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
Mesoamerican writing systems Mesoamerican writing system. They can be seen to contain calendric information but are otherwise undeciphered. The longest of these texts are on La Mojarra Stela 1 and the Tuxtla Statuette. The writing system used is very close to the Maya script, using affixal glyphs and Long Count dates, but is read only in one column at a time as is the Zapotec script. It has been suggested that this Isthmian or Epi-Olmec script is the direct predecessor of the Maya script, thus giving the Maya script a non-Maya origin. Another artifact with Epi-Olmec script is the Chiapa de Corzo stela