1. Phnom Penh International University (PPIU)
9/14/2018
សាកលវិទ្យាល័យភ្នំពេញអន្តរជាតិ
Phnom Penh International University
Quality Excellence Innovation o
Computer Literacy
Internal Use Only

2. Chapter 7
Data Processing

3. After this chapter, students would be able to: Data vs. Information
Objectives
After this chapter, students would be able to:
Data vs. Information
Computer represent data
File Processing Concept and Organization

4. The difference between Data and information
Data is/are the facts of the World
For example, take yourself. 
You may be 5ft tall, have brown hair and blue eyes.
All of this is “data”.
 You have brown hair whether this is written down somewhere or not.

5. The difference between Data and information
Information is data has been processed
Here is a simple analogy for you
If I take a picture of you, the photograph is information. But what you look like is data.
In Brief
Data: Facts, a description of the World
Information: Captured Data and Knowledge

6. HOW COMPUTERS REPRESENT DATA
to a computer numbers, letters, sounds, and pictures are all represented by zeros (0) and ones (1)
in a computer all data must be reduced to electrical switches
a switch has only two states - "ON" (1) and "OFF" (0)
the computer uses the binary numbering system

7. BIT and BYTE Bit - binary digit - smallest possible unit of data
Nibbles
A nibble is a collection of four bits
With a nibble, we can represent up to 16 distinct values.

8. BIT and BYTE Byte - group of 8 bits
- using various ON (1)/OFF(0) combinations 256 different values can be expressed
values from 0 to 255 represent uppercase letters, lowercase letters, numbers, punctuation, and other symbols

9. Text Codes
Early programmers realized that they needed a standard text code
Text is represented by number
The standard code system would enable any programmer or program to use the same combinations of number to represent the same individual pieces of data.

10. are three of the most popular text code systems invented.
ASCII
EBCDIC
Unicode
are three of the most popular text code systems invented.

11. ASCII
ANSI’s solution to representing symbols with bits of data was the ASCII character set
ACSII (pronounced AS-key) stands for American Standard Code for Information Interchange
ACSII an 8-bit code that specify characters up to only 127 and different characters sets for codes 128 through 255.

12. EBCDIC (Extended Binary Coded Decimal Information Code)
The BCD (binary coded decimal) system, defined by IBM for one of its early computers
Was one of the first complete systems to represent symbols with bits.
BCD codes consisted of 6-bit codes, which allowed a maximum of sixty-four possible symbols.
BCD computers could work only with uppercase letters and with very few other symbols

13. EBCDIC (Extended Binary Coded Decimal Information Code)
The need to represent more characters led to IBM’s development of the EBCDIC system
EBCDIC (Pronounced EB-si-dic) stand for Extended Binary Coded Decimal Information Code
EBCDIC is an 8-bit code that defines 255 symbols
By the time small computers were being developed, the American National Standards Institute (ANSI) had begun to define new text code standards for computers

14. ISO
The International Standard s Organization expanded on the ASCII character set,
To offer different sets of characters for different language group
this organization works to establish international standards and publish documents describing each technology, ISO covers Western European languages.

15. Unicode An evolving standard for data representation called Unicode
Worldwide Character Standard, provide 2 bytes-16 bits to represent each letter, number, or symbol
With 2 bytes, enough Unicode codes can be created more than 65,536 different characters or symbols
This total is enough for every unique character and symbol in the world

16. Unicode Including the vast Chinese, Korean, and Japanese
The Unicode standard was developed in 1991 by a joint engineering team from Apple Computer Corporation and Xerox Corporation

17. Character
Binary
Dec 48 1 49 2 50 3 51 4 52 5 53 6 54 7 55 8 56 9 57
Character
Binary
Dec a 97 b 98 c 99 d
100 e
101 f
102 g
103 h
104 i
105 j
106 k
107 l
108 m
109 n
110 o
111 p
112 q
113 r
114 s
115 t
116 u
117 v
118 w
119 x
120 y
121 z
122
Character
Binary
Dec A 65 B 66 C 67 D 68 E 69 F 70 G 71 H 72 I 73 J 74 K 75 L 76 M 77 N 78 O 79 P 80 Q 81 R 82 S 83 T 84 U 85 V 86 W 87 X 88 Y 89 Z 90

18. File Organization
A Folder, Directory, Catalog, or drawer, is a virtual container originally derived from which groups of computer files and other folders can be kept and organized.