Braille typewriter. Braille keyboard for an old typewriter. The sliding pointer (lower centre) is adjusted to select the desired letter, number, or punctuation mark. The raised braille dots enable a blind person to identify the character selected. Here, the letter 'l' has been selected, shown by a vertical line of three dots. Elsewhere on the typewriter is a key that is struck to print the letter selected. Braille was invented by Louis Braille (1809-1852). The first typewriters were built in the 1870s.