BRLTTY - Access software for Unix for a blind person using a soft Braille terminal Nikhil Nair Nicolas Pitre Stephane Doyon Version 1.0, 26 July 1996 Copyright (C) 1995, 1996 by Nikhil Nair and others. All rights reserved. BRLTTY comes with ABSOLUTELY NO WARRANTY. This is free software, placed under the terms of the GNU General Public License, as published by the Free Software Foundation. Please see the file COPYING, included in the BRLTTY distribution, for details. This software is maintained by Nikhil Nair . ----------------------------------------------------------------------------- INTRODUCTION FOR THOSE NEW TO SOFT BRAILLE ========================================== There are two common ways in which blind people access computers. The first, and more widely known, is synthesized speech, which, while having many advantages (e.g. speed for reading plain text), does have its drawbacks: speech output generally gives little information about formatting, making tables, spreadsheets etc. difficult to use; it can also be difficult to use speech output with particularly technical material containing lots of symbols (though many determined people do use it for such things). The other solution, which attempts to answer some of these problems, is Braille output. A soft (or refreshable) Braille display typically consists of a single row of either 20, 40 or 80 characters, each made up of a matrix of 4X2 (4 down, 2 across) dots. Each dot is individually driven by a separate motor, making the whole assembly extremely expensive. A soft Braille display would connect to a PC by either the serial or parallel port. Software on the PC drives the display, reproducing a rectangle of the screen image (which we will call the window) in Braille. Buttons on the Braille display itself are used to send signals back to the software, instructing it to move the window around the screen, or some other specialised function. With a soft Braille display of 40 or 80 cells, it is quite easy for a blind user to appreciate the format of information on the screen, and even allows the reading and editing of on-line Braille documents (a concept not widely enough utilised). INTRODUCTION TO BRLTTY ====================== While soft Braille displays have been used for some years under MS-DOS, and are even starting to be used under Windows, it seems that they have not been used on Unix consoles. This could well be because blind people have been able to access Unix systems through accessible terminals. With the advent of PC-based Unix systems (such as Linux), the need becomes evident. BRLTTY attempts to fill this gap. It runs as a daemon, possibly started at boot-time, and allows a soft Braille user to access text mode applications. Since BRLTTY is written as a daemon, it should allow a user a completely free choice of application and development tools. FEATURES ======== - Full implementation of the standard screen review facilities. - A wide range of additional optional features, including blinking cursor and capital letters, screen freezing for leisurely review, attribute display to locate highlighted text, hypertext links, etc. - `Intelligent' cursor routing. This allows easy movement of the cursor in text editors etc. without moving the hands from the Braille display. - A cut & paste function. This is particularly useful for copying long filenames, complicated commands etc. - An on-line help facility. - Support for multiple Braille codes. - Modular design allows relatively easy addition of drivers for other Braille displays, or even (hopefully) porting to other Unix-like platforms. CURRENTLY SUPPORTED HARDWARE ============================ BRLTTY requires Linux kernel 1.1.92 or later (for `/dev/vcsa0'). It has been tested on - a variety of PCs: both laptops and desktops; processors from 386SX20 to Pentium with a huge range of memory sizes; Linux distributions including Debian and Slackware; a number of Linux kernels, including both 1.2.13 and 2.0.0. - a DEC Alpha: only tested once, under RedHat Alpha Linux on a noname board kindly lent to the Cambridge University Computer Laboratory by DEC in Reading, England. The following Braille displays are supported (serial communication only): - Tieman B.V.: CombiBraille 25/45/85; - Alva B.V.: ABT3xx series; - Telesensory Systems Inc.: PowerBraille 40 (not 65/80), Navigator 20/40/80 (latest firmware version only?). If you want another Braille display to be supported, please contact the maintainer. Ability to add more Braille displays does, however, depend on the level of cooperation from the manufacturer in providing programming information. THE BRLTTY TEAM =============== There are currently three active developers: - Nikhil Nair: founder of the BRLTTY project and author of the Tieman B.V. CombiBraille driver E-Mail: nn201@cus.cam.ac.uk - Nicolas Pitre: Author of the driver for the Alva series E-Mail: nico@cam.org - Stephane Doyon: Author of the driver for the TSI displays (Navigator and PowerBraille 40) E-Mail: doyons@jsp.umontreal.ca Any comments and/or criticisms regarding BRLTTY in general should be addressed to all three of the above. In addition, James Bowden , the original coauthor, is now acting in an advisory capacity. LAYOUT OF THE ARCHIVE ===================== BRLTTY is distributed as a single GNU compressed tarfile named brltty-.tar.gz where `' is the version number. When the archive is unpacked, there should be a subdirectory called DOCS: this contains all of the general BRLTTY documentation, including the manual in various formats and the list of frequently asked questions (FAQ). The source files for the main, device-independent core of BRLTTY is in the top-level directory. There is also one subdirectory per Braille device type, containing display-specific source files and documentation (in another README file).