Each braille cell is comprised of six raised dots. These dots are numbered and each dot is well-known under its number. The dots 1 and 4 form the top pair, 2 and 5 the middle pair and 3 and 6 the bottom pair. In other words, The left side of the basic braille cell consists of the dots 1, 2 and 3, the right one of the dots 4, 5 and 6.
63 simple characters can be formed by these six dots. These 63 characters are divided in 7 groups. I explain only three of them.
The characters of the first group are formed by the dots 1, 2, 4 and 5. They represent the first 10 letters of the alphabet: "a – j".
The second group is formed by adding the dot 3 to the characters of the first group. They represent the second 10 letters of the alphabet: "k – t".
The third group is formed by adding the dots 3 and 6 to the 5 first characters of the first group. They represent the last letters of the alphabet with the exception of "w": "u, v, x, y and z".
NUMBERS
= 1
= 2
= 3
= 4
= 5
= 6
= 7
= 8
= 9
= 10
GROUP 1 GROUP 2 GROUP 3
a =
u =
b =
v =
c =
x =
d =
y =
e =
z =
f =
w =
g =
h =
i =
j =
Because 63 characters cannot cover all possible print signs and their variants, it is necessary to use multi-character sequences. By looking at the table above, you see that braille numbers are announced by a sign using dots 3, 4, 5 and 6. The use of dot 6 just before a letter indicates a capital.
Because of space problems and for more rapid reading and writing, the braille codes for many languages employ contractions that substitute shorter sequences for the full spelling of commonly-occurring letter groups.
The norm for computers is an 8-bit byte which allows for 256 characters. Especially for purposes related to computer access, there is some use of 8-dot braille formed by adding a dot position to each column. However, due to cell size and other considerations, six-dot braille still seems to represent the best system for general reading purposes.
