1. Information and Programs

2. Foundations of Computing Information –Binary numbers –Integers and Floating Point –Booleans (True, False) –Characters –Variables Programs –Expressions –Assignment –Sequences

3. Information  Binary numbers Integers and Floating Point Booleans (True, False) Characters Variables

4. Decimal Numbers Each digit is a power of ten 12345 = 5 * 1 + 4 * 10 + 3 * 100 + 2 * 1000 + 1 * 10,000

5. Binary Numbers Each Digit is a power of two 10110 = 1 * 0 + 2 * 1 + 4 * 1 + 8 * 0 + 16 * 1 = 22

6. Binary Numbers Each Digit is a power of two 1011101 = = 93 1 * 1 + 2 * 0 + 4 * 1 + 8 * 1 + 16 * 1+ 32 * 0 + 64 * 1

7. Why Binary? Any physical phenomenon that has two states can be used to store a binary number 11010= 26

8. Magnetism + - + - + + Magnetic Material Read/Write Head 1 101011 = 43

9. Voltage +5 000 100101= 37

10. Holes in Paper Light = 1 Dark = 0 101010 = 42 Photo Sensor Light

11. Binary Students Male = 0 Female = 1

12. Why Binary? Any physical phenomenon that has two states can be used to store a binary number Each binary digit is called a BIT –1010 - is a 4 bit number –01010100 - is an 8 bit number An 8 bit number is called a BYTE

13. Size of a Binary Number How many different numbers can you store in 2 bits? How many can you store in 8 bits? In general, 2 (number of bits) numbers can be stored How many in 10 bits? –1024 = 1K How many in 20 bits? –1,048,576 = 1Meg

14. Information Binary numbers  Integers and Floating Point Booleans (True, False) Characters Variables

15. Integers 100 100245 -45

16. Size of an Integer How many bits required for the number 17? 5 bits How many bits for the number 1023? 10 bits

17. Integer Expressions * means multiply / means divide 2*4+3 = 11 2*(4+3) = 14 (7+9)/2 = 8

18. Floating point numbers Numbers with decimal points 1.23 5623.1232 -0.00232

19. Floating point numbers Numbers with decimal points 1.23 = 0.123e1 5623.1232 = 0.56231232e4 -0.00232=-0.232e-2 Stored differently (sign + fraction + exponent)

20. Information Binary numbers Integers and Floating Point  Booleans (True, False) Characters Variables

21. Booleans 1 = true 0 = false

22. Boolean Expressions (7>3) is true ((2+4)<6) is false > Greater than < less than <= less than or equal >= greater than or equal == equal != not equal 7<=6 is false 6!=5 is true

23. Information Binary numbers Integers and Floating Point Booleans (True, False)  Characters Variables

24. ASCII Code for Characters Every character is defined to have an 8 bit (1 byte) number What is special about the order of the numbers? Type ‘g’ Store 103

25. ASCII Code for Characters A numeric character is different from its ASCII number

26. ASCII Code for Characters Dad32@Abc 68 97 100 51 50 64 65 98 99

27. What about Chinese, Sanscrit, Hebrew, Cyrillic, etc ??

28. UNICODE rather than ASCII 2 Bytes per character –Twice as much space –65,536 possible characters (2^16)

29. Expressions with characters ‘A’ + 2 = ‘C’ ‘g’- ‘d’ = 3 ‘F’ + 32 = ‘f’ ‘A’ < ‘D’ is true ‘%’ >= ‘+’ is false

30. Information Binary numbers Integers and Floating Point Booleans (True, False) Characters  Variables

31. Variable A named place to store a value –George = 32 –Size = 17 –Weight = 120

32. Program A sequence of things to do A = 75; B = A+13; A = A-B+3; C = A/2 + 1;

33. Program A sequence of things to do A = 75; B = A+13; A = A-B+3; C = A/2 + 1;

34. Program A sequence of things to do A = 75; B = A+13; A = A-B+3; C = A/2 + 1; A + 13 75 + 13 = 88

35. Program A sequence of things to do A = 75; B = A+13; A = A-B+3; C = A/2 + 1; A-B+3 75 - 88 + 3 = -10

36. Program A sequence of things to do A = 75; B = A+13; A = A-B+3; C = A/2 + 1; A / 2 + 1 -10 / 2 + 1 = -4

37. Review Binary numbers (using any two states) Integers and Floating Point –Expressions (+ - * /) Booleans (true, false) ( = == !=) Characters –ASCII, UNICODE Variables Programs