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Encoding information. J.-D. Chatelain. Almost whole Humanity today uses the same ten symbols called "Arabic numerals" and scored 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Counting. The ten symbols combined allow to represent any number that is said then expressed in base 10 , or as decimal .
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Encoding information J.-D. Chatelain
Almost whole Humanity today uses the same ten symbols called "Arabic numerals" and scored 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Counting The ten symbols combined allow to represent any number that is said then expressed inbase 10, or asdecimal. What does mean a number like8604? 8604 = 8 times 10 3 + 6 times 10 2 + 0 times 10 1 + 4 times 10 0 To represent numbers, men have first used the hand, which has led to the decimal base
0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 Imagine that instead of ten symbols, we do has only two, 0 and 1, called bits. Counting These two symbols, combined, can represent any number that is said then expressed inbase 2, or inbinary mode. What does mean a number like1101? 1101 = 1 times 2 3 + 1 times 2 2 + 0 times 2 1+ 1 times 2 0 = 13 A binary numbering system is used in electronics because it is easy to determine whether a switch is open or closed.
0 0 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 one byte 0 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 In computing, it has become customary to group the binary digits into words of eight bits or bytes Counting A byte allows to encode 2 8 = 256 different values. It is unthinkable to use a different symbol for each of 256 combinations allowed. However, splitting the byte into two 4-bit words, each word can encode 2 4 = 16 combinations. It is conceivable to assign a symbol to each of the 16 different values: These symbols, combined, can represent any number that is said then expressed in base 16, or in hex mode What does mean a number likeD3A? D3A = D(=13) times 16 2 + 3 times 16 1 + A(=10) times 16 0 = 3386
Example: encoding M: Hex Binary ASCII (American Standard Code for Information Interchange) used for encoding alphanumeric characters in computer 4 D 0100 1101
Encoding information End of this chapter J.-D. Chatelain