Data Coding and Information Decoding

Educational level: this is a secondary education resource.

Resource type: this resource is a lesson.

Completion status: this resource is ~75% complete.

This is a lesson in the course Introduction to Computers, which is a part of The School of Computer Science

Introduction to Computers
What is a computer? Hardware Numeral systems Data sizes and speeds Data Coding and Information Decoding Types of computers Computer networks Software References

Unique Code

Data are Numbers, Text, Sounds, Image, Animation, Video, etc.; in order to define them in the real world, we are using Numbers (0,...9), an Alphabet (A,...Z) and symbols (@,[,\,...) or a combination of them, for example:

• 2012 ( Number )
• Wikiversity ( Alphabet )
• 3<5 ( combination of Number and symbol )
• X=(Y*Z)+W-U ( combination of Alphabet and symbols )
• N123 ( combination of Alphabet and Number )

Computers, however, don't understand the definitions for Numbers (0,...9), the Alphabet (A,...Z) and symbols (@,[,\,...), so in order to process those pieces of information a unique code must be assigned to each of them. The unique code for Numbers (0,...9), the Alphabet (A,...Z) and symbols (@,[,\,...) is a binary numeral.

show 1,0 in binary numbers

In practical use, each "0" and "1" in binary number uses a Physical attribute that is electrical or magnetic. The smallest part of that Physical attribute is named "Bit", the existence of the Physical attribute is "1", and the absence of the Physical attribute is "0"; 8-bit grouped up are called 1 Byte (so 1 byte=8 bit).

The binary numeral system, or base-2 number system, represents numeric values using two symbols - 0 and 1.

Examples:

• numerical value " 0 " is 0. The unique code for 0 is → 00000000
• numerical value " 1 " is 1. The unique code for 1 is → 00000001
• numerical value " 2 " is 10. The unique code for 2 is → 00000010
• numerical value " 3 " is 11. The unique code for 3 is → 00000011
• numerical value " 4 " is 100. The unique code for 4 is → 00000100
• numerical value " 5 " is 101. The unique code for 5 is → 00000101
• numerical value " 6 " is 110. The unique code for 6 is → 00000110
• numerical value " 7 " is 111. The unique code for 7 is → 00000111
• numerical value " 8 " is 1000. The unique code for 8 is → 00001000
• numerical value " 9 " is 1001. The unique code for 9 is → 00001001

Alphabet (A,...Z):

• The unique code for " A " is → 01000001
• The unique code for " B " is → 01000010
• The unique code for " C " is → 01000011
• .....
• .....
• .....
• The unique code for " Z " is → 01011010

for symbols ():

• The unique code for " @ " is → 01000000
• The unique code for " [ " is → 01011011
• The unique code for " \ " is → 01011100
• .....
• .....
• .....

File:Pals2.png

show number 10101010

Distinction between "Data" and "Information"