Limitations of Binary (Edexcel GCSE Computer Science)

Limitations of Binary

What are the limitations of binary?

• Binary representation is constrained by the number of available bits, for example, the number of available bits determines how the following are represented:

  • Characters

  • Images

  • Sound

• The more bits, the greater range of unique values

• The amount of unique values can be calculated with the formula 2^{number of bits}, where 2 is the number base

Characters

• The number of bits limits the amount of available characters that can be represented

• For example, using 5 bits would allow 32 unique characters to be represented which is not enough to handle the English language (26 x lowercase, 26 uppercase letters etc.)

Images

• Modern computers use a minimum of 24 bits to represent high quality bitmap images

• Three groups of 8 bits are used to represent the amount of red, green & blue in each pixel (RGB)

• 24 bits = 16,777,216 unique colours

• Lowering the amount of available bits would reduce the unique colours, reducing the overall quality of the image

Sound

• CD has long been accepted as the standard for music quality, requiring 16 bits to be achieved (2¹⁶ = 65,536)

• Lowering the amount of available bits, for example in telephone calls reduces the quality of the sound (2⁸ = 256)

• This reduction is most evident in hold music used in telephone calls