Data Representation




Specification Reference

  • understand that computers use the binary alphabet to represent all data and instructions
  • understand the terms bit, nibble, byte, kilobyte, megabyte, gigabyte and terabyte
  • understand that a binary code could represent different types of data such as text, image, sound, integer, date, real number
  • understand how binary can be used to represent positive whole numbers (up to 255)
  • understand how sound and bitmap images can be represented in binary
  • understand how characters are represented in binary and be familiar with ASCII and its limitations
  • understand why hexadecimal number representation is often used and know how to convert between binary, denary and hexadecimal


Supporting Resources

Binary

comp20binary

Learning Cycle Objectives:

  • Understand how computers count in binary
  • Be able to convert numbers up to 255 between denary (decimal) and binary

Resources

Textbook Ref:

  • binary data 144

Hexadecimal

comp20hexadecimal

Learning Cycle Objectives:

  • Know how the Hexadecimal counting system works
  • Be able to convert between denary, binary & hexadecimal counting systems

Resources

Images

computing images

Learning Cycle Objectives:

  • Understand the terms bitmap & pixel
  • Understand how bitmap images are stored using binary in a computer system
  • Understand the term metadata and what it is for (height, width, colour-depth)

Resources



Sound

flat sound banner

Learning Cycle Objectives:

  • Be able to explain how sound can be sampled and stored in digital form
  • Know how sampling intervals (and other considerations) affect the size and quality of a sound file

Resources

Textbook Ref:

  • sound data files 145–147
  • speakers 120

ASCII & Unicode

computing ascii

Learning Cycle Objectives:

  • Understand how Charatures are represented in binary
  • Be familiar with ASCII and it's limitations

Resources


Textbook Ref:

  • ASCII 145