Topic pathway
Memory and storage
Primary storage, secondary storage, units, compression, and data representation.
Exam-board information
CodeQuest is an independent learning platform. It is not endorsed by, affiliated with, or sponsored by OCR, AQA, Edexcel, Pearson, or any exam board. Exam board names and specification references are used only to identify relevant curriculum pathways.
Specification section
Primary Storage
RAM, ROM, cache, and volatile or non-volatile memory.
-
Lesson 01
RAM, ROM and Volatility
Describe the purpose and key characteristics of RAM and ROM.
-
Lesson 02
Virtual Memory and Performance
Explain why virtual memory is used.
-
Lesson 03
Primary Storage Scenarios
Analyse a system requirement involving primary storage.
Specification section
Secondary Storage
Magnetic, optical, and solid-state storage devices and suitability.
-
Lesson 01
Magnetic, Optical and Solid-State Storage
Distinguish magnetic, optical and solid-state secondary storage.
-
Lesson 02
Choosing Secondary Storage
Extract storage priorities from a scenario.
-
Lesson 03
Storage Characteristics
Define all six OCR storage characteristics.
-
Lesson 04
Primary vs Secondary Storage
Define primary storage.
Specification section
Units
Bits, bytes, storage units, conversions, and file size reasoning.
-
Lesson 01
Bits, Bytes and Binary Units
Define bit, nibble and byte and their relationships.
-
Lesson 02
Storage Unit Conversions
Convert between adjacent and multiple storage units.
Specification section
Data Storage
Binary, denary, hexadecimal, binary arithmetic, shifts, and data representation.
-
Lesson 01
Binary Addition
Recall the result and carry produced by adding binary digits.
-
Lesson 02
Character Sets
Explain why characters require a shared character set.
-
Lesson 03
Characters and Character Sets
Apply character-set mappings to complete messages.
-
Lesson 04
Images: Pixels, Colour Depth and Metadata
Explain how a grid of pixels represents a bitmap image.
-
Lesson 05
Sound: Sample Rate and Bit Depth
Explain how an analogue sound wave is sampled and stored in binary.
-
Lesson 06
Data Storage Calculations
Calculate the uncompressed size of a bitmap image.
-
Lesson 07
Binary, Denary and Hexadecimal
Explain why computers use binary.
-
Lesson 08
Hexadecimal and Binary Shifts
Explain why hexadecimal is used to represent binary data more compactly.
-
Lesson 09
Characters, Images and Sound
Explain what a character set is.
Specification section
Compression
Lossy and lossless compression, file size reduction, quality trade-offs, and suitable use cases.
-
Lesson 01
Choosing Compression Methods
Explain why data compression is used.
-
Lesson 02
Lossy and Lossless Compression
Explain why compression is used.