'' build option for the
        defaults established during the build procedure.  This directive
        can be overridden with the ``-B'' command line option.

     contraction-table file
        Specify the contraction table (see section ``Contraction
        Tables'' for details).  If a relative path is supplied, then
        it's anchored at /etc/brltty (see the ``--with-data-directory''
        and the ``--with-execute-root'' build options for more details).
        The .ctb extension is optional.  The contraction table is used
        when the 6-dot braille feature is activated (see the ``SIXDOTS''
        command and the ``Text Style'' preference).  The default is to
        display uncontracted 6-dot braille.  This directive can be
        overridden with the ``-c'' command line option.  It isn't
        available if the ``--disable-contracted-braille'' build option
        was specified.

     keyboard-table file|auto
        Specify the keyboard table (see section ``Key Tables'' for
        details).  If a relative path is supplied, then it's anchored at
        /etc/brltty (see the ``--with-data-directory'' and the ``--with-
        execute-root'' build options for more details).  The .ktb
        extension is optional.  The default is not to use a keyboard
        table.  This directive can be overridden with the ``-k'' command
        line option.

     keyboard-properties name=value,...
        Specify the properties of the keyboard(s) to be monitored.  If
        the same property is specified more than once, then its
        rightmost assignment is used.  See section ``Keyboard
        Properties'' for a list of the properties which may be
        specified.  The default is to monitor all keyboards.  This
        directive can be overridden with the ``-K'' command line option.

     midi-device device
        Specify the device to use for the Musical Instrument Digital
        Interface (see section ``MIDI Device Specification'').  This
        directive can be overridden with the ``-m'' command line option.
        It isn't available if the ``--disable-midi-support'' build
        option was specified.

     pcm-device device
        Specify the device to use for digital audio (see section ``PCM
        Device Specification'').  This directive can be overridden with
        the ``-p'' command line option.  It isn't available if the
        ``--disable-pcm-support'' build option was specified.

     preferences-file file
        Specify the location of the file which is to be used for the
        saving and loading of user preferences.  If a relative path is
        supplied, then it's anchored at /var/lib/brltty.  The default is
        to use brltty.prefs.  This directive can be overridden with the
        ``-F'' command line option.

     release-device boolean
        Whether or not to release the device to which the braille
        display is connected when the current screen or window can't be
        read.

        on Release the device.

        off
           Don't release the device.

        The default setting is on on Windows platforms and off on all
        other platforms.  This directive can be overridden with the
        ``-r'' command line option.

     screen-driver driver
        Specify the screen driver (see section ``Supported Screen
        Drivers'').  See the ``--with-screen-driver'' build option for
        the default established during the build procedure.  This
        directive can be overridden with the ``-x'' command line option.

     screen-parameters [driver:]name=value,...
        Specify parameters for the screen drivers.  If the same
        parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Supported Screen Drivers'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``--with-screen-parameters'' build option for the
        defaults established during the build procedure.  This directive
        can be overridden with the ``-X'' command line option.

     speech-driver driver,...|auto
        Specify the speech synthesizer driver (see section ``Driver
        Specification'').  The default is to perform autodetection.
        This directive can be overridden with the ``-s'' command line
        option.  It isn't available if the ``--disable-speech-support''
        build option was specified.

     speech-input name
        Specify the name of the file system object (FIFO, named pipe,
        named socket, etc) which can be used by other applications for
        text-to-speech conversion via BRLTTY's speech driver.  This
        directive can be overridden with the ``-i'' command line option.
        It isn't available if the ``--disable-speech-support'' build
        option was specified.

     speech-parameters [driver:]name=value,...
        Specify parameters for the speech synthesizer drivers.  If the
        same parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Driver Identification Codes'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``--with-speech-parameters'' build option for the
        defaults established during the build procedure.  This directive
        can be overridden with the ``-S'' command line option.

     text-table file|auto
        Specify the text table (see section ``Text Tables'' for
        details).  If a relative path is supplied, then it's anchored at
        /etc/brltty (see the ``--with-data-directory'' and the ``--with-
        execute-root'' build options for more details).  The .ttb
        extension is optional.  The default is to perform locale-based
        autoselection, with fallback to the built-in table (see the
        ``--with-text-table'' build option).  This directive can be
        overridden with the ``-t'' command line option.

  4.3.  Command Line Options

  Many settings can be explicitly specified when invoking BRLTTY.  The
  brltty command accepts the following options:

     -afile --attributes-table=file
        Specify the attributes table (see section ``Attributes Tables''
        for details).  If a relative path is supplied, then it's
        anchored at /etc/brltty (see the ``--with-data-directory'' and
        the ``--with-execute-root'' build options for more details).
        The .atb extension is optional.  See the ``attributes-table''
        configuration file directive for the default run-time setting.
        This setting can be changed with the ``Attributes Table''
        preference.

     -bdriver,...|auto --braille-driver=driver,...|auto
        Specify the braille display driver (see section ``Driver
        Specification'').  See the ``braille-driver'' configuration file
        directive for the default run-time setting.

     -cfile --contraction-table=file
        Specify the contraction table (see section ``Contraction
        Tables'' for details).  If a relative path is supplied, then
        it's anchored at /etc/brltty (see the ``--with-data-directory''
        and the ``--with-execute-root'' build options for more details).
        The .ctb extension is optional.  The contraction table is used
        when the 6-dot braille feature is activated (see the ``SIXDOTS''
        command and the ``Text Style'' preference).  See the
        ``contraction-table'' configuration file directive for the
        default run-time setting.  This setting can be changed with the
        ``Contraction Table'' preference.  This option isn't available
        if the ``--disable-contracted-braille'' build option was
        specified.

     -ddevice,... --braille-device=device,...
        Specify the device to which the braille display is connected
        (see section ``Braille Device Specification'').  See the
        ``braille-device'' configuration file directive for the default
        run-time setting.

     -e --standard-error
        Write diagnostic messages to standard error.  The default is to
        record them via syslog.

     -ffile --configuration-file=file
        Specify the location of the ``configuration file'' which is to
        be used for the establishing of default run-time settings.

     -h --help
        Display a summary of the command line options accepted by
        BRLTTY, and then exit.

     -iname --speech-input=name
        Specify the name of the file system object (FIFO, named pipe,
        named socket, etc) which can be used by other applications for
        text-to-speech conversion via BRLTTY's speech driver.  If not
        specified, the file system object is not created.  See the
        ``speech-input'' configuration file directive for the default
        run-time setting.  This option isn't available if the
        ``--disable-speech-support'' build option was specified.

     -kfile --keyboard-table=file
        Specify the keyboard table (see section ``Key Tables'' for
        details).  If a relative path is supplied, then it's anchored at
        /etc/brltty (see the ``--with-data-directory'' and the ``--with-
        execute-root'' build options for more details).  The .ktb
        extension is optional.  See the ``keyboard-table'' configuration
        file directive for the default run-time setting.  This setting
        can be changed with the ``Keyboard Table'' preference.

     -llevel --log-level=level
        Specify the severity threshold for diagnostic message
        generation.  The following levels are recognized.

        0  emergency

        1  alert

        2  critical

        3  error

        4  warning

        5  notice

        6  information

        7  debug

        Either the number or the name may be supplied, and the name may
        be abbreviated.  If not specified, then information is assumed
        (see the ``-q'' option for more details).

     -mdevice --midi-device=device
        Specify the device to use for the Musical Instrument Digital
        Interface (see section ``MIDI Device Specification'').  See the
        ``midi-device'' configuration file directive for the default
        run-time setting.  This option isn't available if the
        ``--disable-midi-support'' build option was specified.

     -n --no-daemon
        Specify that BRLTTY is to remain in the foreground.  If not
        specified, then BRLTTY becomes a background process (daemon)
        after initializing itself but before starting any of the
        selected drivers.

     -pdevice --pcm-device=device
        Specify the device to use for digital audio (see section ``PCM
        Device Specification'').  See the ``pcm-device'' configuration
        file directive for the default run-time setting.  This option
        isn't available if the ``--disable-pcm-support'' build option
        was specified.

     -q --quiet
        Log less information.  This option changes the default log level
        (see the ``-l'' option) to notice if either the ``-v'' or the
        ``-V'' option is specified, and to warning otherwise.

     -r --release-device
        Release the device to which the braille display is connected
        when the current screen or window can't be read.  See the
        ``release-device'' configuration file directive for the default
        run-time setting.

     -sdriver,...|auto --speech-driver=driver,...|auto
        Specify the speech synthesizer driver (see section ``Driver
        Specification'').  See the ``speech-driver'' configuration file
        directive for the default run-time setting.  This option isn't
        available if the ``--disable-speech-support'' build option was
        specified.

     -tfile --text-table=file
        Specify the text table (see section ``Text Tables'' for
        details).  If a relative path is supplied, then it's anchored at
        /etc/brltty (see the ``--with-data-directory'' and the ``--with-
        execute-root'' build options for more details).  The .ttb
        extension is optional.  See the ``text-table'' configuration
        file directive for the default run-time setting.  This setting
        can be changed with the ``Text Table'' preference.

     -v --verify
        Display the current versions of BRLTTY itself, of the server
        side of its application programming interface, and of the
        selected braille and speech drivers, and then exit.  If the
        ``-q'' option isn't specified, then also display the values of
        the options after all sources have been considered.  If more
        than one braille driver (see the ``-b'' command line option)
        and/or more than one braille device (see the ``-d'' command line
        option) has been specified then braille display autodetection is
        performed.  If more than one speech driver (see the ``-s''
        command line option) has been specified then speech synthesizer
        autodetection is performed.

     -xdriver --screen-driver=driver
        Specify the screen driver (see section ``Supported Screen
        Drivers'').  See the ``screen-driver'' configuration file
        directive for the default run-time setting.

     -Aname=value,... --api-parameters=name=value,...
        Specify parameters for the Application Programming Interface.
        If the same parameter is specified more than once, then its
        rightmost assignment is used.  For a description of the
        parameters accepted by the interface, please see the BrlAPI
        reference manual.  See the ``api-parameters'' configuration file
        directive for the default run-time settings.

     -B[driver:]name=value,... --braille-parameters=[dri-
        ver:]name=value,...
        Specify parameters for the braille display drivers.  If the same
        parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Driver Identification Codes'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``braille-parameters'' configuration file directive for
        the default run-time settings.

     -E --environment-variables
        Recognize environment variables when determining the default
        settings for unspecified command line options (see section
        ``Command Line Options'').  If this option is specified, and if
        the environment variable associated with an unspecified option
        is defined, then the value of that environment variable is used.
        The names of these environment variables are based on the long
        names of the options they correspond to:

        ·  All letters are in upper case.

        ·  Underscores (_) are used instead of minus signs (-).

        ·  The prefix BRLTTY_ is added.

        This option is particularly useful on the Linux operating system
        as it allows default settings to be passed to BRLTTY via boot
        parameters.  The following environment variables are supported:

        BRLTTY_API_PARAMETERS
           Parameters for the Application Programming Interface (see the
           ``-A'' command line option).

        BRLTTY_ATTRIBUTES_TABLE
           The attributes table (see the ``-a'' command line option).

        BRLTTY_BRAILLE_DEVICE
           The braille display device (see the ``-d'' command line
           option).

        BRLTTY_BRAILLE_DRIVER
           The braille display driver (see the ``-b'' command line
           option).

        BRLTTY_BRAILLE_PARAMETERS
           Parameters for the braille display driver (see the ``-B''
           command line option).

        BRLTTY_CONFIGURATION_FILE
           The configuration file (see the ``-f'' command line option).

        BRLTTY_CONTRACTION_TABLE
           The contraction table (see the ``-c'' command line option).

        BRLTTY_KEYBOARD_TABLE
           The keyboard table (see the ``-k'' command line option).

        BRLTTY_KEYBOARD_PROPERTIES
           The keyboard properties (see the ``-K'' command line option).

        BRLTTY_MIDI_DEVICE
           The Musical Instrument Digital Interface device (see the
           ``-m'' command line option).

        BRLTTY_PCM_DEVICE
           The digital audio device (see the ``-p'' command line
           option).

        BRLTTY_PREFERENCES_FILE
           The location of the file which is to be used for the saving
           and loading of user preferences (see the ``-F'' command line
           option).

        BRLTTY_RELEASE_DEVICE
           Whether or not to release the device to which the braille
           display is connected when the current screen or window can't
           be read (see the ``-r'' command line option).

        BRLTTY_SCREEN_PARAMETERS
           Parameters for the screen driver (see the ``-X'' command line
           option).

        BRLTTY_SPEECH_DRIVER
           The speech synthesizer driver (see the ``-s'' command line
           option).

        BRLTTY_SPEECH_INPUT
           The name of the file system object which can be used by other
           applications for text-to-speech conversion via BRLTTY's
           speech driver (see the ``-i'' command line option).

        BRLTTY_SPEECH_PARAMETERS
           Parameters for the speech synthesizer driver (see the ``-S''
           command line option).

        BRLTTY_TEXT_TABLE
           The text table (see the ``-t'' command line option).

     -Ffile --preferences-file=file
        Specify the location of the file which is to be used for the
        saving and loading of user preferences.  If a relative path is
        supplied, then it's anchored at /var/lib/brltty.  See the
        ``preferences-file'' configuration file directive for the
        default run-time setting.

     -I --install-service
        Install BRLTTY as the BrlAPI service.  This means that:

        ·  BRLTTY will be automatically started when the system is
           booted.

        ·  Applications can know that a BrlAPI server is running.

        This option is only supported on the Windows platform.

     -Kname=value,... --keyboard-properties=name=value,...
        Specify the properties of the keyboard(s) to be monitored.  If
        the same property is specified more than once, then its
        rightmost assignment is used.  See section ``Keyboard
        Properties'' for a list of the properties which may be
        specified.  See the ``keyboard-properties'' configuration file
        directive for the default run-time settings.

     -Mcsecs --message-timeout=csecs
        Specify the amount of time (in hundredths of a second) that
        BRLTTY keeps its own internally generated messages on the
        braille display.  If not specified, then 400 (4 seconds) is
        assumed.

     -N --no-api
        Disable the application programming interface.

     -Pfile --pid-file=file
        Specify the file wherein BRLTTY is to write its process
        identifier (pid).  If not specified, BRLTTY doesn't write its
        process identifier anywhere.

     -R --remove-service
        Remove the BrlAPI service.  This means that:

        ·  BRLTTY will not be automatically started when the system is
           booted.

        ·  Applications can know that no BrlAPI server is running.

        This option is only supported on the Windows platform.

     -S[driver:]name=value,... --speech-parameters=[dri-
        ver:]name=value,...
        Specify parameters for the speech synthesizer drivers.  If the
        same parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Driver Identification Codes'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``speech-parameters'' configuration file directive for
        the default run-time settings.

     -V --version
        Display the current versions of BRLTTY itself, of the server
        side of its application programming interface, and of those
        drivers which have been linked into its binary, and then exit.
        If the ``-q'' option isn't specified, then also display
        copyright information.

     -X[driver:]name=value,... --screen-parameters=[dri-
        ver:]name=value,...
        Specify parameters for the screen drivers.  If the same
        parameter is specified more than once, then its rightmost
        assignment is used.  If a parameter name is qualified by a
        driver (see section ``Supported Screen Drivers'') then that
        setting only applies to that driver; if it isn't then it applies
        to all drivers.  For a description of the parameters accepted by
        a specific driver, please see the documentation for that driver.
        See the ``screen-parameters'' configuration file directive for
        the default run-time settings.

  5.  Feature Descriptions

  5.1.  Cursor Routing

  When moving the braille window around the screen while examining the
  text, say, in an editor, you often need to bring the cursor to a
  specific character within the braille window.  You'll probably find
  this to be a rather difficult task for a number of reasons.  One is
  that you may not know where the cursor is, and that you may lose your
  place while trying to find it.  Another is that the cursor may move
  unpredictably as the arrow keys are pressed (some editors, for
  example, don't allow the cursor to be more to the right than the end
  of the line it's on).  Cursor routing provides just such a capability
  by knowing where the cursor is, by simulating the same arrow-key
  presses which you'd have to enter manually, and by monitoring the
  progress of the cursor as it moves.

  Some braille displays have a button, known as a routing key, above
  each cell.  These keys use the ``ROUTE'' command to route the cursor
  right to the desired location.

  Cursor routing, while very convenient and effective, is, strictly
  speaking, not completely reliable.  One reason for this is that its
  current implementation assumes VT100 cursor key escape sequences.
  Another is that some applications do non-standard things in response
  to detecting that a cursor key has been pressed.  A minor problem
  found within some editors (like vi), as already mentioned above, is
  that they throw in some unpredictable horizontal motion when vertical
  motion is requested because they don't allow the cursor to be to the
  right of the end of a line.  A major problem found within some web
  browsers (like lynx) is that the up- and down-arrow keys are used to
  move among the links (which may skip lines and/or move the cursor
  horizontally, but which rarely just moves the cursor one line in the
  desired direction), and that the left- and right-arrow keys are used
  to select links (which has absolutely nothing to do with any form of
  cursor motion whatsoever, and which even totally changes the screen
  content).

  Cursor routing may not work very well on a heavily loaded system, and
  definitely doesn't work very well when working on a remote system over
  a slow link.  This is so because of all of the checks which must be
  made along the way in order to deal with unpredictable cursor motion
  and in order to ensure that any mistake has at least a fighting chance
  to be undone.  Even though BRLTTY tries to be fairly clever, it must
  still essentially wait to see what happens after each simulated arrow-
  key press.

  Once a cursor routing request has been made, BRLTTY keeps trying to
  route the cursor to the desired location until a timeout expires
  before the cursor reaches that location, the cursor seems to be moving
  in the wrong direction, or you switch to a different virtual terminal.
  An attempt is first made to use vertical motion to bring the cursor to
  the right line, and, only if that succeeds, an attempt is then made to
  use horizontal motion to bring the cursor to the right column.  If
  another request is made while one is still in progress, then the first
  one is aborted and the second one is initiated.

  A safer but less powerful cursor routing command, ``CSRJMP_VERT'',
  uses just vertical motion to bring the cursor to anywhere on the top
  line of the braille window.  It's especially useful in conjunction
  with applications (like lynx) wherein horizontal cursor motion must
  never be attempted.

  5.2.  Cut and Paste

  This feature enables you to grab some text which is already on the
  screen and re-enter it at the current cursor position.  Using it saves
  time and avoids errors when a long and/or complicated piece of text
  needs to be copied, and even when the same short and simple piece of
  text needs to be copied many times.  It's particularly useful for
  things like long file names, complicated command lines, E-mail
  addresses, and URLs. Cutting and pasting text involves three simple
  steps:

  1. Mark either the top-left corner of the rectangular area or the
     beginning of the linear area on the screen which is to be grabbed
     (cut).  If your display has routing keys, then move the braille
     window so that the first character to be cut appears anywhere
     within it, and then:

     ·  invoke the ``CUTBEGIN'' command to start a new cut buffer

     ·  invoke the ``CUTAPPEND'' command to append to the existing cut
        buffer

     by pressing the key(s) associated with it and then pressing the
     routing key associated with the character.

  2. Mark either the bottom-right corner of the rectangular area or the
     end of the linear area on the screen which is to be grabbed (cut).
     If your display has routing keys, then move the braille window so
     that the last character to be cut appears anywhere within it, and
     then

     ·  invoke the ``CUTRECT'' command to cut a rectangular area

     ·  invoke the ``CUTLINE'' command to cut a linear area

     by pressing the key(s) associated with it and then pressing the
     routing key associated with the character.  Marking the end of the
     cut area appends the selected screen content to the cut buffer.
     Excess white-space is removed from the end of each line in the cut
     buffer so that unwanted trailing spaces won't be pasted back in.
     Control characters are replaced with blanks.

  3. Insert (paste) the text where it's needed.  Place the cursor over
     the character where the text is to be pasted, and invoke the
     ``PASTE'' command.  You can paste the same text any number of times
     without recutting it.  This description assumes that you're already
     in some sort of input mode.  If you paste when you're in some other
     kind of mode (like vi's command mode), then you'd better be aware
     of what the characters in the cut buffer will do.

  The cut buffer is also used by the ``PRSEARCH/NXSEARCH'' commands.

  5.3.  Pointer (Mouse) Support via GPM

  If BRLTTY is configured with the ``--enable-gpm'' build option on a
  system where the gpm application has been installed, then it'll
  interact with the pointer (mouse).

  Moving the pointer drags the braille window (see the ``Window Follows
  Pointer'' preference).  Whenever the pointer is moved beyond the edge
  of the braille window, the braille window is dragged along (one
  character at a time).  This gives the braille user another two-
  dimensional way to inspect the screen content or to quickly move the
  braille window to a desired location.  It also gives a sighted
  observer an easy way to move the braille window to something he'd like
  the braille user to read.

  gpm uses reverse video to show where the pointer is.  Underlining of
  highlighted characters (see the ``ATTRVIS'' command for details)
  should be turned on, therefore, when the braille user wishes to use
  the pointer.

  This feature also gives the braille user access to gpm's cut-and-paste
  capability.  Although you should read gpm's own documentation, here
  are some notes on how it works.

  ·  Copy the current character to the cut buffer by single-clicking the
     left button.

  ·  Copy the current word (space-delimited) to the cut buffer by
     double-clicking the left button.

  ·  Copy the current line to the cut buffer by tripple-clicking the
     left button.

  ·  Copy a linear region to the cut buffer as follows:

     1. Place the pointer on the first character of the region.

     2. Press (and hold) the left button.

     3. Move the pointer to the last character of the region (all
        currently selected characters are highlighted).

     4. Release the left button.

  ·  Paste (input) the current contents of the cut buffer by clicking
     the middle button of a three-button mouse or by clicking the right
     button of a two-button mouse.

  ·  Append to the cut buffer by using the right button of a three-
     button mouse.

  5.4.  Alert Tunes

  BRLTTY alerts you to the occurrence of significant events by playing
  short predefined tunes.  This feature can be activated and deactivated
  with either the ``TUNES'' command or the ``Alert Tunes'' preference.
  The tunes are played via the internal beeper by default, but other
  alternatives can be selected with the ``Tune Device'' preference.

  Each significant event is associated, from highest to lowest priority,
  with one or more of the following:

     a tune
        If a tune has been associated with the event, if the ``Alert
        Tunes'' preference (see also the ``TUNES'' command) is active,
        and if the selected tune device (see the ``Tune Device''
        preference) can be opened, then the tune is played.

     a dot pattern
        If a dot pattern has been associated with the event, and if the
        ``Alert Dots'' preference is active, then the dot pattern is
        briefly displayed on every braille cell.  Some braille displays
        don't respond quickly enough for this mechanism to work
        effectively.

     a message
        If a message has been associated with the event, and if the
        ``Alert Messages'' preference is active, then it is displayed
        for a few seconds (see the ``-M'' command line option).

  These events include:

  ·  When the braille display driver starts or stops.

  ·  When a lengthy command completes.

  ·  When a command cannot be executed.

  ·  When a mark is set.

  ·  When the start or end of the cut block is set.

  ·  When a feature is activated or deactivated.

  ·  When cursor tracking is turned on or off.

  ·  When the screen image is frozen or unfrozen.

  ·  When the braille window wraps either down to the beginning of the
     next line or up to the end of the previous line.

  ·  When identical lines are skipped.

  ·  When a requested motion cannot be performed.

  ·  When cursor routing starts, finishes, or fails.

  5.5.  Preferences Settings

  When BRLTTY starts, it loads a file which contains your preferences
  settings.  The file doesn't need to exist, and is created the first
  time the settings are saved with the ``PREFSAVE'' command.  The most
  recently saved settings can be restored at any time with the
  ``PREFLOAD'' command.

  The name for this file is /etc/brltty-driver.prefs.  where driver is
  the two-letter ``driver identification code''.

  5.5.1.  The Preferences Menu

  The preferences settings are saved as binary data which, therefore,
  can't be edited by hand.  BRLTTY, however, has a simple menu from
  which you can easily change them.

  The menu is activated by the ``PREFMENU'' command.  The braille
  display briefly (see the ``-M'' command line option) shows the menu
  title, and then presents the current item and its current setting.

  5.5.1.1.  Navigating the Menu

  See ``Menu Navigation Commands'' for the full list of commands which
  enable you to select items and change settings within the menu.  For
  backward compatibility with old drivers, the window motion commands,
  which have modified meanings in this context, can also be used.

     TOP/BOT, TOP_LEFT/BOT_LEFT, PAGE_UP/PAGE_DOWN
        Go to the first/last item in the menu (same as
        ``MENU_FIRST_ITEM/MENU_LAST_ITEM'').

     LNUP/LNDN, PRDIFLN/NXDIFLN, CURSOR_UP/CURSOR_DOWN
        Go to the previous/next item in the menu (same as
        ``MENU_PREV_ITEM/MENU_NEXT_ITEM'').

     WINUP/WINDN, CHRLT/CHRRT, CURSOR_LEFT/CURSOR_RIGHT, BACK/HOME
        Decrement/increment the current menu item's setting (same as
        ``MENU_PREV_SETTING/MENU_NEXT_SETTING'').

  Notes:

  ·  The routing keys can also be used to select a setting for the
     current item.  If the item has numeric settings, then the entire
     row of routing keys acts as a scroll bar which covers the full
     range of valid values.  If the item has named settings, then the
     routing keys correspond ordinally with the settings.

  ·  Use the PREFLOAD command to undo all of the changes which were made
     since entering the menu.

  ·  Use the PREFMENU command (again) to leave the new settings in
     effect, exit the menu, and resume normal operation.  If the "Save
     Settings on Exit" item is set, then, in addition, the new settings
     are written to the preferences settings file.  Any command not
     recognized by the menu system also does these same things.

  5.5.1.2.  The Menu Items


     Save on Exit
        When exiting the preferences menu:

        No Don't automatically save the preferences settings.

        Yes
           Automatically save the preferences settings.

        The initial setting is No.

     Text Style
        When displaying screen content (see the ``DISPMD'' command),
        show characters:

        8-dot
           With all eight dots.

        6-dot
           With only dots 1 through 6.  If a contraction table has been
           selected (see the ``-c'' command line option and the
           ``contraction-table'' configuration file directive), then it
           is used.

        This setting can also be changed with the ``SIXDOTS'' command.

     Skip Identical Lines
        When moving either up or down exactly one line with the
        ``LNUP/LNDN'' commands, as well as the line wrapping feature of
        the ``FWINLT/FWINRT'' and ``FWINLTSKIP/FWINRTSKIP'' commands:

        No Don't skip past lines which have the same content as the
           current line.

        Yes
           Skip past lines which have the same content as the current
           line.

        This setting can also be changed with the ``SKPIDLNS'' command.

     Skip Blank Windows
        When moving either left or right with the ``FWINLT/FWINRT''
        commands:

        No Don't skip past blank windows.

        Yes
           Skip past blank windows.

        This setting can also be changed with the ``SKPBLNKWINS'' com-
        mand.

     Which Blank Windows
        If blank windows are to be skipped:

        All
           Skip all of them.

        End of Line
           Only skip those which are at the end (on the right side) of a
           line.

        Rest of Line
           Only skip those which are at the end (on the right side) of a
           line when reading forward, and at the beginning (on the left
           side) of a line when reading backward.

     Sliding Window
        If the cursor is being tracked (see the ``CSRTRK'' command), and
        the cursor moves too close to (or beyond) either end of the
        braille window:

        No Horizontally reposition the window such that its left end is
           a multiple of its width from the left edge of the screen.

        Yes
           Horizontally reposition the window such that the cursor,
           while remaining on that side of the window, is nearer the
           centre.

        This setting can also be changed with the ``SLIDEWIN'' command.

     Eager Sliding Window
        If the braille window is to slide:

        No Reposition it whenever the cursor moves beyond either end.

        Yes
           Reposition it whenever the cursor moves too close to either
           end.

        The initial setting is No.

     Window Overlap
        When moving either left or right with the ``FWINLT/FWINRT''
        commands, this setting specifies how many characters
        horizontally adjacent braille windows should overlap each other
        by.  The initial setting is 0.

     Autorepeat
        While the key (combination) for a command remains pressed:

        No Don't automatically repeat the command.

        Yes
           Automatically repeat the command at a regular interval after
           an initial delay.

        The following commands are eligible for autorepeating:

        ·  The ``LNUP/LNDN'' commands.

        ·  The ``PRDIFLN/NXDIFLN'' commands.

        ·  The ``CHRLT/CHRRT'' commands.

        ·  Braille window panning operations (see the ``Autorepeat
           Panning'' preference).

        ·  The Page-Up and Page-Down operations.

        ·  The Cursor-Up and Cursor-Down operations.

        ·  The Cursor-Left and Cursor-Right operations.

        ·  The Backspace and Delete operations.

        ·  Character entry.

        Only some drivers support this functionality, the primary limi-
        tation being that many braille displays don't signal both key
        presses and key releases as distinctly separate events.  This
        setting can also be changed with the ``AUTOREPEAT'' command.
        The initial setting is Yes.

     Autorepeat Panning
        When the ``Autorepeat'' preference is enabled:

        No Don't autorepeat braille window panning operations.

        Yes
           Autorepeat braille window panning operations.

        This preference affects the ``FWINLT/FWINRT'' commands.  The
        initial setting is No.

     Autorepeat Delay
        When a character is to be autorepeated, this setting specifies
        the amount of time (see the note on ``time settings'' below)
        which must pass before autorepeating begins.  The initial
        setting is 50.

     Autorepeat Interval
        When a character is being autorepeated, this setting specifies
        the amount of time (see the note on ``time settings'' below)
        between each reexecution.  The initial setting is 10.

     Show Cursor
        When displaying screen content (see the ``DISPMD'' command):

        No Don't show the cursor.

        Yes
           Show the cursor.

        This setting can also be changed with the ``CSRVIS'' command.
        The initial setting is Yes.

     Cursor Style
        When showing the cursor, represent it:

        Underline
           With dots 7 and 8.

        Block
           With all eight dots.

        This setting can also be changed with the ``CSRSIZE'' command.

     Blinking Cursor
        When the cursor is to be shown:

        No Leave it visible all the time.

        Yes
           Make it alternately visible and invisible according to a
           predefined interval.

        This setting can also be changed with the ``CSRBLINK'' command.

     Cursor Visible Time
        When the cursor is to be blinked, this setting specifies the
        length of time (see the note on ``time settings'' below) during
        each cycle that it is to be visible.  The initial setting is 40.

     Cursor Invisible Time
        When the cursor is to be blinked, this setting specifies the
        length of time (see the note on ``time settings'' below) during
        each cycle that it is to be invisible.  The initial setting is
        40.

     Show Attributes
        When displaying screen content (see the ``DISPMD'' command):

        No Don't underline highlighted characters.

        Yes
           Underline highlighted characters.

        This setting can also be changed with the ``ATTRVIS'' command.

     Blinking Attributes
        When highlighted characters are to be underlined:

        No Leave the indicator visible all the time.

        Yes
           Make the indicator alternately visible and invisible
           according to a predefined interval.

        This setting can also be changed with the ``ATTRBLINK'' command.

     Attributes Visible Time
        When the highlighted character underline is to be blinked, this
        setting specifies the length of time (see the note on ``time
        settings'' below) during each cycle that it is to be visible.
        The initial setting is 20.

     Attributes Invisible Time
        When the highlighted character underline is to be blinked, this
        setting specifies the length of time (see the note on ``time
        settings'' below) during each cycle that it is to be invisible.
        The initial setting is 60.

     Blinking Capitals
        When displaying screen content (see the ``DISPMD'' command):

        No Leave capital letters visible all the time.

        Yes
           Make capital letters alternately visible and invisible
           according to a predefined interval.

        This setting can also be changed with the ``CAPBLINK'' command.

     Capitals Visible Time
        When capital letters are to be blinked, this setting specifies
        the length of time (see the note on ``time settings'' below)
        during each cycle that they're to be visible.  The initial
        setting is 60.

     Capitals Invisible Time
        When capital letters are to be blinked, this setting specifies
        the length of time (see the note on ``time settings'' below)
        during each cycle that they're to be invisible.  The initial
        setting is 20.

     Braille Firmness
        Adjust the firmness (or stiffness) of the braille dots.  It can
        be set to:

        ·  Maximum

        ·  High

        ·  Medium

        ·  Low

        ·  Minimum

        This preference is only available if a driver which supports it
        is being used.  The initial setting is Medium.

     Braille Sensitivity
        Adjust the sensitivity of the braille dots to touch.  It can be
        set to:

        ·  Maximum

        ·  High

        ·  Medium

        ·  Low

        ·  Minimum

        This preference is only available if a driver which supports it
        is being used.  The initial setting is Medium.

     Window Follows Pointer
        When moving the pointer device (mouse):

        No Don't drag the braille window.

        Yes
           Drag the braille window.

        This preference is only presented if the ``--enable-gpm'' build
        option was specified.

     Highlight Window
        When moving the braille window:

        No Don't highlight the new screen area.

        Yes
           Highlight the new screen area.

        This feature enables a sighted observer to see where the braille
        window is, and, therefore, to know what the braille user is
        reading.  Any motion of the braille window (manual, cursor
        tracking, etc.), other than when it moves in response to pointer
        (mouse) motion (see the ``Window Follows Pointer'' preference),
        causes the area of the screen corresponding to the new location
        of the braille window to be highlighted.  If the ``Show Attrib-
        utes'' preference is enabled then only the character correspond-
        ing to the upper-left corner of the braille window is high-
        lighted.

     Alert Tunes
        Whenever a significant event with an associated tune occurs (see
        ``Alert Tunes''):

        No Don't play the tune.

        Yes
           Play the tune.

        This setting can also be changed with the ``TUNES'' command.
        The initial setting is Yes.

     Tune Device
        Play alert tunes via:

        Beeper
           The internal beeper (console tone generator).  This setting
           is supported on Linux, on OpenBSD, on FreeBSD, and on NetBSD.
           It's always safe to use, although it may be somewhat soft.
           This device isn't available if the ``--disable-beeper-
           support'' build option was specified.

        PCM
           The digital audio interface on the sound card.  This setting
           is supported on Linux (via /dev/dsp), on Solaris (via
           /dev/audio), on OpenBSD (via /dev/audio0), on FreeBSD (via
           /dev/dsp), and on NetBSD (via /dev/audio0).  It doesn't work
           when this device is already being used by another
           application.  This device isn't available if the ``--disable-
           pcm-support'' build option was specified.

        MIDI
           The Musical Instrument Digital Interface on the sound card
           This setting is supported on Linux (via /dev/sequencer).  It
           doesn't work when this device is already being used by
           another application.  This device isn't available if the
           ``--disable-midi-support'' build option was specified.

        FM The FM synthesizer on an AdLib, OPL3, Sound Blaster, or
           equivalent sound card.  This setting is supported on Linux.
           It works even if the FM synthesizer is already being used by
           another application.  The results are unpredictable, and
           potentially not very good, if it's used with a sound card
           which doesn't support this feature.  This device isn't
           available if the ``--disable-fm-support'' build option was
           specified.

        The initial setting is Beeper on those platforms which support
        it, and PCM on those platforms which don't.

     PCM Volume
        If the digital audio interface of the sound card is being used
        to play the alert tunes, this setting specifies the loudness (as
        a percentage of the maximum) at which they are to be played.
        The initial setting is 70.

     MIDI Volume
        If the Musical Instrument Digital Interface (MIDI) of the sound
        card is being used to play the alert tunes, this setting
        specifies the loudness (as a percentage of the maximum) at which
        they are to be played.  The initial setting is 70.

     MIDI Instrument
        If the Musical Instrument Digital Interface (MIDI) of the sound
        card is being used to play the alert tunes, this setting
        specifies which instrument is to be used (see the ``MIDI
        Instrument Table'').  The initial setting is Acoustic Grand
        Piano.

     FM Volume
        If the FM synthesizer of the sound card is being used to play
        the alert tunes, this setting specifies the loudness (as a
        percentage of the maximum) at which they are to be played.  The
        initial setting is 70.

     Alert Dots
        Whenever a significant event with an associated dot pattern
        occurs (see ``Alert Tunes''):

        No Don't display the dot pattern.

        Yes
           Briefly display the dot pattern.

        If alert tunes are to be played (see the ``TUNES'' command and
        the ``Alert Tunes'' preference), if a tune has been associated
        with the event, and if the selected tune device can be opened,
        then, regardless of the setting of this preference, the dot pat-
        tern isn't displayed.

     Alert Messages
        Whenever a significant event with an associated message occurs
        (see ``Alert Tunes''):

        No Don't display the message.

        Yes
           Display the message.

        If alert tunes are to be played (see the ``TUNES'' command and
        the ``Alert Tunes'' preference), if a tune has been associated
        with the event, and if the selected tune device can be opened,
        or if alert dot patterns are to be displayed (see the ``Alert
        Dots'' preference) and if a dot pattern has been associated with
        the event, then, regardless of the setting of this preference,
        the message isn't displayed.

     Say-Line Mode
        When using the ``SAY_LINE'' command:

        Immediate
           Discard pending speech.

        Enqueue
           Don't discard pending speech.

        The initial setting is Immediate.

     Autospeak

        No Only speak when explicitly requested to do so.

        Yes
           Automatically speak:

           ·  the new line when the braille window is moved vertically.

           ·  characters which are entered or deleted.

           ·  the character to which the cursor is moved.

        This setting can also be changed with the ``AUTOSPEAK'' command.
        The initial setting is No.

     Speech Rate
        Adjust the speech rate (0 is the slowest, 20 is the fastest).
        This preference is only available if a driver which supports it
        is being used.  This setting can also be changed with the
        ``SAY_SLOWER/SAY_FASTER'' commands.  The initial setting is 10.

     Speech Volume
        Adjust the speech volume (0 is the softest, 20 is the loudest).
        This preference is only available if a driver which supports it
        is being used.  This setting can also be changed with the
        ``SAY_SOFTER/SAY_LOUDER'' commands.  The initial setting is 10.

     Speech Pitch
        Adjust the speech pitch (0 is the lowest, 20 is the highest).
        This preference is only available if a driver which supports it
        is being used.  The initial setting is 10.

     Speech Punctuation
        Adjust the amount of punctuation which is spoken.  It can be set
        to:

        ·  None

        ·  Some

        ·  All

        This preference is only available if a driver which supports it
        is being used.  The initial setting is Some.

     Status Style
        This setting specifies the way that the status cells are to be
        used.  You shouldn't normally need to play with it.  It enables
        BRLTTY's developers to test status cell configurations for
        braille displays which they don't actually have.

        None
           Don't use the status cells.  This setting is always safe, but
           it's also quite useless.

        Alva
           The status cells contain:

           1  The location of the cursor (see below).

           2  The location of the top-left corner of the braille window
              (see below).

           3  A letter indicating BRLTTY's state.  In order of
              precedence:

              a  Screen attributes are being shown (see the ``DISPMD''
                 command).

              f  The screen image is frozen (see the ``FREEZE''
                 command).

              f  The cursor is being tracked (see the ``CSRTRK''
                 command).

              blank
                 Nothing special.

           The locations of the cursor and the braille window are pre-
           sented in an interesting way.  Dots 1 through 6 represent the
           line number with a letter from a (for 1) through y (for 25).
           Dots 7 and 8 (the extra two at the bottom) represent the hor-
           izontal braille window number as follows:

           No Dots
              The first (leftmost) window.

           Dot 7
              The second window.

           Dot 8
              The third window.

           Dots 7 and 8
              The fourth window.

           In both cases, the indicators wrap: line 26 is represented by
           the letter a, and the fifth horizontal braille window is rep-
           resented by no dots at the bottom.

        Tieman
           The status cells contain:

           1-2
              The columns (counting from 1) of the cursor (shown in the
              top half of the cells) and the top-left corner of the
              braille window (shown in the bottom half of the cells).

           3-4
              The rows (counting from 1) of the cursor (shown in the top
              half of the cells) and the top-left corner of the braille
              window (shown in the bottom half of the cells).

           5  Each dot indicates if a feature is turned on as follows:

              Dot 1
                 The screen image is frozen (see the ``FREEZE''
                 command).

              Dot 2
                 Screen attributes are being displayed (see the
                 ``DISPMD'' command).

              Dot 3
                 Alert tunes are being played (see the ``TUNES''
                 command).

              Dot 4
                 The cursor is being shown (see the ``CSRVIS'' command).

              Dot 5
                 The cursor is a solid block (see the ``CSRSIZE''
                 command).

              Dot 6
                 The cursor is blinking (see the ``CSRBLINK'' command).

              Dot 7
                 The cursor is being tracked (see the ``CSRTRK''
                 command).

              Dot 8
                 The braille window will slide (see the ``SLIDEWIN''
                 command).

        PowerBraille 80
           The status cells contain:

           1  The row (counting from 1) corresponding to the top of the
              braille window.  The tens digit is shown in the top half
              of the cell, and the units digit is shown in the bottom
              half of the cell.

        Generic
           This setting passes a lot of information to the braille
           driver, and the driver itself decides how to present it.

        MDV
           The status cells contain:

           1-2
              The location of the top-left corner of the braille window.
              The row (counting from 1) is shown in the top half of the
              cells, and the column (counting from 1) is shown in the
              bottom half of the cells.

        Voyager
           The status cells contain:

           1  The row (counting from 1) corresponding to the top of the
              braille window (see below).

           2  The row (counting from 1) whereon the cursor is (see
              below).

           3  If the screen is frozen (see the ``FREEZE'' command), then
              the letter F.  If it isn't, then the column (counting from
              1) wherein the cursor is (see below).

           Row and column numbers are shown as two digits within a sin-
           gle cell.  The tens digit is shown in the top half of the
           cell, and the units digit is shown in the bottom half of the
           cell.

        The initial setting is braille display driver dependent.

     Text Table
        Select the text table.  See section ``Text Tables'' for details.
        See the ``-t'' command line option for the initial setting.
        This preference isn't saved.

     Attributes Table
        Select the attributes table.  See section ``Attributes Tables''
        for details.  See the ``-a'' command line option for the initial
        setting.  This preference isn't saved.

     Contraction Table
        Select the contraction table.  See section ``Contraction
        Tables'' for details.  See the ``-c'' command line option for
        the initial setting.  This preference isn't saved.

     Keyboard Table
        Select the keyboard table.  See section ``Key Tables'' for
        details.  See the ``-k'' command line option for the initial
        setting.  This preference isn't saved.

  Notes:

  ·   All time settings are in hundredths of a second.  They are
     multiples of 4 within the range 1 through 100.

  5.6.  The Status Display

  The status display is a summary of BRLTTY's current state which fits
  completely within the braille window.  Some braille displays have a
  set of status cells which are used to permanently display some of this
  information as well (see the documentation for your display's driver).
  The data presented by this display isn't static, and may change at any
  time in response to screen updates and/or BRLTTY commands.

  Use the ``INFO'' command to switch to the status display, and use it
  again to return to the screen.  The layout of the information
  contained therein is dependent on the size of the braille window.

  5.6.1.  Displays with 21 Cells or More

  Short pneumonics have been used, even though they're rather cryptic,
  in order to show the precise column layout.

       wx:wy cx:cy vt tcmfdu



     wx:wy
        The column and row (counting from 1) on the screen corresponding
        to the top-left corner of the braille window.

     cx:cy
        The column and row (counting from 1) on the screen corresponding
        to the position of the cursor.

     vt The number (counting from 1) of the current virtual terminal.

     t  The state of the cursor tracking feature (see the ``CSRTRK''
        command).

        blank
           Cursor tracking is off.

        t  Cursor tracking is on.

     c  The state of the cursor visibility features (see the ``CSRVIS''
        and ``CSRBLINK'' commands).

        blank
           The cursor isn't visible, and won't blink when made visible.

        b  The cursor isn't visible, and will blink when made visible.

        v  The cursor is visible, and isn't blinking.

        B  The cursor is visible, and is blinking.

     m  The current display mode (see the ``DISPMD'' command).

        t  Screen content (text) is being displayed.

        a  Screen highlighting (attributes) is being displayed.

     f  The state of the frozen screen feature (see the ``FREEZE''
        command).

        blank
           The screen isn't frozen.

        f  The screen is frozen.

     d  The number of braille dots being used to display each character
        (see the ``SIXDOTS'' command).

        8  All eight dots are being used.

        6  Only dots 1 through 6 are being used.

     u  The state of the uppercase (capital letter) display features
        (see the ``CAPBLINK'' command).

        blank
           Uppercase letters don't blink.

        B  Uppercase letters blink.

  5.6.2.  Displays with 20 Cells or Less

  Short pneumonics have been used, even though they're rather cryptic,
  in order to show the precise column layout.

       xxyys vt tcmfdu



     xx The columns (counting from 1) on the screen corresponding to the
        position of the cursor (shown in the top half of the cells) and
        to the top-left corner of the braille window (shown in the
        bottom half of the cells).

     yy The rows (counting from 1) on the screen corresponding to the
        position of the cursor (shown in the top half of the cells) and
        to the top-left corner of the braille window (shown in the
        bottom half of the cells).

     s  The settings of some of BRLTTY's features.  A feature is turned
        on if its corresponding dot is raised.

        Dot 1
           Frozen screen image (see the ``FREEZE'' command).

        Dot 2
           Display attributes (see the ``DISPMD'' command).

        Dot 3
           Alert tunes (see the ``TUNES'' command).

        Dot 4
           Visible cursor (see the ``CSRVIS'' command).

        Dot 5
           Block cursor (see the ``CSRSIZE'' command).

        Dot 6
           Blinking cursor (see the ``CSRBLINK'' command).

        Dot 7
           Cursor tracking (see the ``CSRTRK'' command).

        Dot 8
           Sliding window (see the ``SLIDEWIN'' command).

     vt The number (counting from 1) of the current virtual terminal.

     t  The state of the cursor tracking feature (see the ``CSRTRK''
        command).

        blank
           Cursor tracking is off.

        t  Cursor tracking is on.

     c  The state of the cursor visibility features (see the ``CSRVIS''
        and ``CSRBLINK'' commands).

        blank
           The cursor isn't visible, and won't blink when made visible.

        b  The cursor isn't visible, and will blink when made visible.

        v  The cursor is visible, and isn't blinking.

        B  The cursor is visible, and is blinking.

     m  The current display mode (see the ``DISPMD'' command).

        t  Screen content (text) is being displayed.

        a  Screen highlighting (attributes) is being displayed.

     f  The state of the frozen screen feature (see the ``FREEZE''
        command).

        blank
           The screen isn't frozen.

        f  The screen is frozen.

     d  The number of braille dots being used to display each character
        (see the ``SIXDOTS'' command).

        8  All eight dots are being used.

        6  Only dots 1 through 6 are being used.

     u  The state of the uppercase (capital letter) display features
        (see the ``CAPBLINK'' command).

        blank
           Uppercase letters don't blink.

        B  Uppercase letters blink.

  5.7.  Command Learn Mode

  Command learn mode is an interactive way to learn what the keys on the
  braille display do.  It can be accessed either by the ``LEARN''
  command or via the ``brltest'' utility.  This feature isn't available
  if the ``--disable-learn-mode'' build option was specified.

  When this mode is entered, the message command learn mode is written
  to the braille display.  Then, as each key (or key combination) on the
  display is pressed, a short message describing its BRLTTY function is
  written.  This mode exits immediately if the key (or key combination)
  for the ``LEARN'' command is pressed.  It exits automatically, and the
  message done is written, if ten seconds elapse without any key on the
  display being pressed.  Note that some displays don't signal the
  driver and/or some drivers don't signal BRLTTY until all the keys are
  released.

  If a message is longer than the braille display is wide, then it's
  displayed in segments.  The length of each segment but the last is one
  less than the display's width, with the rightmost character on the
  display being set to a minus sign.  Each such segment remains on the
  display either for a few seconds (see the ``-M'' command line option)
  or until any key on the display is pressed.

  6.  Tables

  6.1.  Text Tables

  Files with names of the form *.ttb are text tables, and with names of
  the form *.tti are text subtables.  They are used by BRLTTY to
  translate the characters on the screen into their corresponding 8-dot
  computer braille representations.

  BRLTTY is initially configured to use the ``North American Braille
  Computer Code'' (NABCC) text table.  In addition to this default, the
  following alternatives are provided:

    Name         Language
    auto         locale-based autoselection
    ar           Arabic (generic)
    as           Assamese
    awa          Awadhi
    bg           Bulgarian
    bh           Bihari
    bn           Bengali
    bo           Tibetan
    bra          Braj
    brf          Braille Ready Format
                 (for viewing .brf files within an editor or pager)
    cs           Czech
    cy           Welsh
    da           Danish
    da-1252      Danish (Svend Thougaard, 2002-11-18)
    da-lt        Danish (LogText)
    de           German
    dra          Dravidian
    el           Greek
    en           English
    en_CA        English (Canada)
    en_GB        English (United Kingdom)
    en_US        English (United States)
    en-nabcc     English (North American Braille Computer Code)
    eo           Esperanto
    es           Spanish
    et           Estonian
    fi           Finnish
    fr           French
    fr_CA        French (Canada)
    fr_FR        French (France)
    fr-2007      French (unified 2007)
    fr-cbifs     French (Code Braille Informatique FranÃ§ais Standard)
    fr-vs        French (VisioBraille)
    ga           Irish
    gd           Gaelic
    gon          Gondi
    gu           Gujarati
    he           Hebrew
    hi           Hindi
    hr           Croatian
    hu           Hungarian
    hy           Armenian
    is           Icelandic
    it           Italian
    kha          Khasi
    kn           Kannada
    kok          Konkani
    kru          Kurukh
    lt           Lituanian
    lv           Latvian
    mg           Malagasy
    mi           Maori
    ml           Malayalam
    mni          Manipuri
    mr           Marathi
    mt           Maltese
    mun          Munda
    mwr          Marwari
    ne           Nepali
    new          Newari
    nl           Dutch
    nl_BE        Dutch (Belgium)
    nl_NL        Dutch (Netherlands)
    no           Norwegian
    no-generic   Norwegian (with support for other languages)
    no-oup       Norwegian (Offentlig utvalg for punktskrift)
    nwc          Newari (old)
    or           Oriya
    pa           Panjabi
    pi           Pali
    pl           Polish
    pt           Portuguese
    ro           Romanian
    ru           Russian
    sa           Sanskrit
    sat          Santali
    sd           Sindhi
    se           Sami (Northern)
    sk           Slovak
    sl           Slovenian
    sv           Swedish
    sv-1989      Swedish (1989 standard)
    sv-1996      Swedish (1996 standard)
    sw           Swahili
    ta           Tamil
    te           Telugu
    tr           Turkish
    uk           Ukrainian
    vi           Vietnamese


  See the ``-t'' command line option, the ``text-table'' configuration
  file directive, and the ``--with-text-table'' build option for details
  regarding how to use an alternate text table.

  6.1.1.  Text Table Format

  A text table consists of a sequence of directives, one per line, which
  define how each character is to be represented in braille.  UTF-8
  character encoding must be used.  White-space (blanks, tabs) at the
  beginning of a line, as well as before and/or after any operand of any
  directive, is ignored.  Lines containing only white-space are ignored.
  If the first non-white-space character of a line is "#" then that line
  is a comment and is ignored.

  6.1.2.  Text Table Directives

  The following directives are provided:

     char character dots # comment
        Use the char directive to specify how a Unicode character is to
        be represented in braille.  Characters defined with this
        directive can also be entered from a braille keyboard.  If
        several characters have the same braille representation then
        only one of them should be defined with the char directive - the
        others should be defined with the glyph directive (which has the
        same syntax).  If more than one character with the same braille
        representation is defined with the char directive (which is
        currently allowed for backward compatibility) then the first one
        is selected.


        character
           The Unicode character being defined.  It may be:

           ·  Any single character other than a backslash or a white-
              space character.

           ·  A backslash-prefixed special character.  These are:

                 -

              \b The backspace character.  -

              \f The formfeed character.  -

              \n The newline character.  -

              \o###
                 The three-digit octal representation of a character.  -

              \r The carriage return character.  -

              \s The space character.  -

              \t The horizontal tab character.  -

              \u####
                 The four-digit hexadecimal representation of a
                 character.  -

              \U########
                 The eight-digit hexadecimal representation of a
                 character.  -

              \v The vertical tab character.  -

              \x##
                 The two-digit hexadecimal representation of a
                 character.  -

              \X##
                 ... (the case of the X and of the digits isn't
                 significant) -

              \# A literal number sign.  -

              \<name>
                 The Unicode name of a character (use _ for space).  -

              \\ A literal backslash.

        dots
           The braille representation of the Unicode character.  It is a
           sequence of one to eight dot numbers.  If the dot number
           sequence is enclosed within parentheses then the dot numbers
           may be separated from one another by white-space.  A dot
           number is a digit within the range 1-8 as defined by the
           ``Standard Braille Dot Numbering Convention''.  The special
           dot number 0 is recognized when not enclosed within
           parentheses, and means no dots; it may not be used in
           conjunction with any other dot number.

        Examples:

        ·  char a 1

        ·  char b (12)

        ·  char c ( 4 1 )

        ·  char \\ 12567

        ·  char \s 0

        ·  char \x20 ()

        ·  char \<LATIN_SMALL_LETTER_D> 145

     glyph character dots # comment
        Use the glyph directive to specify how a Unicode character is to
        be represented in braille.  Characters defined with this
        directive are output-only.  They cannot be entered from a
        braille keyboard.

        See the char directive for syntax details and for examples.

     byte byte dots # comment
        Use the byte directive to specify how a character in the local
        character set is to be represented in braille.  It has been
        retained for backward compatibility but should not be used.
        Unicode characters should be defined (via the char directive) so
        that the text table remains valid regardless of what the local
        character set is.


        byte
           The local character being defined.  It may be specified in
           the same ways as the character operand of the char directive
           except that the Unicode-specific forms (\u, \U, \<) may not
           be used.

        dots
           The braille representation of the local character.  It may be
           specified in the same ways as the dots operand of the char
           directive.

     include file # comment
        Use the include directive to include the content of a text
        subtable.  It is recursive, which means that any text subtable
        can itself include yet another text subtable.  Care must be
        taken to ensure that an "include loop" is not created.


        file
           The file to be included.  It may be either a relative or an
           absolute path.  If relative, it is anchored at the directory
           containing the including file.

  6.2.  Attributes Tables

  Files with names of the form *.atb are attributes tables, and with
  names of the form *.ati are attributes subtables.  They are used when
  BRLTTY is displaying screen attributes rather than screen content (see
  the ``DISPMD'' command).  Each of the eight braille dots represents
  one of the eight VGA attribute bits.

  The following attributes tables are provided:

     left_right
        The lefthand column represents the foreground colours:

        Dot 1
           Blue

        Dot 2
           Green

        Dot 3
           Red

        Dot 7
           Bright

        The righthand column represents the background colours:

        Dot 4
           Blue

        Dot 5
           Green

        Dot 6
           Red

        Dot 8
           Blink

        A dot is raised when its corresponding attribute bit is on.
        This is the default attributes table because it's the most intu-
        itive.  One of its problems, though, is that it's difficult to
        discern the difference between normal (white on black) and re-
        verse (black on white) video.

     invleft_right
        The lefthand column represents the foreground colours:

        Dot 1
           Blue

        Dot 2
           Green

        Dot 3
           Red

        Dot 7
           Bright

        The righthand column represents the background colours:

        Dot 4
           Blue

        Dot 5
           Green

        Dot 6
           Red

        Dot 8
           Blink

        A background bit being on triggers its corresponding dot,
        whereas a foreground bit being off triggers its corresponding
        dot.  This unintuitive logic actually makes it easier to read
        the most commonly used attribute combinations.

     upper_lower
        The upper square represents the foreground colours:

        Dot 1
           Red

        Dot 4
           Green

        Dot 2
           Blue

        Dot 5
           Bright

        The lower square represents the background colours:

        Dot 3
           Red

        Dot 6
           Green

        Dot 7
           Blue

        Dot 8
           Blink

        A dot is raised when its corresponding attribute bit is on.

  See the ``-a'' command line option, the ``attributes-table'' configu-
  ration file directive, and the ``--with-attributes-table'' build op-
  tion for details regarding how to use an alternate attributes table.

  6.2.1.  Attributes Table Format

  An attributes table consists of a sequence of directives, one per
  line, which define how combinations of VGA attributes are to be
  represented in braille.  UTF-8 character encoding must be used.
  White-space (blanks, tabs) at the beginning of a line, as well as
  before and/or after any operand of any directive, is ignored.  Lines
  containing only white-space are ignored.  If the first non-white-space
  character of a line is "#" then that line is a comment and is ignored.

  6.2.2.  Attributes Table Directives

  The following directives are provided:

     dot dot state # comment
        Use the dot directive to specify what a specific dot represents.


        dot
           The dot being defined.  It is a single digit within the range
           1-8 as defined by the ``Standard Braille Dot Numbering
           Convention''.

        state
           What the dot represents.  It may be:

           =attribute
              The dot is raised if the named attribute is on.

           ~attribute
              The dot is raised if the named attribute is off.

           The names of the attribute bits are:

           0X01
              fg-blue

           0X02
              fg-green

           0X04
              fg-red

           0X08
              fg-bright

           0X10
              bg-blue

           0X20
              bg-green

           0X40
              bg-red

           0X80
              blink

        Examples:

        ·  dot 1 =fg-red

        ·  dot 2 ~bg-blue

     include file # comment
        Use the include directive to include the content of an
        attributes subtable.  It is recursive, which means that any
        attributes subtable can itself include yet another attributes
        subtable.  Care must be taken to ensure that an "include loop"
        is not created.


        file
           The file to be included.  It may be either a relative or an
           absolute path.  If relative, it is anchored at the directory
           containing the including file.

  6.3.  Contraction Tables

  Files with names of the form *.ctb are contraction tables, and with
  names of the form *.cti are contraction subtables.  They are used by
  BRLTTY to translate character sequences on the screen into their
  corresponding contracted braille representations.

  BRLTTY presents contracted braille if:

  ·  A contraction table has been selected.  See the ``-c'' command line
     option and the ``contraction-table'' configuration file directive
     for details.

  ·  The 6-dot braille feature has been activated.  See the ``SIXDOTS''
     command and the ``Text Style'' preference for details.

     This feature isn't available if the ``--disable-contracted-
     braille'' build option was specified.

  The following contraction tables are provided:

          Name        Language
          auto        locale-based autoselection
          af          Afrikaans (contracted)
          am          Amharic (uncontracted)
          de          German
          de-g0       German (uncontracted)
          de-g1       German (basic contractions)
          de-g2       German (contracted)
          de-1998     German (contracted - 1998 standard)
          de-2015     German (contracted - 2015 standard)
          en          English
          en_US       English (United States)
          en-ueb-g1   English (Unified English Braille, grade 1)
          en-ueb-g2   English (Unified English Braille, grade 2)
          en-us-g2    English (US, grade 2)
          es          Spanish (grade 2)
          fr          French
          fr-g1       French (uncontracted)
          fr-g2       French (contracted)
          ha          Hausa (contracted)
          id          Indonesian (contracted)
          ipa         International Phonetic Alphabet
          ja          Japanese (uncontracted)
          ko          Korean
          ko-g0       Korean (uncontracted)
          ko-g1       Korean (grade 1)
          ko-g2       Korean (grade 2)
          lt          Lituanian
          mg          Malagasy (contracted)
          mun         Munda (contracted)
          nl          Dutch (contracted)
          ny          Chichewa (contracted)
          pt          Portuguese (grade 2)
          ru          Russian (grade 1)
          si          Sinhalese (uncontracted)
          sw          Swahili (contracted)
          th          Thai (contracted)
          zh_TW       Chinese (Taiwan, uncontracted)
          zu          Zulu (contracted)


  See the ``-c'' command line option, and the ``contraction-table''
  configuration file directive for details regarding how to use a
  contraction table.

  6.3.1.  Contraction Table Format

  A contraction table consists of a sequence of entries, one per line,
  which define how character sequences are to be represented in braille.
  UTF-8 character encoding must be used.  White-space (blanks, tabs) at
  the beginning of a line, as well as before and/or after any operand,
  is ignored.  Lines containing only white-space are ignored.  If the
  first non-white-space character of a line is "#" then that line is a
  comment and is ignored.

  The format of a contraction table entry is:

       directive operand ... [comment]


  Each directive has a specific number of operands.  Any text beyond the
  last operand of a directive is interpreted as a comment.  The order of
  the entries within a contraction table is, in general, anything that
  is convenient for its maintainer(s).  An entry which defines an en-
  tity, e.g. class, must precede all references to that entity.

  Entries which match character sequences are automatically rearranged
  from longest to shortest so that longer matches are always preferred.
  If more than one entry matches the same character sequence then their
  original table ordering is maintained.  Thus, the same sequence may be
  translated differently under different circumstances.

  6.3.2.  Contraction Table Operands


     characters
        The first operand of a character sequence matching directive is
        the character sequence to be matched.  Each character within the
        sequence may be:

        ·  Any single character other than a backslash or a white-space
           character.

        ·  A backslash-prefixed special character.  These are:

              -

           \b The backspace character.  -

           \f The formfeed character.  -

           \n The newline character.  -

           \o###
              The three-digit octal representation of a character.  -

           \r The carriage return character.  -

           \s The space character.  -

           \t The horizontal tab character.  -

           \u####
              The four-digit hexadecimal representation of a character.
              -

           \U########
              The eight-digit hexadecimal representation of a character.
              -

           \v The vertical tab character.  -

           \x##
              The two-digit hexadecimal representation of a character.
              -

           \X##
              ... (the case of the X and of the digits isn't
              significant) -

           \# A literal number sign.  -

           \<name>
              The Unicode name of a character (use _ for space).  -

           \\ A literal backslash.

     representation
        The second operand of those character sequence matching
        directives which have one is the braille representation of the
        sequence.  Each braille cell is specified as a sequence of one
        to eight dot numbers.  A dot number is a digit within the range
        1-8 as defined by the ``Standard Braille Dot Numbering
        Convention''.  The special dot number 0, which may not be used
        in conjunction with any other dot number, means no dots.

  6.3.3.  Opcodes

  An opcode is a keyword which tells the translator how to interpret the
  operands.  The opcodes are grouped here by function.

  6.3.3.1.  Table Administration

  These opcodes make it easier to write contraction tables.  They have
  no direct effect on the character translation.

     include path
        Include the contents of another file.  Nesting can be to any
        depth.  Relative paths are anchored at the directory of the
        including file.

     locale locale
        Define the locale for character interpretation (lowercase,
        uppercase, numeric, etc.).  The locale may be specified as:

        language[_country][.charset][@modifier]
           The language component is required and should be a two-letter
           ISO-639 language code.  The country component is optional and
           should be a two-letter ISO-3166 country code.  The charset
           component is optional and should be a character set name,
           e.g. ISO-8859-1.

        C  7-bit ASCII.

        -  No locale.

        The last locale specification applies to the entire table.  If
        this opcode isn't used then the C locale is assumed.

  6.3.3.2.  Special Symbol Definition

  These opcodes define special symbols which must be inserted into the
  braille text in order to clarify it.

     capsign dots
        The symbol which capitalizes a single letter.

     begcaps dots
        The symbol which begins a block of capital letters within a
        word.

     endcaps dots
        The symbol which ends a block of capital letters within a word.

     letsign dots
        The symbol which marks a letter which isn't part of a word.

     numsign dots
        The symbol which marks the beginning of a number.

  6.3.3.3.  Character Translation

  These opcodes define the braille representations for character
  sequences.  Each of them defines an entry within the contraction
  table.  These entries may be defined in any order except, as noted
  below, when they define alternate representations for the same
  character sequence.

  Each of these opcodes has a characters operand (which must be
  specified as a string), and a built-in condition governing its
  eligibility for use.  The text is processed strictly from left to
  right, character by character, with the most eligible entry for each
  position being used.  If there's more than one eligible entry for a
  given position, then the one with the longest character string is
  used.  If there's more than one eligible entry for the same character
  string, then the one defined nearest to the beginning of the table is
  used (this is the only order dependency).

  Many of these opcodes have a dots operand which defines the braille
  representation for its characters operand.  It may also be specified
  as an equals sign (=), in which case it means one of two things.  If
  the entry is for a single character, then it means that the currently
  selected computer braille representation (see the ``-t'' command line
  option and the ``text-table'' configuration file directive) for that
  character is to be used.  If it's for a multi-character sequence, then
  the default representation for each character (see ``always'') within
  the sequence is to be used.

  Some special terms are used within the descriptions of these opcodes.

     word
        A maximal sequence of one or more consecutive letters.

  Now, finally, here are the opcode descriptions themselves:

     literal characters
        Translate the entire white-space-bounded containing character
        sequence into computer braille (see the ``-t'' command line
        option and the ``text-table'' configuration file directive).

     replace characters characters
        Replace the first set of characters, no matter where they
        appear, with the second.  The replaced characters aren't
        reprocessed.

     always characters dots
        Translate the characters no matter where they appear.  If
        there's only one character, then, in addition, define the
        default representation for that character.

     repeatable characters dots
        Translate the characters no matter where they appear.  Ignore
        any consecutive repetitions of the same sequence.

     largesign characters dots
        Translate the characters no matter where they appear.  Remove
        white-space between consecutive words matched by this opcode.

     lastlargesign characters dots
        Translate the characters no matter where they appear.  Remove
        preceding white-space if the previous word was matched by the
        ``largesign'' opcode.

     word characters dots
        Translate the characters if they're a word.

     joinword characters dots
        Translate the characters if they're a word.  Remove the
        following white-space if the first character after it is a
        letter.

     lowword characters dots
        Translate the characters if they're a white-space-bounded word.

     contraction characters
        Prefix the characters with a letter sign (see ``letsign'') if
        they're a word.

     sufword characters dots
        Translate the characters if they're either a word or at the
        beginning of a word.

     prfword characters dots
        Translate the characters if they're either a word or at the end
        of a word.

     begword characters dots
        Translate the characters if they're at the beginning of a word.

     begmidword characters dots
        Translate the characters if they're either at the beginning or
        in the middle of a word.

     midword characters dots
        Translate the characters if they're in the middle of a word.

     midendword characters dots
        Translate the characters if they're either in the middle or at
        the end of a word.

     endword characters dots
        Translate the characters if they're at the end of a word.

     prepunc characters dots
        Translate the characters if they're part of punctuation at the
        beginning of a word.

     postpunc characters dots
        Translate the characters if they're part of punctuation at the
        end of a word.

     begnum characters dots
        Translate the characters if they're at the beginning of a
        number.

     midnum characters dots
        Translate the characters if they're in the middle of a number.

     endnum characters dots
        Translate the characters if they're at the end of a number.

  6.3.3.4.  Character Classes

  These opcodes define and use character classes.  A character class
  associates a set of characters with a name.  The name then refers to
  any character within the class.  A character may belong to more than
  one class.

  The following character classes are automatically predefined based on
  the selected locale:

     digit
        Numeric characters.

     letter
        Both uppercase and lowercase alphabetic characters.  Some
        locales have additional letters which are neither uppercase nor
        lowercase.

     lowercase
        Lowercase alphabetic characters.

     punctuation
        Printable characters which are neither white-space nor
        alphanumeric.

     space
        White-space characters.  In the default locale these are: space,
        horizontal tab, vertical tab, carriage return, new line, form
        feed.

     uppercase
        Uppercase alphabetic characters.

  The opcodes which define and use character classes are:

     class name characters
        Define a new character class.  The characters operand must be
        specified as a string.  A character class may not be used until
        it's been defined.

     after class opcode ...
        The specified opcode is further constrained in that the matched
        character sequence must be immediately preceded by a character
        belonging to the specified class.  If this opcode is used more
        than once on the same line then the union of the characters in
        all the classes is used.

     before class opcode ...
        The specified opcode is further constrained in that the matched
        character sequence must be immediately followed by a character
        belonging to the specified class.  If this opcode is used more
        than once on the same line then the union of the characters in
        all the classes is used.

  6.4.  Key Tables

  Files with names of the form *.ktb are key tables, and with names of
  the form *.kti are key subtables.  They are used by BRLTTY to bind
  braille display and keyboard key combinations to BRLTTY commands.

  The names of braille display key table files begin with brl-xx-",
  where xx is the two-letter ``driver identification code''.  The rest
  of the name identifies the model(s) for which the key table is used.

  The names of keyboard table files begin with kbd-.  The rest of the
  name describes the kind of keyboard for which the keyboard table has
  been designed.

  The following keyboard tables are provided:

     braille
        bindings for braille keyboards

     desktop
        bindings for full keyboards

     keypad
        bindings for keypad-based navigation

     laptop
        bindings for keyboards without a keypad

     sun_type6
        bindings for Sun Type 6 keyboards

  See the ``-k'' command line option, and the ``keyboard-table'' config-
  uration file directive for details regarding how to select a keyboard
  table.

  6.4.1.  Key Table Directives

  A key table consists of a sequence of directives, one per line, which
  define how keys and key combinations are to be interpreted.  UTF-8
  character encoding must be used.  White-space (blanks, tabs) at the
  beginning of a line, as well as before and/or after any operand, is
  ignored.  Lines containing only white-space are ignored.  If the first
  non-white-space character of a line is a number (#) sign then that
  line is a comment and is ignored.

  The precedence for resolving each key press/release event is as
  follows:

  1. A hotkey press or release defined within the current context.  See
     the ``hotkey'' directive for details.

  2. A key combination defined within the current context.  See the
     ``bind'' directive for details.

  3. A braille keyboard command defined within the current context.  See
     the ``map'' and ``superimpose'' directives for details.

  4. A key combination defined within the default context.  See the
     ``bind'' directive for details.

  The following directives are provided:

  6.4.1.1.  The Assign Directive

  Create or update a variable associated with the current include level.
  The variable is visible to the current and to lower include levels,
  but not to higher include levels.

  assign variable [value]

     variable
        The name of the variable.  If the variable doesn't already exist
        at the current include level then it is created.

     value
        The value which is to be assigned to the variable.  If it's not
        supplied then a zero-length (null) value is assigned.

  The escape sequence \{variable} is substituted with the value of the
  variable named within the braces.  The variable must have been defined
  at the current or at a higher include level.

  Examples:

  ·  assign nullValue

  ·  assign ReturnKey Key1

  ·  bind \{ReturnKey} RETURN

  6.4.1.2.  The Bind Directive

  Define which BRLTTY command is executed when a particular combination
  of one or more keys is pressed.  The binding is defined within the
  current context.

  bind keys command

     keys
        The key combination which is to be bound.  It's a sequence of
        one or more key names separated by plus (+) signs.  The final
        (or only) key name may be optionally prefixed with an
        exclamation (!) point.  The keys may be pressed in any order,
        with the exception that if the final key name is prefixed with
        an exclamation point then it must be pressed last.  The
        exclamation point prefix means that the command is executed as
        soon as that key is pressed.  If not used, the command is
        executed as soon as any of the keys is released.

     command
        The name of a BRLTTY command.  One or more modifiers may be
        optionally appended to the command name by using a plus (+) sign
        as the separator.

        ·  For commands which enable/disable a feature:

           ·  If the modifier +on is specified then the feature is
              enabled.

           ·  If the modifier +off is specified then the feature is
              disabled.

           ·  If neither +on nor +off is specified then the state of the
              feature is toggled on/off.

        ·  For commands which move the braille window:

           ·  If the modifier +route is specified then, if necessary,
              the cursor is automatically routed so that it's always
              visible on the braille display.

        ·  For commands which move the braille window to a specific line
           on the screen:

           ·  If the modifier +toleft is specified then the braille
              window is also moved to the beginning of that line.

           ·  If the modifier +scaled is specified then the set of keys
              bound to the command is interpreted as though it were a
              scroll bar.  If it isn't, then there's a one-to-one
              correspondence between keys and lines.

        ·  For commands which require an offset:

           ·  The modifier +offset, where offset is a non-negative
              integer, may be specified.  If it isn't supplied then +0
              is assumed.

  Examples:

  ·  bind Key1 CSRTRK

  ·  bind Key1+Key2 CSRTRK+off

  ·  bind Key1+Key3 CSRTRK+on

  ·  bind Key4 TOP

  ·  bind Key5 TOP+route

  ·  bind VerticalSensor GOTOLINE+toleft+scaled

  ·  bind Key6 CONTEXT+1

  6.4.1.3.  The Context Directive

  Define alternate ways to interpret certain key events and/or
  combinations.  A context contains definitions created by the ``bind'',
  ``hotkey'', ``ignore'', ``map'', and ``superimpose'' directives.

  context name [title]

     name
        Which context subsequent definitions are to be created within.
        These special contexts are predefined:

        default
           The default context.  If a key combination hasn't been
           defined within the current context then its definition within
           the default context is used.  This only applies to
           definitions created by the ``bind'' directive.

        menu
           This context is used when within BRLTTY's preferences menu.

     title
        A person-readable description of the context.  It may contain
        spaces, and standard capitalization conventions should be used.
        This operand is optional.  If supplied when selecting a context
        which already has a title then the two must match.  Special
        contexts already have internally-assigned titles.

  A context is created the first time it's selected.  It may be
  reselected any number of times thereafter.

  All subsequent definitions until either the next ``context'' directive
  or the end of the current include level are created within the
  selected context.  The initial context of the top-level key table is
  default.  The initial context of an included key subtable is the
  context which was selected when it was included.  Context changes
  within included key subtables don't affect the context of the
  including key table or subtable.

  If a context has a title then it is persistent.  When a key event
  causes a persistent context to be activated, that context remains
  current until a subsequent key event causes a different persistent
  context to be activated.

  If a context doesn't have a title then it is temporary.  When a key
  event causes a temporary context to be activated, that context is only
  used to interpret the very next key event.

  Examples:

  ·  context menu

  ·  context braille Braille Input

  ·  context DESCCHAR

  6.4.1.4.  The Hide Directive

  Specify whether or not certain definitions (see the ``bind'',
  ``hotkey'', ``map'', and ``superimpose'' directives) and notes (see
  the ``note'' directive) are included within the key table's help text.

  hide state

     state
        One of these keywords:

        on They're excluded.

        off
           They're included.

  The specified state applies to all subsequent definitions and notes
  until either the next hide directive or the end of the current include
  level.  The initial state of the top-level key table is off.  The
  initial state of an included key subtable is the state which was
  selected when it was included.  State changes within included key
  subtables don't affect the state of the including key table or
  subtable.

  Examples:

  ·  hide on

  6.4.1.5.  The Hotkey Directive

  Bind the press and release events of a specific key to two separate
  BRLTTY commands.  The bindings are defined within the current context.

  hotkey key press release

     key
        The name of the key which is to be bound.

     press
        The name of the BRLTTY command which is to be executed whenever
        the key is pressed.

     release
        The name of the BRLTTY command which is to be executed whenever
        the key is released.

  Modifiers may be appended to the command names.  See the command
  operand of the ``bind'' directive for details.

  Specify NOOP if no command is to be executed.  Specifying NOOP for
  both commands effectively disables the key.

  Examples:

  ·  hotkey Key1 CSRVIS+off CSRVIS+on

  ·  hotkey Key2 NOOP NOOP

  6.4.1.6.  The IfKey Directive

  Conditionally process a key table directive only if the device has a
  particular key.

  ifkey key directive

     key
        The name of the key whose availability is to be tested.

     directive
        The key table directive which is to be conditionally processed.

  Examples:

  ·  ifkey Key1 ifkey Key2 bind Key1+Key2 HOME

  6.4.1.7.  The Include Directive

  Process the directives within a key subtable.  It's recursive, which
  means that any key subtable can itself include yet another key
  subtable.  Care must be taken to ensure that an "include loop" is not
  created.

  include file

     file
        The key subtable which is to be included.  It may be either a
        relative or an absolute path.  If relative, it's anchored at the
        directory containing the including key table or subtable.

  Examples:

  ·  include common.kti

  ·  include /path/to/my/keys.kti

  6.4.1.8.  The Ignore Directive

  Ignore a specific key while within the current context.

  ignore key

     key
        The name of the key which is to be ignored.

  Examples:

  ·  ignore Key1

  6.4.1.9.  The Map Directive

  Map a key to a braille keyboard function.  The mapping is defined
  within the current context.

  map key function

     key
        The name of the key which is to be mapped.  More than one key
        may be mapped to the same braille keyboard function.

     function
        The name of the braille keyboard function.  It may be one of the
        following keywords:

        DOT1
           The upper-left standard braille dot.

        DOT2
           The middle-left standard braille dot.

        DOT3
           The lower-left standard braille dot.

        DOT4
           The upper-right standard braille dot.

        DOT5
           The middle-right standard braille dot.

        DOT6
           The lower-right standard braille dot.

        DOT7
           The lower-left computer braille dot.

        DOT8
           The lower-right computer braille dot.

        SPACE
           The space bar.

        SHIFT
           The shift key.

        UPPER
           If a lowercase letter is being entered then translate it to
           its uppercase equivalent.

        CONTROL
           The control key.

        META
           The left alt key.

  If a key combination consists only of keys which have been mapped to
  braille keyboard functions, and if those functions when combined form
  a valid braille keyboard command, then that command is executed as
  soon as any of the keys is released.  A valid braille keyboard command
  must include either any combination of dot keys or the space bar (but
  not both).  If at least one dot key is included then the braille
  keyboard functions specified by the ``superimpose'' directives within
  the same context are also implicitly included.

  Examples:

  ·  map Key1 DOT1

  6.4.1.10.  The Note Directive

  Add a person-readable explanation to the key table's help text.  Notes
  are commonly used, for example, to describe the placement, sizes, and
  shapes of the keys on the device.

  note text

     text
        The explanation which is to be added.  It may contain spaces,
        and should be grammatically correct.

  Each note specifies exactly one line of explanatory text.  Leading
  space is ignored so indentation cannot be specified.

  There's no limit to the number of notes which may be specified.  All
  of them are gathered together and presented in a single block at the
  start of the key table's help text.

  Examples:

  ·  note Key1 is the round key at the far left on the front surface.

  6.4.1.11.  The Superimpose Directive

  Implicitly include a braille keyboard function whenever a braille
  keyboard command consisting of at least one dot is executed.  The
  implicit inclusion is defined within the current context.  Any number
  of them may be specified.

  superimpose function

     function
        The name of the braille keyboard function.  See the function
        operand of the ``map'' directive for details.

  Examples:

  ·  superimpose DOT7

  6.4.1.12.  The Title Directive

  Provide a person-readable summary of the key table's purpose.

  title text

     text
        A one-line summary of what the key table is used for.  It may
        contain spaces, and standard capitalization conventions should
        be used.

  The title of the key table may be specified only once.

  Examples:

  ·  title Bindings for Keypad-based Navigation

  6.4.2.  Keyboard Properties

  The default is that all keyboards are monitored.  A subset of the
  keyboards may be selected by specifying one or more of the following
  properties (see the ``-K'' command line option, and the ``keyboard-
  properties'' configuration file directive):

     type
        The bus type, specified as one of the following keywords: any,
        ps2, usb, bluetooth.

     vendor
        The vendor identifier, specified as a 16-bit unsigned integer.

     product
        The product identifier, specified as a 16-bit unsigned integer.

  The vendor and product identifiers may be specified in decimal (no
  prefix), octal (prefixed by 0), or hexadecimal (prefixed by 0x).
  Specifying 0 means match any value (as if the property weren't
  specified).

  7.  Advanced Topics

  7.1.  Installing Multiple Versions

  It's easy to have more than one version of BRLTTY installed on the
  same system at the same time.  This capability allows you to test a
  new version before removing the old one.

  The ``--with-execute-root'' build option allows you to install the
  complete ``installed file hierarchy'' anywhere you want such that it's
  entirely self-contained.  Remembering that it's best to keep all of
  BRLTTY's components within the root file system, you can build it like
  this:


       ./configure --with-execute-root=/brltty-3.1
       make install

  You can then run it like this:

       /brltty-3.1/bin/brltty


  When version 3.2 is released, just install it in a different location
  and run the new executable from there.


       ./configure --with-execute-root=/brltty-3.2
       make install
       /brltty-3.2/bin/brltty

  So far, this paradigm is somewhat awkward for at least two reasons.
  One is that these long path names are too hard to type, and the other
  is that you don't want to fiddle with your system's boot sequence each
  time you want to switch to a different version of BRLTTY.  These
  problems are easily solved by adding a symbolic link for the
  executable.

       ln -s /brltty-3.1/bin/brltty /bin/brltty


  When it's time to switch to the newer version, just repoint the sym-
  bolic link.

       ln -s /brltty-3.2/bin/brltty /bin/brltty


  If you'd like to get really fancy, then introduce another level of
  indirection in order to make all of BRLTTY's files for any given
  version look like they're in all of the standard places.  First,
  create a symbolic link through a common repointable location from each
  of BRLTTY's standard locations.


       ln -s /brltty/bin/brltty /bin/brltty
       ln -s /brltty/etc/brltty /etc/brltty
       ln -s /brltty/lib/brltty /lib/brltty

  Then all you need to do is to point /brltty to the desired version.

       ln -s /brltty-3.1 /brltty


  7.2.  Installation/Rescue Root Disks for Linux

  BRLTTY can run as a stand-alone executable.  Everything it needs to
  know can be explicitly configured at build-time (see ``Build
  Options'').  If the data directory (see the ``--with-data-directory''
  and ``--with-execute-root'' build options) doesn't exist, then BRLTTY
  looks in /etc for the files it needs.  Even if any of these files
  don't exist at all, BRLTTY still works!

  If, for some reason, you ever create the data directory (usually
  /etc/brltty) by hand, it's important to set its permissions so that
  only root can create files within it.

       chmod 755 /etc/brltty


  The screen content inspection device (usually /dev/vcsa) is required.
  It should already exist unless your Linux distribution is quite old.
  If necessary, you can create it with:


       mknod /dev/vcsa c 7 128
       chmod 660 /dev/vcsa
       chown root.tty /dev/vcsa

  One problem often encountered when trying to use BRLTTY in an
  uncertain environment like a root disk or an incomplete system is that
  it might not find the shared libraries (or parts thereof) which it
  needs.  Root disks often use subset and/or outdated versions of the
  libraries which may be inadequate.  The solution is to configure
  BRLTTY with the ``--enable-standalone-programs'' build option.  This
  removes all dependencies on shared libraries, but, unfortunately, also
  creates a larger executable.  There are a number of build options
  which can be used to selectively remove unneeded features from BRLTTY
  in order to somewhat mitigate this problem (see section ``Build
  Features'').

  The executable is stripped during the ``make install''.  This
  significantly reduces its size by removing its symbol table.  You'll
  get a much smaller executable, therefore, if you complete the full
  build procedure, and then copy it from its installed location.  If,
  however, you copy it from the build directory, it'll be way too big.
  Don't forget to strip it.

       strip brltty


  7.3.  Future Enhancements

  Apart from fixing bugs and supporting more types of braille displays,
  we hope, time permitting, to work on the following:

     Better Attribute Handling

        ·  Attribute tracking.

        ·  Mixed text and attribute mode.

     Scroll Tracking
        Locking the braille window to one line as it scrolls on the
        screen.

     Better Speech Support

        ·  Mixed braille and speech for faster reading of text.

        ·  Better speech navigation.

        ·  More speech synthesizers.

     Screen Subregions
        Ignore cursor motion outside the region, and set soft
        navigational boundaries at the edges of the region.

  See the file TODO for a more complete list.

  7.4.  Known Bugs

  At the time of writing (December 2001), the following problems are
  known:

  Cursor routing is implemented as a looping sub-process which runs at
  reduced priority to avoid using too much cpu time.  Different system
  loads require different settings of its parameters.  The defaults work
  very well in a typical Unix editor on a fairly lightly loaded system,
  but very poorly in some other situations, e.g. over a slow serial link
  to a remote host.


  A.  Supported Braille Displays

  BRLTTY supports the following braille displays:

       Name                Models
       _________________________________________________________________
       Albatross           46/80
       Alva                ABT (3nn)
                           Delphi (4nn)
                           Satellite (5nn)
                           Braille System 40
                           Braille Controller 640/680
                           Easy Link 12
       Baum                BrailleConnect 12/24/32/40/64/80
                           Brailliant 24/32/40/64/80
                           Conny 12
                           DM80 Plus
                           EcoVario 24/32/40/64/80
                           Inka
                           NLS eReader Zoomax
                           Orbit Reader 20/40
                           PocketVario 24
                           Pronto! V3 18/40
                           Pronto! V4 18/40
                           RBT 40/80
                           Refreshabraille 18
                           SuperVario 32/40/64/80
                           Vario 40/80
                           VarioConnect 12/24/32/40/64/80
                           VarioPro 40/64/80
                           VarioUltra 20/32/40
       BrailComm           III
       BrailleLite         18/40/M20/M40
       BrailleMemo         Pocket
                           Smart
                           Next Touch
       BrailleNote         18/32
                           Apex
       Braudi
       BrlAPI
       Canute              360 (40x9)
       Cebra               20/40/60/80/100/120/140
       CombiBraille        25/45/85
       DotPad
       EcoBraille          20/40/80
       EuroBraille         AzerBraille
                           Clio
                           Esys
                           Iris
                           NoteBraille
                           Scriba
       FrankAudiodata      B2K84
       FreedomScientific   Focus 1 44/70/84
                           Focus 2 40/80
                           Focus Blue 14/40/80
                           PAC Mate 20/40
       HandyTech           Modular 20/40/80
                           Modular Evolution 64/88
                           Modular Connect 88
                           Active Braille
                           Active Braille S
                           Active Star 40
                           Actilino
                           Activator
                           Activator Pro 64/80
                           Basic Braille 16/20/32/40/48/64/80
                           Basic Braille Plus 20/32/40/48/64/80/84
                           Braille Wave
                           Braillino
                           Easy Braille
                           Braille Star 40/80
                           Connect Braille 40
                           Bookworm
       Hedo                ProfiLine
                           MobilLine
       HIMS                Braille Sense
                           BrailleSense 6
                           SyncBraille
                           Braille Edge
                           Smart Beetle
                           QBrailleXL
                           eMotion
       HumanWare           Brailliant BI 14/32/40
                           Brailliant BI 20X/40X
                           Brailliant B 80
                           BrailleNote Touch
                           BrailleOne
                           APH Chameleon 20
                           APH Mantis Q40
                           NLS eReader
       Inceptor            BrailleMe (20)
       Iris
       Libbraille
       LogText             32
       MDV                 MB208
                           MB248
                           MB408L
                           MB408L+
                           Lilli Blu
       Metec               BD-40
       MiniBraille         20
       MultiBraille        MB125CR
                           MB145CR
                           MB185CR
       NinePoint           8
       Papenmeier          Compact 486
                           Compact/Tiny
                           IB 80 CR Soft
                           2D Lite (plus)
                           2D Screen Soft
                           EL 80
                           EL 2D 40/66/80
                           EL 40/66/70/80 S
                           EL 40/60/80 C
                           EL 2D 80 S
                           EL 40 P
                           EL 80 II
                           Elba 20/32
                           Trio 40/Elba20/Elba32
                           Live 20/40
       Pegasus             20/27/40/80
       Seika               3/4/5 (40)
                           80
                           Mini (16)
       TechniBraille
       TSI                 Navigator 20/40/80
                           PowerBraille 40/65/80
       VideoBraille        40
       VisioBraille        20/40
       Voyager             44/70
                           Part232 (serial adapter)
                           BraillePen/EasyLink


  B.  Supported Speech Synthesizers

  BRLTTY supports the following speech synthesizers:

           Name             Models
           _____________________________________________________________
           Alva             Delphi (4nn)
           Android          text to speech engine
           BrailleLite
           CombiBraille
           eSpeak           text to speech engine
           eSpeak-NG        text to speech engine
           ExternalSpeech   runs /usr/local/bin/externalspeech
           Festival         text to speech engine
           FestivalLite     text to speech engine
           GenericSay       pipes to /usr/local/bin/say
           Mikropuhe        text to speech engine
           Swift            text to speech engine
           Theta            text to speech engine
           ViaVoice         text to speech engine


  C.  Driver Identification Codes


                    Code   Name
                    ____________________________________________________
                    al     Alva
                    an     Android
                    at     Albatross
                    ba     BrlAPI
                    bc     BrailComm
                    bd     Braudi
                    bg     B2G
                    bl     BrailleLite
                    bm     Baum (Native, HT, PB1, PB2)
                    bn     BrailleNote
                    cb     CombiBraille
                    ce     Cebra
                    cn     Canute
                    dp     DotPad
                    ec     EcoBraille
                    en     eSpeak-NG
                    es     eSpeak
                    eu     EuroBraille
                    fa     FrankAudiodata
                    fl     FestivalLite
                    fs     FreedomScientific
                    fv     Festival
                    gs     GenericSay
                    hd     Hedo
                    hm     HIMS
                    ht     HandyTech
                    hw     HumanWare
                    ic     Inceptor
                    ir     Iris
                    lb     Libbraille
                    lt     LogText
                    mb     MultiBraille
                    md     MDV
                    mm     BrailleMemo
                    mn     MiniBraille
                    mp     Mikropuhe
                    mt     Metec
                    no     no driver
                    np     NinePoint
                    pg     Pegasus
                    pm     Papenmeier
                    sd     SpeechDispatcher
                    sk     Seika
                    sw     Swift
                    th     Theta
                    tn     TechniBraille
                    ts     Telesensory Systems Inc.
                    tt     TTY
                    vd     VideoBraille
                    vo     Voyager
                    vr     Virtual
                    vs     VisioBraille
                    vv     ViaVoice
                    xs     ExternalSpeech
                    xw     XWindow


  D.  Supported Screen Drivers

  BRLTTY supports the following screen drivers:

     as AT-SPI

     hd This driver provides direct access to the Hurd console screen.
        It's only selectable, and is the default, on Hurd systems.

     lx This driver provides direct access to the Linux console screen.
        It's only selectable, and is the default, on Linux systems.

     sc This driver provides access to the screen program.  It's
        selectable on all systems, and is the default if no native
        screen driver is available.  The patch for screen which we
        provide (see the Patches subdirectory) must be applied.  Use of
        this driver, due to the fact that screen must be concurrently
        running, makes BRLTTY effectively useful only after the user has
        logged in.

     wn This driver provides direct access to the Windows console
        screen.  It's only selectable, and is the default, on
        Windows/Cygwin systems.

  E.  Operand Syntax

  E.1.  Driver Specification

  A braille display or speech synthesizer driver must be specified via
  its two-letter ``driver identification code''.

  A comma-delimited list of drivers may be specified.  If this is done
  then autodetection is performed using each listed driver in sequence.
  You may need to experiment in order to determine the most reliable
  order since some drivers autodetect better than others.

  If the single word auto is specified then autodetection is performed
  using only those drivers which are known to be reliable for this
  purpose.

  E.2.  Braille Device Specification

  The general form of a braille device specification (see the ``-d''
  command line option, the ``braille-device'' configuration file
  directive, and the ``--with-braille-device'' build option) is
  qualifier:data.  For backward compatibility with earlier releases, if
  the qualifier is omitted then serial: is assumed.

  The following device types are supported:

     Bluetooth
        For a bluetooth device, specify bluetooth:address.  The address
        must be six two-digit hexadecimal numbers separated by colons,
        e.g. 01:23:45:67:89:AB.

     Serial
        For a serial device, specify serial:/path/to/device.  The
        serial: qualifier is optional (for backward compatibility).  If
        a relative path is given then it's anchored at /dev (the usual
        location where devices are defined on a Unix-like system).  The
        following device specifications all refer to the first serial
        device on Linux:

        ·  serial:/dev/ttyS0

        ·  serial:ttyS0

        ·  /dev/ttyS0

        ·  ttyS0

     USB
        For a USB device, specify usb:.  BRLTTY will search for the
        first USB device which matches the braille display driver being
        used.  If this is inadequate, e.g. if you have more than one USB
        braille display which requires the same driver, then you can
        refine the device specification by appending the serial number
        of the display to it, e.g. usb:12345.  N.B.: The "identification
        by serial number" feature doesn't work for some models because
        some manufacturers either don't set the USB serial number
        descriptor at all or do set it but not to a unique value.

  A comma-delimited list of braille devices may be specified.  If this
  is done then autodetection is performed on each listed device in
  sequence.  This feature is particularly useful if you have a braille
  display with more than one interface, e.g. both a serial and a USB
  port.  In this case it's usually better to list the USB port first,
  e.g. usb:,serial:/dev/ttyS0, since the former tends to autodetect more
  reliably than the latter.

  E.3.  PCM Device Specification

  In most cases the PCM device is the full path to an appropriate system
  device.  Exceptions are:

     ALSA
        The name of and arguments for the physical or logical device,
        i.e. name[:argument,...].

  The default PCM device is:

                 Platform     Device
                 _______________________________________________________
                 FreeBSD      /dev/dsp
                 Linux/ALSA   hw:0,0
                 Linux/OSS    /dev/dsp
                 NetBSD       /dev/audio
                 OpenBSD      /dev/audio
                 Qnx          preferred PCM output device
                 Solaris      /dev/audio


  E.4.  MIDI Device Specification

  In most cases the MIDI device is the full path to an appropriate
  system device.  Exceptions are:

     ALSA
        The client and port separated by a colon, i.e. client:port.
        Each may be specified either as a number or as a case-sensitive
        substring of its name.

  The default MIDI device is:

            Platform     Device
            ____________________________________________________________
            Linux/ALSA   the first available MIDI output port
            Linux/OSS    /dev/sequencer


  F.  Standard Braille Dot Numbering Convention

  A standard braille cell consists of six dots arranged in three rows
  and two columns.  Each dot can be specifically identified by its
  number as follows:

     1  Top-left (row 1, column 1).

     2  Middle-left (row 2, column 1).

     3  Bottom-left (row 3, column 1).

     4  Top-right (row 1, column 2).

     5  Middle-right (row 2, column 2).

     6  Bottom-right (row 3, column 2).

  Computer braille has introduced a fourth row at the bottom.

     7  Below-left (row 4, column 1).

     8  Below-right (row 4, column 2).

  Perhaps a picture will make this numbering convention easier to
  understand.


       1 o o 4
       2 o o 5
       3 o o 6
       7 o o 8

  G.  North American Braille Computer Code



         Num Hex     Dots     Description
       +-----------------------------------------------------------------+
       |   0  00  [7   4  8]  NUL (null)                                 |
       |   1  01  [7  1   8]  SOH (start of header)                      |
       |   2  02  [7 21   8]  STX (start of text)                        |
       |   3  03  [7  14  8]  ETX (end of text)                          |
       |   4  04  [7  145 8]  EOT (end of transmission)                  |
       |   5  05  [7  1 5 8]  ENQ (enquiry)                              |
       |   6  06  [7 214  8]  ACK (acknowledge)                          |
       |   7  07  [7 2145 8]  BEL (bell)                                 |
       |   8  08  [7 21 5 8]  BS (back space)                            |
       |   9  09  [7 2 4  8]  HT (horizontal tab)                        |
       |  10  0A  [7 2 45 8]  LF (line feed)                             |
       |  11  0B  [73 1   8]  VT (vertical tab)                          |
       |  12  0C  [7321   8]  FF (form feed)                             |
       |  13  0D  [73 14  8]  CR (carriage return)                       |
       |  14  0E  [73 145 8]  SO (shift out)                             |
       |  15  0F  [73 1 5 8]  SI (shift in)                              |
       |  16  10  [73214  8]  DLE (data link escape)                     |
       |  17  11  [732145 8]  DC1 (direct control 1)                     |
       |  18  12  [7321 5 8]  DC2 (direct control 2)                     |
       |  19  13  [732 4  8]  DC3 (direct control 3)                     |
       |  20  14  [732 45 8]  DC4 (direct control 4)                     |
       |  21  15  [73 1  68]  NAK (negative acknowledge)                 |
       |  22  16  [7321  68]  SYN (synchronize)                          |
       |  23  17  [7 2 4568]  ETB (end of text block)                    |
       |  24  18  [73 14 68]  CAN (cancel)                               |
       |  25  19  [73 14568]  EM (end of medium)                         |
       |  26  1A  [73 1 568]  SUB (substitute)                           |
       |  27  1B  [7 2 4 68]  ESC (escape)                               |
       |  28  1C  [7 21 568]  FS (file separator)                        |
       |  29  1D  [7 214568]  GS (group separator)                       |
       |  30  1E  [7   45 8]  RS (record separator)                      |
       |  31  1F  [7   4568]  US (unit separator)                        |
       |  32  20  [        ]  space                                      |
       |  33  21  [ 32 4 6 ]  exclamation point                          |
       |  34  22  [     5  ]  quotation mark                             |
       |  35  23  [ 3  456 ]  number sign                                |
       |  36  24  [  214 6 ]  dollar sign                                |
       |  37  25  [   14 6 ]  percent sign                               |
       |  38  26  [ 3214 6 ]  ampersand                                  |
       |  39  27  [ 3      ]  acute accent                               |
       |  40  28  [ 321 56 ]  left parenthesis                           |
       |  41  29  [ 32 456 ) right parenthesis                          |
       |  42  2A  [   1  6 ]  asterisk                                   |
       |  43  2B  [ 3  4 6 ]  plus sign                                  |
       |  44  2C  [      6 ]  comma                                      |
       |  45  2D  [ 3    6 ]  minus sign                                 |
       |  46  2E  [    4 6 ]  period                                     |
       |  47  2F  [ 3  4   ]  forward slash                              |
       |  48  30  [ 3   56 ]  zero                                       |
       |  49  31  [  2     ]  one                                        |
       |  50  32  [ 32     ]  two                                        |
       |  51  33  [  2  5  ]  three                                      |
       |  52  34  [  2  56 ]  four                                       |
       |  53  35  [  2   6 ]  five                                       |
       |  54  36  [ 32  5  ]  six                                        |
       |  55  37  [ 32  56 ]  seven                                      |
       |  56  38  [ 32   6 ]  eight                                      |
       |  57  39  [ 3   5  ]  nine                                       |
       |  58  3A  [   1 56 ]  colon                                      |
       |  59  3B  [     56 ]  semicolon                                  |
       |  60  3C  [  21  6 ]  less-than sign                             |
       |  61  3D  [ 321456 ]  equals sign                                |
       |  62  3E  [ 3  45  ]  greater-than sign                          |
       |  63  3F  [   1456 ]  question mark                              |
       |  64  40  [7   4   ]  commercial at                              |
       |  65  41  [7  1    ]  capital a                                  |
       |  66  42  [7 21    ]  capital b                                  |
       |  67  43  [7  14   ]  capital c                                  |
       |  68  44  [7  145  ]  capital d                                  |
       |  69  45  [7  1 5  ]  capital e                                  |
       |  70  46  [7 214   ]  capital f                                  |
       |  71  47  [7 2145  ]  capital g                                  |
       |  72  48  [7 21 5  ]  capital h                                  |
       |  73  49  [7 2 4   ]  capital i                                  |
       |  74  4A  [7 2 45  ]  capital j                                  |
       |  75  4B  [73 1    ]  capital k                                  |
       |  76  4C  [7321    ]  capital l                                  |
       |  77  4D  [73 14   ]  capital m                                  |
       |  78  4E  [73 145  ]  capital n                                  |
       |  79  4F  [73 1 5  ]  capital o                                  |
       |  80  50  [73214   ]  capital p                                  |
       |  81  51  [732145  ]  capital q                                  |
       |  82  52  [7321 5  ]  capital r                                  |
       |  83  53  [732 4   ]  capital s                                  |
       |  84  54  [732 45  ]  capital t                                  |
       |  85  55  [73 1  6 ]  capital u                                  |
       |  86  56  [7321  6 ]  capital v                                  |
       |  87  57  [7 2 456 ]  capital w                                  |
       |  88  58  [73 14 6 ]  capital x                                  |
       |  89  59  [73 1456 ]  capital y                                  |
       |  90  5A  [73 1 56 ]  capital z                                  |
       |  91  5B  [7 2 4 6 ]  left bracket                               |
       |  92  5C  [7 21 56 ]  backward slash                             |
       |  93  5D  [7 21456 ]  right bracket                              |
       |  94  5E  [7   45  ]  circumflex accent                          |
       |  95  5F  [    456 ]  underscore                                 |
       |  96  60  [    4   ]  grave accent                               |
       |  97  61  [   1    ]  small a                                    |
       |  98  62  [  21    ]  small b                                    |
       |  99  63  [   14   ]  small c                                    |
       | 100  64  [   145  ]  small d                                    |
       | 101  65  [   1 5  ]  small e                                    |
       | 102  66  [  214   ]  small f                                    |
       | 103  67  [  2145  ]  small g                                    |
       | 104  68  [  21 5  ]  small h                                    |
       | 105  69  [  2 4   ]  small i                                    |
       | 106  6A  [  2 45  ]  small j                                    |
       | 107  6B  [ 3 1    ]  small k                                    |
       | 108  6C  [ 321    ]  small l                                    |
       | 109  6D  [ 3 14   ]  small m                                    |
       | 110  6E  [ 3 145  ]  small n                                    |
       | 111  6F  [ 3 1 5  ]  small o                                    |
       | 112  70  [ 3214   ]  small p                                    |
       | 113  71  [ 32145  ]  small q                                    |
       | 114  72  [ 321 5  ]  small r                                    |
       | 115  73  [ 32 4   ]  small s                                    |
       | 116  74  [ 32 45  ]  small t                                    |
       | 117  75  [ 3 1  6 ]  small u                                    |
       | 118  76  [ 321  6 ]  small v                                    |
       | 119  77  [  2 456 ]  small w                                    |
       | 120  78  [ 3 14 6 ]  small x                                    |
       | 121  79  [ 3 1456 ]  small y                                    |
       | 122  7A  [ 3 1 56 ]  small z                                    |
       | 123  7B  [  2 4 6 ]  left brace                                 |
       | 124  7C  [  21 56 ]  vertical bar                               |
       | 125  7D  [  21456 ]  right brace                                |
       | 126  7E  [    45  ]  tilde accent                               |
       | 127  7F  [7   456 ]  DEL (delete)                               |
       | 128  80  [    4  8]  <control>                                  |
       | 129  81  [   1   8]  <control>                                  |
       | 130  82  [  21   8]  BPH (break permitted here)                 |
       | 131  83  [   14  8]  NBH (no break here)                        |
       | 132  84  [   145 8]  <control>                                  |
       | 133  85  [   1 5 8]  NL (next line)                             |
       | 134  86  [  214  8]  SSA (start of selected area)               |
       | 135  87  [  2145 8]  ESA (end of selected area)                 |
       | 136  88  [  21 5 8]  CTS (character tabulation set)             |
       | 137  89  [  2 4  8]  CTJ (character tabulation justification)   |
       | 138  8A  [  2 45 8]  LTS (line tabulation set)                  |
       | 139  8B  [ 3 1   8]  PLD (partial line down)                    |
       | 140  8C  [ 321   8]  PLU (partial line up)                      |
       | 141  8D  [ 3 14  8]  RLF (reverse line feed)                    |
       | 142  8E  [ 3 145 8]  SS2 (single shift two)                     |
       | 143  8F  [ 3 1 5 8]  SS3 (single shift three)                   |
       | 144  90  [ 3214  8]  DCS (device control string)                |
       | 145  91  [ 32145 8]  PU1 (private use one)                      |
       | 146  92  [ 321 5 8]  PU2 (private use two)                      |
       | 147  93  [ 32 4  8]  STS (set transmit state)                   |
       | 148  94  [ 32 45 8]  CC (cancel character)                      |
       | 149  95  [ 3 1  68]  MW (message waiting)                       |
       | 150  96  [ 321  68]  SGA (start of guarded area)                |
       | 151  97  [  2 4568]  EGA (end of guarded area)                  |
       | 152  98  [ 3 14 68]  SS (start of string)                       |
       | 153  99  [ 3 14568]  <control>                                  |
       | 154  9A  [ 3 1 568]  SCI (single character introducer)          |
       | 155  9B  [  2 4 68]  CSI (control sequence introducer)          |
       | 156  9C  [  21 568]  ST (string terminator)                     |
       | 157  9D  [  214568]  OSC (operating system command)             |
       | 158  9E  [    45 8]  PM (privacy message)                       |
       | 159  9F  [    4568]  APC (application program command)          |
       | 160  A0  [7      8]  no-break space                             |
       | 161  A1  [732 4 6 ]  inverted exclamation mark                  |
       | 162  A2  [7 214 6 ]  cent sign                                  |
       | 163  A3  [73  456 ]  pound sign                                 |
       | 164  A4  [7  14 6 ]  currency sign                              |
       | 165  A5  [73214 6 ]  yen sign                                   |
       | 166  A6  [7  1 56 ]  broken bar                                 |
       | 167  A7  [73   5  ]  section sign                               |
       | 168  A8  [7    5  ]  diaeresis                                  |
       | 169  A9  [732  56 ]  copyright sign                             |
       | 170  AA  [       8]  feminine ordinal indicator                 |
       | 171  AB  [7 21  6 ]  left-pointing double angle quotation mark  |
       | 172  AC  [7 2  56 ]  not sign                                   |
       | 173  AD  [73    6 ]  soft hyphen                                |
       | 174  AE  [732   6 ]  registered sign                            |
       | 175  AF  [7 2   6 ]  macron                                     |
       | 176  B0  [73   56 ]  degree sign                                |
       | 177  B1  [73  4 6 ]  plus-minus sign                            |
       | 178  B2  [732     ]  superscript two                            |
       | 179  B3  [7 2  5  ]  superscript three                          |
       | 180  B4  [73      ]  acute accent                               |
       | 181  B5  [7    56 ]  micro sign                                 |
       | 182  B6  [732  5  ]  pilcrow sign                               |
       | 183  B7  [7   4 6 ]  middle dot                                 |
       | 184  B8  [7     6 ]  cedilla                                    |
       | 185  B9  [7 2     ]  superscript one                            |
       | 186  BA  [7       ]  masculine ordinal indicator                |
       | 187  BB  [73  45  ]  right-pointing double angle quotation mark |
       | 188  BC  [7321 56 ]  vulgar fraction one quarter                |
       | 189  BD  [7321456 ]  vulgar fraction one half                   |
       | 190  BE  [732 456 ]  vulgar fraction three quarters             |
       | 191  BF  [7  1456 ]  inverted question mark                     |
       | 192  C0  [732  5 8]  capital a grave                            |
       | 193  C1  [7  1  68]  capital a acute                            |
       | 194  C2  [7 2    8]  capital a circumflex                       |
       | 195  C3  [7    5 8]  capital a tilde                            |
       | 196  C4  [73214 68]  capital a diaeresis                        |
       | 197  C5  [73  45 8]  capital a ring above                       |
       | 198  C6  [73     8]  capital ae                                 |
       | 199  C7  [73  4 68]  capital c cedilla                          |
       | 200  C8  [732  568]  capital e grave                            |
       | 201  C9  [7 21  68]  capital e acute                            |
       | 202  CA  [732    8]  capital e circumflex                       |
       | 203  CB  [73214568]  capital e diaeresis                        |
       | 204  CC  [732   68]  capital i grave                            |
       | 205  CD  [7  14 68]  capital i acute                            |
       | 206  CE  [7 2  5 8]  capital i circumflex                       |
       | 207  CF  [7321 568]  capital i diaeresis                        |
       | 208  D0  [7     68]  capital eth                                |
       | 209  D1  [7   4 68]  capital n tilde                            |
       | 210  D2  [73   5 8]  capital o grave                            |
       | 211  D3  [7  14568]  capital o acute                            |
       | 212  D4  [7 2  568]  capital o circumflex                       |
       | 213  D5  [7    568]  capital o tilde                            |
       | 214  D6  [732 4 68]  capital o diaeresis                        |
       | 215  D7  [7  1  6 ]  multiplication sign                        |
       | 216  D8  [73  4  8]  capital o stroke                           |
       | 217  D9  [73   568]  capital u grave                            |
       | 218  DA  [7  1 568]  capital u acute                            |
       | 219  DB  [7 2   68]  capital u circumflex                       |
       | 220  DC  [732 4568]  capital u diaeresis                        |
       | 221  DD  [7 214 68]  capital y acute                            |
       | 222  DE  [73    68]  capital thorn                              |
       | 223  DF  [73  4568]  small sharp s                              |
       | 224  E0  [ 32  5 8]  small a grave                              |
       | 225  E1  [   1  68]  small a acute                              |
       | 226  E2  [  2    8]  small a circumflex                         |
       | 227  E3  [     5 8]  small a tilde                              |
       | 228  E4  [ 3214 68]  small a diaeresis                          |
       | 229  E5  [ 3  45 8]  small a ring above                         |
       | 230  E6  [ 3     8]  small ae                                   |
       | 231  E7  [ 3  4 68]  small c cedilla                            |
       | 232  E8  [ 32  568]  small e grave                              |
       | 233  E9  [  21  68]  small e acute                              |
       | 234  EA  [ 32    8]  small e circumflex                         |
       | 235  EB  [ 3214568]  small e diaeresis                          |
       | 236  EC  [ 32   68]  small i grave                              |
       | 237  ED  [   14 68]  small i acute                              |
       | 238  EE  [  2  5 8]  small i circumflex                         |
       | 239  EF  [ 321 568]  small i diaeresis                          |
       | 240  F0  [      68]  small eth                                  |
       | 241  F1  [    4 68]  small n tilde                              |
       | 242  F2  [ 3   5 8]  small o grave                              |
       | 243  F3  [   14568]  small o acute                              |
       | 244  F4  [  2  568]  small o circumflex                         |
       | 245  F5  [     568]  small o tilde                              |
       | 246  F6  [ 32 4 68]  small o diaeresis                          |
       | 247  F7  [73  4   ]  division sign                              |
       | 248  F8  [ 3  4  8]  small o stroke                             |
       | 249  F9  [ 3   568]  small u grave                              |
       | 250  FA  [   1 568]  small u acute                              |
       | 251  FB  [  2   68]  small u circumflex                         |
       | 252  FC  [ 32 4568]  small u diaeresis                          |
       | 253  FD  [  214 68]  small y acute                              |
       | 254  FE  [ 3    68]  small thorn                                |
       | 255  FF  [ 3  4568]  small y diaeresis                          |
       +-----------------------------------------------------------------+

  H.  MIDI Instrument Table


           _____________________________________________________________
           Piano                    0   Acoustic Grand Piano
                                    1   Bright Acoustic Piano
                                    2   Electric Grand Piano
                                    3   Honkytonk Piano
                                    4   Electric Piano 1
                                    5   Electric Piano 2
                                    6   Harpsichord
                                    7   Clavi
           _____________________________________________________________
           Chromatic Percussion     8   Celesta
                                    9   Glockenspiel
                                   10   Music Box
                                   11   Vibraphone
                                   12   Marimba
                                   13   Xylophone
                                   14   Tubular Bells
                                   15   Dulcimer
           _____________________________________________________________
           Organ                   16   Drawbar Organ
                                   17   Percussive Organ
                                   18   Rock Organ
                                   19   Church Organ
                                   20   Reed Organ
                                   21   Accordion
                                   22   Harmonica
                                   23   Tango Accordion
           _____________________________________________________________
           Guitar                  24   Nylon Acoustic Guitar
                                   25   Steel Acoustic Guitar
                                   26   Jazz Electric Guitar
                                   27   Clean Electric Guitar
                                   28   Muted Electric Guitar
                                   29   Overdriven Guitar
                                   30   Distortion Guitar
                                   31   Guitar Harmonics
           _____________________________________________________________
           Bass                    32   Acoustic Bass
                                   33   Finger Electric Bass
                                   34   Pick Electric Bass
                                   35   Fretless Bass
                                   36   Slap Bass 1
                                   37   Slap Bass 2
                                   38   Synth Bass 1
                                   39   Synth Bass 2
           _____________________________________________________________
           Strings                 40   Violin
                                   41   Viola
                                   42   Cello
                                   43   Contrabass
                                   44   Tremolo Strings
                                   45   Pizzicato Strings
                                   46   Orchestral Harp
                                   47   Timpani
           _____________________________________________________________
           Ensemble                48   String Ensemble 1
                                   49   String Ensemble 2
                                   50   Synth Strings 1
                                   51   Synth Strings 2
                                   52   Choir Aahs
                                   53   Voice Oohs
                                   54   Synth Voice
                                   55   Orchestra Hit
           _____________________________________________________________
           Brass                   56   Trumpet
                                   57   Trombone
                                   58   Tuba
                                   59   Muted Trumpet
                                   60   French Horn
                                   61   Brass Section
                                   62   Synth Brass 1
                                   63   Synth Brass 2
           _____________________________________________________________
           Reed                    64   Soprano Saxophone
                                   65   Alto Saxophone
                                   66   Tenor Saxophone
                                   67   Baritone Saxophone
                                   68   Oboe
                                   69   English Horn
                                   70   Bassoon
                                   71   Clarinet
           _____________________________________________________________
           Pipe                    72   Piccolo
                                   73   Flute
                                   74   Recorder
                                   75   Pan Flute
                                   76   Blown Bottle
                                   77   Shakuhachi
                                   78   Whistle
                                   79   Ocarina
           _____________________________________________________________
           Synth Lead              80   Lead 1 (square)
                                   81   Lead 2 (sawtooth)
                                   82   Lead 3 (calliope)
                                   83   Lead 4 (chiff)
                                   84   Lead 5 (charang)
                                   85   Lead 6 (voice)
                                   86   Lead 7 (fifths)
                                   87   Lead 8 (bass + lead)
           _____________________________________________________________
           Synth Pad               88   Pad 1 (new age)
                                   89   Pad 2 (warm)
                                   90   Pad 3 (polysynth)
                                   91   Pad 4 (choir)
                                   92   Pad 5 (bowed)
                                   93   Pad 6 (metallic)
                                   94   Pad 7 (halo)
                                   95   Pad 8 (sweep)
           _____________________________________________________________
           Synth FM                96   FX 1 (rain)
                                   97   FX 2 (soundtrack)
                                   98   FX 3 (crystal)
                                   99   FX 4 (atmosphere)
                                  100   FX 5 (brightness)
                                  101   FX 6 (goblins)
                                  102   FX 7 (echoes)
                                  103   FX 8 (science-fiction)
           _____________________________________________________________
           Ethnic                 104   Sitar
                                  105   Banjo
                                  106   Shamisen
                                  107   Koto
                                  108   Kalimba
                                  109   Bag Pipe
                                  110   Fiddle
                                  111   Shanai
           _____________________________________________________________
           Percussive             112   Tinkle Bell
                                  113   Agogo
                                  114   Steel Drum
                                  115   Wooden Block
                                  116   Taiko Drum
                                  117   Melodic Tom
                                  118   Synth Drum
                                  119   Reverse Cymbal
           _____________________________________________________________
           Sound Effects          120   Guitar Fret Noise
                                  121   Breath Noise
                                  122   Seashore
                                  123   Bird Tweet
                                  124   Telephone Ring
                                  125   Helicopter
                                  126   Applause
                                  127   Gunshot



