Refreshable braille display

Similar to the Perkins Brailler, the input is performed by two sets of four keys on each side, while output is via a refreshable braille display consisting of a row of electro-mechanical character cells, each of which can raise or lower a combination of eight round-tipped pins.

Other variants exist that use a conventional QWERTY keyboard for input and braille pins for output, as well as input-only and output-only devices.

The software gathers the content of the screen from the operating system, converts it into braille characters and sends it to the display.

Modern operating systems usually have an API to help screen readers obtain this information, such as UI Automation (UIA) for Microsoft Windows, VoiceOver for macOS and iOS, and AT-SPI for GNOME.

A rotating-wheel Braille display was developed in 2000 by the National Institute of Standards and Technology (NIST) and another at the Leuven University in Belgium.