Current File : //usr/share/doc/brltty/Voyager.README
BRLTTY Driver for the Tieman Voyager Braille Display
This is the user-space-only version of the driver.
Version 0.10 (March 2004)
Copyright 2004 by St�phane Doyon <s.doyon@videotron.ca>
This is a partial rewrite of the driver which functions entirely from
user-space (whereas the previous driver depended on a kernel driver for
the USB communication with the Voyager display).
This driver supports the Tieman Voyager 44 and 70.
The driver works with later 2.4.x kernels and with at least some versions
in the 2.6.x series.
Note that the kernel brlvger driver used with the old BRLTTY driver does
not work properly with 2.6.x kernels.
Many thanks to the Tieman people: Corand van Strien, Ivar Illing, Daphne
Vogelaar and Ingrid Vogel. They provided us with a Braille display (as
well as programming information) so that we could write this driver. They
replaced the display when it broke and they answered our technical
questions. It is very motivating when companies take an interest in such
projects and are so supportive.
Thanks to Andor Demarteau <ademarte@students.cs.uu.nl> who got this whole
project started and beta-tested all our early buggy attempts.
Thanks to St�phane Dalton who wrote the initial version of the old kernel
driver. Without his initiative this project would not have been a success.
This rewrite of the driver should allow more flexibility, but is as of yet
very young and not thoroughly tested.
When BRLTTY will be running, press the leftmost routing key to bring up
the help screen so you can read the details of the key bindings.
Users of the 2.6.x kernel may experience some difficulties. The old
kernel driver, which is included in the official kernels, will actually
get in the way of this driver as it will claim the USB interface to the
display, and I've seen some hangs occur when BRLTTY asks to disconnect
the kernel driver. If you have this problem you should make sure the
kernel module called brlvger is not inserted into your kernel. One simple
way to prevent that module from auto-loading is to rename the module file
so it isn't found.
cd /lib/modules/`uname -r`/kernel/drivers/usb/
mv brlvger.o brlvger.o.hold
If lsmod shows the brlvger module as already loaded then do
rmmod brlvger
The old kernel driver will soon be pulled out of 2.6.x kernels.
BRLTTY currently assumes the default braille device to be a serial port,
so you must tell it that it is in fact USB.
Either provide the "--with-braille-device=usb:" option when running the
BRLTTY top-level ./configure command, or use the braille-device parameter
in your BRLTTY configuration file (/etc/brltty.conf):
braille-device usb:
If you actually have more than one Voyager display connected at the same
time, you can also specify the serial number of the device that you want
to use.
This driver knows a number of driver parameters which you can pass via
the braille-parameters clause in your BRLTTY configuration file
(/etc/brltty.conf) or via brltty's -B (--braille-parameters=) command
line option.
InputMode: This parameter specifies whether or not the eight top keys
function as a braille keyboard. When set to "no" (the default), top
key combinations perform various navigational and operational
functions. When set to yes", they function as an 8-dot braille
keyboard. If B, C, or B+C is pressed along with any top key
combination then it's as if this parameter were set to "no".
There are only a handful of BRLTTY users, so if you are trying out this
driver, please drop us a note, even if you have no problems!
Note to BRLTTY developers: This is my first attempt at combining the key
binding definitions with the help file text in one place, through
annotations in the braille.c file. If you change the key bindings,
currently you need python installed to be able to rebuild the help
files.
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