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Most people know that computer stores data in bit pattern using 1s and 0s.
But how can computer do this?

We'll look at integer first

Fixed Point Representation

• Sign-and-magnitude representation
  • The left most bit represents the sign of number
    ("0" stands for "+" while "1" stands for "-")
  • The remaining bit represent the binary equivalent of the magnitude of the number
• 2's complement representation

  Algorithm:

  • Convert the denary number to binary code
  • If it is +ve, you are finished, else conduct 3 & 4
  • Changing all 0s to 1s and all 1s to 0s
  • Add 1 to the result binary code.
• Excess code representation

  Algorithm (take 128 excess code as example):

  • Add 128 to the denary integer
  • Convert the result value to binary

Floating Point Representation

Floating Point Bit Pattern Divides in several parts

• Sign of mantissa ("1" = "-", "0" = "+")
• Magnitude of mantissa
• Exponent (can be represented by sign-snd-magnitude, 2's complement or excess code)

The sign of the number = Sign of mantissa
The value of the number = Magnitude of mantissa * 2 ^exponent