1 / 26

1.4 + 1.5

1.4 + 1.5. Representing text. Each of different symbol on the text (alphabet letter) is assigned a unique bit patterns the text is then representing as a long string of bits.

kira
Download Presentation

1.4 + 1.5

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 1.4 + 1.5

  2. Representing text • Each of different symbol on the text (alphabet letter) is assigned a unique bit patterns • the text is then representing as a long string of bits. • ASCII” American standard code for information interchange”: Uses patterns of 7-bits to represent most symbols used in written English text. • Today, it is extended to 8-bits. Islamic University Of Gaza, Nael Aburas 2

  3. Figure 1.13 The message “Hello.” in ASCII Islamic University Of Gaza, Nael Aburas 3

  4. Representing Text: The American National Standards Institute (ANSI) adapted the American Standard Code for Information Interchange (ASCII) This code uses 7 bits to represent the alphabets (a-z & A-Z) and numbers from 0 to 9 and punctuation symbols.

  5. Unicode: This code uses 16 bits represents each symbols. Unicode consists of 65536 different bit patterns enough to allow text written in such languages A file containing a long sequence of symbols encoded using ASCII or Unicode is often called a text file

  6. Representing text • Unicode: Uses patterns of 16-bits to represent the major symbols used in languages world side • ISO standard: Uses patterns of 32-bits to represent most symbols used in languages world wide Islamic University Of Gaza, Nael Aburas 6

  7. The difference between word processors and text file as follows:

  8. Representing Numeric Values Binary notation is a way of representing numeric values using only digits 0 and 1. Islamic University Of Gaza, Nael Aburas 8

  9. Representing Numeric Values A number can be represented differently in different systems. For example, the two numbers (2A)16 and (52)8 both refer to the same quantity, (42)10, but their representations are different. Each number system is associated with a base Islamic University Of Gaza, Nael Aburas 9

  10. Representing Numeric Values Integer Fraction A number represented as: Each digit carries a certain weight based on its position Islamic University Of Gaza, Nael Aburas 10

  11. Binary system In the binary system, there are only two symbols or possible digit values, 0 and 1. This base-2 system can be used to represent any quantity that can be represented in decimal or other number system Islamic University Of Gaza, Nael Aburas 11

  12. Binary system • For example, here is (11001)2 in binary • (101.11)2 Islamic University Of Gaza, Nael Aburas 12

  13. Decimal The decimal system is composed of 10 numerals or symbols. These 10 symbols are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9; using these symbols as digits of a number, we can express any quantity. The decimal system, also called the base-10 system Islamic University Of Gaza, Nael Aburas 13

  14. Decimal system • (224)10 • Note that the digit 2 in position 1 has the value 20, but the same digit in position 2 has the value 200 Islamic University Of Gaza, Nael Aburas 14

  15. Figure 1.15 The base ten and binary systems Islamic University Of Gaza, Nael Aburas 15

  16. Figure 1.16 Decoding the binary representation 100101 Islamic University Of Gaza, Nael Aburas 16

  17. Exercise • Convert each of the following binary representation to its base ten: • 0101 • 1001 • 1011 • 0110 • 1000 • 10010 Islamic University Of Gaza, Nael Aburas 17

  18. Figure 1.17 An algorithm for finding the binary representation of a positive integer Islamic University Of Gaza, Nael Aburas 18

  19. Figure 1.18 Applying the algorithm in Figure 1.15 to obtain the binary representation of thirteen Islamic University Of Gaza, Nael Aburas 19

  20. Binary addition To add two integers represented in binary notation, we follow the same procedure in the traditional base ten except that all sums are computed using the following addition fact. Islamic University Of Gaza, Nael Aburas 20

  21. Binary addition Islamic University Of Gaza, Nael Aburas 21

  22. Binary addition Islamic University Of Gaza, Nael Aburas 22

  23. Binary addition Islamic University Of Gaza, Nael Aburas 23

  24. Fraction in binary The digit to the right of radix point represent the fractional part. The positions are assigned fractional quantities The first position is assigned the quantity ½ (which is 2-1), and so on Islamic University Of Gaza, Nael Aburas 24

  25. Fraction in binary Islamic University Of Gaza, Nael Aburas 25

  26. Decimal fraction to binary • Covert 0.625 to base 2 625 x 2 = 1.25 .625 = .1 25 x 2 = 0.50 .625 = .10 .50 x 2 = 1.00 .625 = .101 Islamic University Of Gaza, Nael Aburas 26

More Related