1. Representing Information as Bit Patterns
Chapter 1.4
Representing Information as Bit Patterns

2. Representing Information as Bit Patterns
Representing text
Representing Numeric Values
Representing Images
Representing Sound

3. Representing Text
Information in the form of text is normally represented by means of a code in which each of the different symbols in the text is assigned a unique bit pattern.
The text is then represented as a long string of bits in which the successive patterns represent the successive symbols in the original text.

4. Representing Text ASCII
American Standard Code for Information Interchange
Appendix A shows a portion of ASCII in an eight-bit-per-symbol format.

5. Representing Text

6. Representing Text Example: Message “Hello” in ASCII
H e l l o

7. Representing Text
Unicode, was developed through the cooperating of several of the leading manufacturers of hardware and software and is rapidly gaining support in the computing community.
It uses a unique pattern of 16 bits to represent each symbol.
It consists of 65,536 different bit patterns
Languages as Chinese, Japanese, and Hebrew can be represented.

8. Representing Text Question 1 on page 40
Here is a message encoded in ASCII using eight bits per symbol. What does it say?

9. Representing Text
Look it up in the ASCII Table

10. Representing Text

11. Representing Text
The answer is:
Computer Science.

12. Representing Numeric Values
Binary Notation
Fractions in Binary
Two’s Complement Notation
Negative values
Length of the Bit pattern
Excess notation
Length of the bit pattern

13. Representing Numeric Values
Floating-Point Notation
Different fields (sign, exponent, mantissa)
Sign bit
In the book, we only use 1 byte, which is 8 bits length
Where the radix point is

14. Representing Numeric Values
Floating-Point Notation
Extracting floating point
How to move the radix point
(+->R, - ->L)