1. Binary Numbers and ASCII and EDCDIC Mrs. Cueni

2. Data Representation  Human speech is analog because it uses continuous signals (waves) that vary in strength and quality  Computers are digital – recognize two states ones and zeros, on of off  0 and 1 is called a bit Binary Digit  Smallest unit of information

3. Data representation  8 bits grouped together called a byte  Represent 256 individual characters  Numbers, uppercase, lowercase letters, punctuation marks  Based 2 numbering system

4. Coding Scheme  Two popular coding schemes ASCII – American Standard Code for Information Interchange ASCII – American Standard Code for Information Interchange EBCDIC – Extended Binary Coded Decimal Interchange Code EBCDIC – Extended Binary Coded Decimal Interchange Code Sufficient for English and Western Europe languages Sufficient for English and Western Europe languages Not large enough for Asian and other languages Not large enough for Asian and other languages

5. Coding Sheet ASCII numbers  00110000 is the number zero  The first four bits 0011 – identify as a number  The last four digits 0000 determines the number 1286432168421 00110000

6. Binary numbering system  Base 10  4+2+1 = 7  Base 2 4+2+1 = 7 8+2 = 10 2727 2626 2525 2424 23232 2121 2020 1286432168421 00110111 00111010 10 7 10 6 10 5 10 4 10 3 10 2 10 1 10 0 100000001000000100000100001000100101 85680345 85,680,345

7. What are these numbers? 00110101 –

8. What are these numbers? 00110011 –

9. What are these numbers? 00111001 –

10. What are these numbers? 00110111 –

11. What are these numbers? 00110110 –

12. What are these numbers?  00111111

13. Coding Sheet ASCII letters  01000001 is the letter A  The first two bits 01 – identify as a letter  The last six digits 000001 determines the letter as the first letter in the alphabet A

14. How did you do that?  01011010 is the letter Z  The first two bits 01 – identify as a letter  The last digits 011010 = 16+8+2=26  26 th letter Z 1286432168421 01011010 16+8+2=26

15. Letter order  1 st – A  2 nd – B  3 rd – C  4 th – D  5 th – E  6 th – F  7 th - G  8 th – H  9 th - I  10 th – J  11 th – K  12 th – L  13 th - M  14 th – N  15 th - O  16 th - P  17 th – Q  18 th – R  19 th – S  20 th – T  21 st – U  22 nd - V  23 rd – W  24 th – X  25 th – Y  26 th  26 th - Z

16. What are these letters?  01000001  01010111  01001010  01010101

17. Coding Schemes  Make it possible to interact with computers  Does this very quickly without you realizing it  Type a character, the computer converts it and processes the data to something it understands  The software converts it back to something we understand

18. Unicode  Many languages use symbols called ideograms to represent multiple words or ideas  Unicode is a 16-bit code that has the capacity of representing more than 65,000 characters and symbols

19. Parity bit  Used by computers for error checking  Extremely rare  Computers are either odd- or even- parity  Total number of bits on must be even on even-parity computers or odd on odd- parity bit computers  9 bit pattern

20. Transferring data  When computers transfer data from one location to another it checks the sending data and the receiving data to make sure the parity bit is the same  An error is displayed if the parity doesn’t match

21. Hexadecimal  Used for communicating with programmers when a problem exists  0’s and 1’s can be difficult to read  Pass out Hexadecimal chart

22. Hexadecimal  Uses 16 symbols to represent values  Hex means six, deci means ten  Conversion between binary and hexadecimal is very efficient  The letter M is 01001101 in binary  In Hexadecimal 4D  Divide binary number into two sections 0100 and 1101  Convert each section to the hex equivalent 0100 is a 4 and 1101 is letter D  A=10, B=11, C=12, D=13, E=14, F=16

23. Data Storage video  Progressive Insurance video on data storage

24. Binary Conversion Sheet  Complete in class the binary conversion sheet  Worth 26 points  Sources http://www.computerhope.com/binhex.htm