5.2. 辅助功能

一些用户,比如有视觉障碍的,可能需要特别的支持。USB(不含通过串口 USB 转换口转换的) 盲文点字显示器(braille displays)可以自动检测到,但多数情况下其他的 辅助功能不得不通过手动进行设置。 一些引导参数可以 被添加到后面打开这些辅助功能。需要注意在大多数架构下 boot loader 将视您的键盘为 QWERTY 布局。

5.2.1. Installer front-end

The Debian installer supports several front-ends for asking questions, with varying convenience for accessibility: notably, text uses plain text while newt uses text-based dialog boxes. The choice can be made at the boot prompt, see the documentation for DEBIAN_FRONTEND in 第 5.3.2 节 “Debian 安装程序的参数”.

5.2.2. USB 盲文点显器

系统应该可以自动检测到 USB 盲文点显器。然后自动选取安装程序的文本界面,该设备也会被自动安装到最终系统中。您只需要在引导菜单中按下 Enter 键。一旦 brltty 启动,您就可以通过菜单选择 braille table。在 brltty website 可以找到盲文点显器的键绑定文档。

5.2.3. 串口盲文点显器

Serial braille displays cannot safely be automatically detected (since that may damage some of them). You thus need to append the brltty=driver,port boot parameter to tell brltty which driver and port it should use. driver should be replaced by the two-letter driver code for your terminal (see the BRLTTY manual). port should be replaced by the name of the serial port the display is connected to, ttyS0 is the default, ttyUSB0 can be typically used when using a serial-to-USB converter. A third parameter can be provided, to choose the name of the braille table to be used (see the BRLTTY manual); the English table is the default. Note that the table can be changed later by entering the preference menu. A fourth parameter can be provided to pass parameters to the braille driver, such as protocol=foo which is needed for some rare models. Documentation on key bindings for braille devices is available on the brltty website.

5.2.4. 板卡设备

一些辅助设备实际上是插入计算机里面的板卡,它们直接从显存里面读取字符。要让它们工作,需要使用引导参数 fb=false 禁止使用 framebuffer。然而这会减少可用语言的数量。

5.2.5. 高亮主题

For users with low vision, the installer can use a high-contrast color theme that makes it more readable. To enable it, append the theme=dark boot parameter.

5.2.6. Zoom

For users with low vision, the graphical installer has a very basic zoom support: the Control++ and Control+- shortcuts increase and decrease the font size.

5.2.7. 预置

另外,Debian 可以使用预置进行完全自动安装。相关文档参见 附录 B, 使用预置自动进行安装

5.2.8. Accessibility of the installed system

Documentation on accessibility of the installed system is available on the Debian Accessibility wiki page.