IGCSE Computing - Data Representation

Binary
1. Written as 1's and 0's only
2. Directly controlls computers-all commands end up as binary
  1. All data ends up as binary
Denary
1. Standard number system
2. Written using numbers from 0 to 9
Hexadecimal
1. Written using 0 - 9 and A-F
  1. A,B,C,D,E and F represent 10-15
2. Used by computer programmers as a more user-friendly form of binary
  1. Each hexadecimal number represents four binary numbers, also known as 'nibbles'
Images
1. Two types of image storage- vector and bitmaps
  1. Vector
    1. Stores shapes of colour as a mathematical formula
    2. Useful for storing images with large sections of the same colour
    3. As a vector image is magnified, the detail increases due to the mathematical formulae used to create the image
  2. Bitmap
    1. Stores each pixel as a binary representation of a colour
    2. Useful for storing very detailed images consisting of small sections of many different colours
    3. As a bitmap image is magnified, it becomes pixelated
Sound
1. Sound represented as binary
  1. The more bits assigned to the data, the better the quality
Files
1. Data stored as binary
  1. ASCII codes are used to represent letters, numbers, symbols etc. as binary.
    1. Unicode is used to represent special characters not represented in ASCII
      1. ASCII uses 7-bit binary, Unicode uses 32-bit, giving it a much wider range of symbols possible to represent
Compression
1. Stores the data in as compact a form as possible
2. Different methods

Resource summary

	Created by Robin Skailes over 6 years ago