Chorded keyboard (a writing system for the blind) uses either 6 or 8 tactile 'points' from which all letters and numbers are formed. When Louis Braille invented it, it was produced with a needle holing successively all needed points in a cardboard sheet. In 1892, Frank Haven Hall, superintendent of the Illinois Institute for the Education of the Blind, created the Hall Braille Writer, which was like a typewriter with 6 keys, one for each dot in a braille cell. The Perkins Brailler, first manufactured in 1951, uses a 6-key chord keyboard (plus a spacebar) to produce braille output, and has been
Louis Braille affair, but it provided a relatively stable environment for blind children to learn and associate together. The children were taught how to read by a system devised by the school's founder, Valentin Haüy. Not blind himself, Haüy was a philanthropist who devoted his life to helping the blind. He designed and manufactured a small library of books for the children using a technique of embossing heavy paper with the raised imprints of Latin letters. Readers would trace their fingers over the text, comprehending slowly but in a traditional fashion which Haüy could appreciate. Braille was helped by the Haüy books,