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<!-- retain these comments for translator revision tracking -->
<!-- $Id$ -->
<sect1 id="boot-installer-accessibility" arch="not-s390">
<title>Accessibility</title>
<para>
Some users may need specific support because of e.g. some visual
impairment.
<phrase arch="ia64;powerpc;x86">USB braille displays are detected
automatically, but most other</phrase>
<phrase arch="arm;hppa;mips;mipsel;sparc">Most</phrase>
accessibility features have to be enabled manually.
<phrase arch="x86">On machines that support it, the boot menu emits a beep
when it is ready to receive keystrokes.</phrase>
Some boot parameters can <phrase arch="x86">then</phrase> be appended to
enable accessibility features<phrase arch="x86"> (see also
<xref linkend="boot-screen"/>)</phrase>.
Note that on most architectures the boot loader interprets your keyboard as
a QWERTY keyboard.
</para>
<sect2 arch="ia64;powerpc;x86">
<title>USB Braille Displays</title>
<para>
USB braille displays should be automatically detected. A textual version
of the installer will then be automatically selected, and support for the
braille display will be automatically installed on the target system.
You can thus just press &enterkey; at the boot menu.
Once <classname>brltty</classname> is started, you can choose a braille
table by entering the preference menu. Documentation on key
bindings for braille devices is available on the <ulink
url="&url-brltty-driver-help;"><classname>brltty</classname> website</ulink>.
</para>
</sect2>
<sect2 arch="ia64;powerpc;x86">
<title>Serial Braille Displays</title>
<para>
Serial braille displays cannot safely be automatically detected
(since that may damage some of them). You thus need to append the
<userinput>brltty=<replaceable>driver</replaceable>,<replaceable>port</replaceable>,<replaceable>table</replaceable></userinput>
boot parameter to tell <classname>brltty</classname> which driver it
should use. <replaceable>driver</replaceable> should be replaced by the
two-letter driver code for your terminal (see the
<ulink url="&url-brltty-driver-codes;">driver code list</ulink>).
<replaceable>port</replaceable> should be replaced by the name of the
serial port the display is connected to, <userinput>ttyS0</userinput> is
the default. <replaceable>table</replaceable> is the name of the braille
table to be used (see the <ulink url="&url-brltty-table-codes;">table code
list</ulink>); the English table is the default. Note that the table can
be changed later by entering the preference menu. Documentation on key
bindings for braille devices is available on the <ulink
url="&url-brltty-driver-help;"><classname>brltty</classname> website</ulink>.
</para>
</sect2>
<sect2 arch="x86">
<title>Hardware Speech Synthesis</title>
<para>
Support for hardware speech synthesis devices is available only alongside
support for graphical installer. You thus need to select the
<quote>Graphical install</quote> entry in the boot menu.
</para><para>
Hardware speech synthesis devices cannot be automatically detected. You
thus need to append the
<userinput>speakup.synth=<replaceable>driver</replaceable></userinput>
boot parameter to tell <classname>speakup</classname> which driver it should
use. <replaceable>driver</replaceable> should be replaced by the driver code
for your device (see <ulink url="&url-speakup-driver-codes;">driver code
list</ulink>). The textual version of the installer will then be
automatically selected, and support for the speech synthesis device will be
automatically installed on the target system.
</para>
</sect2>
<sect2><title>Board Devices</title>
<para>
Some accessibility devices are actual boards that are plugged inside the
machine and that read text directly from the video memory. To get them
to work framebuffer support must be disabled by using the
<userinput arch="x86">vga=normal</userinput> <userinput>fb=false</userinput>
boot parameter. This will however reduce the number of available languages.
</para><para arch="x86">
If desired a textual version of the bootloader can be activated before adding
the boot parameter by typing <userinput>h</userinput> &enterkey;.
</para>
</sect2>
<sect2><title>High-Contrast Theme</title>
<para>
For users with low vision, the installer can use a high-contrast
theme that makes it more readable. To enable it, append the
<userinput>theme=dark</userinput> boot parameter.
</para>
</sect2>
</sect1>
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