The document discusses information coding schemes used in data processing. It explains three common coding schemes - ASCII, EBCDIC, and Unicode. ASCII uses 8 bits to represent 256 characters and is used on personal computers. EBCDIC also uses 8 bits but is used on IBM mainframes. Unicode uses 16 bits to represent over 65,000 characters and supports all global languages.

1. 1
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Everyone thinks of changing the
world,
But NO one thinks of changing
himself…..

2. 2.3 Information Coding Schemes
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Topic 2

3.  Identify the coding system used in data processing:
• ASCII
• EBCDIC
• Unicode
 Differentiate the coding system.
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4. 4
 How computers represent data?
 Data & instructions can be represented
electronically by using bits and bytes
 Data representation refers to the form in which
data is stored, processed, and transmitted in
computers.
 Digital data is text, numbers, graphics, sound,
and video that has been converted into bit
patterns of 0s and 1s called binary numbers.
Data Representation-Review

5. Representing Numbers
5
Computers
represent all
numeric data
(numbers) with
the binary
system.
Number Binary
Representation
0 0 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 1
2 0 0 0 0 0 0 1 0
3 0 0 0 0 0 0 11
4 0 0 0 0 0 1 0 0
5 0 0 0 0 0 1 0 1
… …
254 1111111 0
255 11111111

6. Representing Text
(Character Set)
6
How can a
computer
represents non-
numeric
characters
(character
data )?
(such as what you
are reading now)
Answer:
Information
Coding
Schemes

7. What is Coding System?
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A coding system is the
patterns of 0s and 1s
combinations used to
represent characters.
Coding
Systems

8.  ASCII
[American Standard Code for Information Interchange]
 EBCDIC
[Extended Binary Coded Decimal Interchange Code]
 Unicode
[Uniform code capable of representing all world’s
languages]
Coding Systems

9. 9

10.  ASCII (pronounced “ask-ee”) is most widely used
coding scheme to represent data.
 ASCII uses 8 bits that represents a total of 256 (28 =
256) different characters.
 It is used in minicomputers, personal computers and
computers that make information available on the
Internet.
ASCII

11. 11
Part of ASCII Coding Scheme

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 Phrase Pay $8! written in ASCII Code
P a y space $ 8 !
01010000 01100001 01111001 00100000 00100100 00111000 00100001
Encoding means converting data into a digital form
Example of Encoding in
ASCII

13. EBCDIC
 EBCDIC (pronounced “ ebb-see-dic”) is a coding
scheme used by IBM mainframe computers and some
IBM midrange systems and high end servers.
 EBCDIC uses 8 bits and represents 256 (28 = 256)
different characters.
 EBCDIC is widely considered to be an obsolete coding
system, but is still used in some equipment, mainly in
order to allow for continued use of software written
many years ago that expects an EBCDIC
communication environment.

15. 15
 The 256 characters and symbols that are represented by
ASCII and EBCDIC codes are sufficient for English and
Westerns European languages.
 But they are not large enough for Asian and other
languages that use different alphabets .
 e.g: Eastern languages and historic symbols
Disadvantage of ASCII and
EBCDIC

16. UNICODE
 Today, computers make international communication
and business transactions possible, with a new coding
system named Unicode.
 Unicode uses 16 bits and represent 65, 536 (216 =
65,536) different characters, and can symbolize all the
world’s written languages.
 Unicode is implemented in several operating systems
including Windows, Mac OS, and Linux.

17. 17

18. 18

19. 19
Characteristic ASCII EBCDIC Unicode
Number of bits Uses 8 bits to
represent a
character
Uses 8 bits to
represent a
character
Uses 16 bits to
represent a
character
Number of
characters
Represent 256
characters
(28 = 256)
Represent 256
characters
(28 = 256)
Represent 65,536
characters
(216 = 65,536)
Usage Primarily used on
minicomputers,
personal computers
and server
Primarily used on
IBM mainframe,
midrange systems
and high-end
servers
Implemented in
several OS
(Windows, Mac
OS X, Linux)
Characteristic(s) of the Coding
Systems

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Advantages of ASCII & Unicode
 Advantage of using ASCII :
• ASCII uses 8 bits to represent a character,
meaning that storing data in ASCII takes up less
memory.
 Advantage of using Unicode :
• Unicode represent 65,536 characters, (216 =
65,536) that includes world’s current languages,
classical and historical languages and symbols.

21. Characteristic ASCII EBCDIC Unicode
Number of bits Uses 8 bits to
represent a
character
Uses 8 bits to
represent a
character
Uses 16 bits to
represent a
character
Number of
characters
Represent 256
characters
(28 = 256)
Represent 256
characters
(28 = 256)
Represent 65,536
characters
(216 = 65,536)
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Differences of the Coding
Systems

22. 22
Character
Coding Systems
ASCII EBCDIC Unicode
A 01000001 11000001 0000000001000001
B 01000010 11000010 0000000001000010
E 01000101 110000101 0000000001000101
Example of Encoding in the
Coding Systems

23. HELLO WORLD!
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Number of bits used by coding
system to represent phrase
H E L L O W O R L D !
1 2 3 4 5 6 7 8 9 10 11 12
ASCII EBCDIC UNICODE
12 characters x 8
bits = 96 bits
12 characters x 8
bits = 96 bits
12 characters x 16
bits = 192 bits

24. “Selamat datang ke KMS…”
….I LOVE MY FAMILY.…
“My name is Tom.”
‘A’ for Computer Science!!!
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ASCII / EBCDIC = 26 characters x 8 bits = 208 bits
UNICODE = 26 characters x 16 bits = 416 bits
ASCII / EBCDIC = 24 characters x 8 bits = 192 bits
UNICODE = 24 characters x 16 bits = 384 bits
ASCII / EBCDIC = 17 characters x 8 bits = 136 bits
UNICODE = 17 characters x 16 bits = 272 bits
ASCII / EBCDIC = 27 characters x 8 bits = 216 bits
UNICODE = 27 characters x 16 bits = 432 bits

25. 25
 When discussing numbers and alphabetical
characters, it is important to remember that all data
being transmitted through a computer system is
represented by bits or circuit notation.
 A fingerprint, picture, or company logo is also
converted by appropriate programs into patterns of
binary digits.
 Now that you understand bits, bytes, and
how computers represent data, it is
important to understand their relationship
to the rest of the system.
Conclusion

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1. How computer presents data?
2. Define Coding System/Scheme.
3. List three coding systems.
4. Explain ASCII from the number of bits, number of characters it
represents and the usage.
5. Explain EBCDIC from the number of bits, number of characters it
represents and the usage.
6. State the type of computer that still uses EBCDIC.
7. Explain Unicode from the number of bits, number of characters it
represents and the usage.
8. Discuss the advantage of using Unicode.
9. Discuss the advantage of using ASCII.
10. Explain why Unicode is becoming popular compared to ASCII and
EBCDIC.
11. Differentiate between ASCII, EBCDIC and Unicode from the
number of bits and number of characters.

27. 27
1. How many bits would it take to represent the following
phrase using the ASCII code?
Introduction to Computer Science
2. Give the benefit of using ASCII.
3. Give the benefit of using Unicode over ASCII.
4. How many different characters can Unicode
represent?
5. How many different characters can ASCII represent?
6. You are designing a computer system for use
worldwide, which character encoding scheme should
you use and why?
Discussion

28. 2. Complete the table below. State X.
28
Decimal Binary Hexa
65 1000001 X
50 X 32
69 1000101 X
Discussion

29. 1. What is the smallest unit of information a computer
can work with?
A. Megabyte C. Byte
B. Kilobyte D. Bit
2. Which of the following is listed in order from largest to
smallest
A. MB, GB, TB, KB C. TB, GB, MB,
KB
B. GB, MB, TB, KB D. KB, MB, GB,
TB
3. Which of the following is an example of a binary
number?
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30. 4. A character coding system that uses eight bits and can
represent 256 characters. ____________________
5. The numbering system uses the digits 0 through 9 and
the characters A through F. __________________
6. This is a system that attempts to imitate the behavior of
he human brain. ____________________
7. People refer to the series of input, process, output, and
storage activities of a computer as the
_____________________________________________
_.
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31. 8. ________ is any data and instructions entered into the
memory of a computer.
9. Which of the following types of computers typically has
the most expensive price range?
A. Mainframe B. Smart phone
C. Personal computer D. Mobile computer
10. Computers process data into
____________________.
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32. 11. Which of the following types of computers typically has
the lowest number of simultaneously connected users?
A. Game console B. Embedded computer
C. Supercomputer D. Tablet PC
12. Industries use ____________________ to shorten a
product’s time to market, reduce product
development costs, and stay ahead of the
competition.
13. Two types of ____________________ are desktop
computers and notebook computers.
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