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Character coding schemes
Highcliffe School ICT Department
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Intro How do we store text in computer memory? We use coding schemes.
ASCII UNICODE
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Intro How do we store text in computer memory? We use coding schemes.
ASCII UNICODE
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128 Characters A = 65 7 Bits ASCII UNICODE
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128 Characters A = 65 ASCII 7 Bits UNICODE
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A = 65 ASCII 7 Bits 128 Characters UNICODE
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ASCII 7 Bits 128 Characters UNICODE A = 65
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? Error Checking other characters UNICODE ASCII 7 Bits 128 Characters A = 65
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? Error Checking other characters UNICODE ASCII 7 Bits 128 Characters A = 65
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A 65 B 66 C 67 a 97 b 98
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A 65 B 66 C 67 48 ERROR CHECKING a 97 b 98
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ASCII Characters 00110100 00111000 48 ERROR CHECKING 00000000 00110000
65 B 66 C 67 48 ERROR CHECKING a 97 b 98 Number -16 Bit Word
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ASCII Characters 00110100 00111000 52 56 ERROR CHECKING 4 8 48
65 B 66 C 67 ERROR CHECKING a 97 48 b 98 Number -16 Bit Word
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A 65 B 66 C 67 ERROR CHECKING 48 a 97 b 98
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ERROR CHECKING 00110100 00111000 Even Parity Total 1 Bits = even 48
65 B 66 Even Parity Total 1 Bits = even C 67 48 _ Odd Parity Total 0 Bits = odd a 97 b 98 _
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ERROR CHECKING 00110100 00111000 Majority Vote Even Parity
65 B 66 Majority Vote Even Parity Total 1 Bits = even C 67 48 _ a 97 Odd Parity Total 0 Bits = odd b 98 _
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Hamming code - transmitting
Bit Position 11 10 9 8 7 6 5 4 3 2 1 Date/Parity D P4 P3 P2 P1 Data Code Sent
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Hamming code - DECODING
Bit Position 11 10 9 8 7 6 5 4 3 2 1 Date/Parity D P4 P3 P2 P1 Code Flip Data
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