1. ASCII and Unicode

2. Learning Outcomes

3. Terms

4. Outline ASCII Code Unicode system
Discuss the Unicode’s main objective within computer processing
Computer processing before development of Unicode
Unicode vs. ASCII
Different kinds of Unicode encodings
Significance of Unicode in the modern world

5. From Bit & Bytes to ASCII
Bytes can represent any collection of items using a “look-up table” approach
ASCII is used to represent characters
ASCII American Standard Code for Information Interchange

6. ASCII
It is an acronym for the American Standard Code for Information Interchange.
It is a standard seven-bit code that was first proposed by the American National Standards Institute or ANSI in 1963, and finalized in 1968 as ANSI Standard X3.4.
The purpose of ASCII was to provide a standard to code various symbols ( visible and invisible symbols)

7. ASCII
In the ASCII character set, each binary value between 0 and 127 represents a specific character.
Most computers extend the ASCII character set to use the full range of 256 characters available in a byte. The upper 128 characters handle special things like accented characters from common foreign languages.

8. In general, ASCII works by assigning standard numeric values to letters, numbers, punctuation marks and other characters such as control codes.
An uppercase "A," for example, is represented by the decimal number 65."

9. Bytes: ASCII
By looking at the ASCII table, you can clearly see a one-to-one correspondence between each character and the ASCII code used.
For example, 32 is the ASCII code for a space.
We could expand these decimal numbers out to binary numbers (so 32 = ), if we wanted to be technically correct -- that is how the computer really deals with things.

10. Bytes: ASCII
Computers store text documents, both on disk and in memory, using these ASCII codes.
For example, if you use Notepad in Windows XP/2000 to create a text file containing the words, "Four score and seven years ago," Notepad would use 1 byte of memory per character (including 1 byte for each space character between the words -- ASCII character 32).
When Notepad stores the sentence in a file on disk, the file will also contain 1 byte per character and per space.
Binary number is usually displayed as Hexadecimal to save display space.

11. Take a look at a file size now.
Take a look at the space of your p drive

12. Bytes: ASCII
If you were to look at the file as a computer looks at it, you would find that each byte contains not a letter but a number -- the number is the ASCII code corresponding to the character (see below). So on disk, the numbers for the file look like this:
F o u r a n d s e v e n

13. Externally, it appears that human beings will use natural languages symbols to communicate with computer.
But internally, computer will convert everything into binary data.
Then process all information in binary world.
Finally, computer will convert binary information to human understandable languages.

14. When you type the letter A, the hardware logic built into the keyboard automatically translates that character into the ASCII code 65, which is then sent to the computer. Similarly, when the computer sends the ASCII code 65 to the screen, the letter A appears.

15. ascii
ASCII stands for American Standard Code for Information Interchange
First published on October 6, 1960
ASCII is a type of binary data

16. Ascii part 2
ASCII is a character encoding scheme that encodes 128 different characters into 7 bit integers
Computers can only read numbers, so ASCII is a numerical representation of special characters
Ex: ‘%’ ‘!’ ‘?’

17. Ascii part 3 ASCII code assigns a number for each English character
Each letter is assigned a number from 0-127
Ex: An uppercase ‘m’ has the ASCII code of 77
By 2007, ASCII was the most commonly used character encoding program on the internet

18. (This is a funny picture)

19. Large files Large files can contain several megabytes
1,000,000 bytes are equivalent to one megabyte
Some applications on a computer may even take up several thousand megabytes of data

20. revisit “char” data type
In C, single characters are represented using the data type char, which is one of the most important scalar data types.
char achar;
achar=‘A’;
achar=65;

21. Character and integer
A character and an integer (actually a small integer spanning only 8 bits) are actually indistinguishable on their own. If you want to use it as a char, it will be a char, if you want to use it as an integer, it will be an integer, as long as you know how to use proper C++ statements to express your intentions.

22. General Understanding of the Unicode System

23. What is Unicode? A worldwide character-encoding standard
Its main objective is to enable a single, unique character set that is capable of supporting all characters from all scripts, as well as symbols, that are commonly utilized for computer processing throughout the globe
Fun fact: Unicode is capable of encoding about at least 1,110,000 characters!

24. Before Unicode Began…
During the 1960s, each letter or character was represented by a number assigned from multiple different encoding schemes used by the ASCII Code
Such schemes included code pages that held as many as 256 characters, with each character requiring about eight bits of storage!
Made it insufficient to manage character sets consisting of thousands of characters such as Chinese and Japanese characters
Basically, character encoding was very limited in how much it was capable of containing
Also did not enable character sets of various languages to integrate

25. The ASCII Code
Acronym for the American Standard Code for Information Interchange
A computer processing code that represents English characters as numbers, with each letter assigned a number from 0 to 127
For instance,  the ASCII code for uppercase M is 77
The standard ASCII character set uses just 7 bits for each character
Some larger character sets in ASCII code incorporate 8 bits, which allow 128 additional characters used to represent  non-English characters, graphics symbols, and mathematical symbols
ASCII vs Unicode

26. This compares what ASCII and Unicode are able to encode
This indicates how different characters are organized into representing a unique character set
This depicts how Unicode is capable of encoding characters from virtually every kind of language
This shows how Unicode can manipulate the style and size of each character
This compares what ASCII and Unicode are able to encode

27. Various Unicode Encodings
Name
UTF-8
UTF-16
UTF-16BE
UTF-16LE
UTF-32
UTF-32BE
UTF-32LE
Smallest code point
0000
Largest code point
10FFFF
Code unit size
8 bits
16 bits
32 bits
Byte order
N/A
<BOM>
big-endian
little-endian
Fewest bytes per character 1 2 4
Most bytes per character

28. Unicode’s Growth Over Time
This graph shows the number of defined code points in Unicode from its first release in 1991 to the present

29. ASCII vs Unicode -Has 128 code points, 0 through 127
-Can only encode characters in 7 bits
-Can only encode characters from the English language
-Has about 1,114,112 code positions
-Can encode characters in 16-bits and more
-Can encode characters from virtually all kinds of languages
-It is a superset of ASCII
-Both are character codes
-The 128 first code positions of Unicode mean the same as ASCII

30. Method of Encoding Unicode Transformation Format (UTF)
An algorithmic mapping from virtually every Unicode code point to a unique byte sequence
Each UTF is reversible, thus every UTF supports lossless round tripping: mapping from any Unicode coded character sequence S to a sequence of bytes and back will produce S again
Most texts in documents and webpages is encoded using some of the various UTF encodings
The conversions between all UTF encodings are algorithmically based, fast and lossless
Makes it easy to support data input or output in multiple formats, while using a particular UTF for internal storage or processing

31. Unicode Transformation Format Encodings
UTF-7
Uses 7 bits for each character. It was designed to represent ASCII characters in messages that required Unicode encoding
Not really used as often
UTF-8
The most popular type of Unicode encoding
It uses one byte for standard English letters and symbols, two bytes for additional Latin and Middle Eastern characters, and three bytes for Asian characters
Any additional characters can be represented using four bytes
UTF-8 is backwards compatible with ASCII, since the first 128 characters are mapped to the same values

32. UTF Encodings (Cont…) UTF-16 UTF-32 Makes it space inefficient
An extension of the "UCS-2" Unicode encoding, which uses at least two bytes to represent about 65,536 characters
Used by operating systems such as Java and Qualcomm BREW
UTF-32
A multi-byte encoding that represents each character with 4 bytes
Makes it space inefficient
Main use is in internal APIs where the data is single code points or glyphs, rather than strings of characters
Used on Unix systems sometimes for storage of information

33. What can Unicode be Used For?
Encode text for creation of passwords
Encode characters used in settings
Modify characters used in documents
Encodes characters to display in all webpages

34. Why is Unicode Important?
By providing a unique set for each character, this systemized standard creates a simple, yet efficient and faster way of handling tasks involving computer processing
Makes it possible for a single software product or a single website to be designed for multiple countries, platforms, and languages
Can reduce the cost over using legacy character sets
No need for re-engineering!
Unicode data can be utilized through a wide range of systems without the risk of data corruption
Unicode serves as a common point in the conversion of between other character encoding schemes
It is a superset of all of the other common character encoding schemes
Therefore, it is possible to convert from one encoding scheme to Unicode, and then from Unicode to the other encoding scheme.

35. Unicode in the Future…
Unicode may be capable of encoding characters from every language across the globe
Can become the most dominant and resourceful tool in encoding every kind of character and symbol
Integrates all kinds of character encoding schemes into its operations

36. Summary
Unicode’s ability to create a standard in which virtually every character is represented through its complicated operations has revolutionized the way computer processing is handled today. It has emerged as an effective tool for processing characters within computers, replacing old versions of character encodings, such as the ASCII. Unicode’s capacity has substantially grown since its development, and continues to expand on its capability of encoding all kinds of characters and symbols from every language across the globe. It will become a necessary component of the technological advances that we will inevitably continue to produce in the near future, potentially creating new ways of encoding characters.

37. Pop Quiz!
1. What is the main purpose of the Unicode system? -To enable a single, unique character set that is capable of supporting all characters from all scripts and symbols 2. How many code points is Unicode capable of encoding? -About 1,114,112 code points

38. References
Cavalleri, Beshar Bahjat & Igor. Unicode 101: An Introduction to the Unicode Standard Web <
Constable, Peter. Understanding Unicode Web <
"UTF." Teach Terms. N.p., 20 Apr Web. 13 Nov <http%3A%2F%2Fwww.techterms.com%2Fdefinition%2Futf>.
"UTF-8, UTF-16, UTF-32 & BOM." FAQ. N.p., n.d. Web. 13 Nov <