Braille is a tactile writing system used by blind people. It was invented by Louis Braille of France who was blinded in a childhood accident. At the age of 15 he invented a code based on a military system for reading orders at night without showing any light. Braille originally lacked an encoding for the letter W.
Braille is also notable for being a binary code that predated the invention of the computer.
Braille generally consists of cells of 6 raised dots conventionally numbered
Braille has been extended to an 8 dot code so that the case of an individual letter is directly coded in that cell, and so that all the printable ASCII characters can be represented. All 256 possible combinations of 8 dots are encoded by the Unicode standard.
Braille may be produced using a "slate" and a "stylus" in which each dot is created from the back of the page, writing in mirror image, by hand, or it may be produced on a braille typewriter or "brailler", or produced by a Braille Embosser attached to a computer. It may also be rendered using a refreshable braille display.
A1 B2 C3 D4 E5 F6 G7 H8 I9 J0 X. X. XX XX X. XX XX X. .X .X .. X. .. .X .X X. XX XX X. XX .. .. .. .. .. .. .. .. .. ..Next time you're in an elevator, check the braille:
K L M N O P Q R S T X. X. XX XX X. XX XX X. .X .X .. X. .. .X .X X. XX XX X. XX X. X. X. X. X. X. X. X. X. X.
U V W X Y Z X. X. .X XX XX X. .. X. XX .. .X .X XX XX .X XX XX XX
Capital Number Question sign sign Period Comma mark .. .X .. .. .. .. .X XX X. X. .X XX .X .. XX
Exclam. Opening Closing Semicolon point quote quote Bracket Hyphen .. .. .. .. .. .. X. XX X. .X XX .. X. X. XX XX XX XX
.X XX .X X. XX ..... means this is the button for the sixth floor (number sign + F).
The Braille alphabet in Unicode characters:
|⠓||H 8||⠠||Capital sign|
|⠊||I 9||⠼||Number sign|