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
Mini blind devices which are used to upgrade the blind but is not considered the safest alternative according to the US.CPSC, who recommends using only cordless window coverings in homes where small children live or visit. Blinds with wand tilt are safer than blinds with traditional cord tilt. There are also cordless blinds. The dangling group of pull cords is replaced by a spring motor system. A push or pull on the bottom bar raises or lowers the mini blind rather than using pull cords. Slats are made by continuous casting. Casting is the pouring of molten metal or plastic into a