Memory (RAM and ROM)

    AQA
    GCSE

    Primary memory serves as the directly addressable workspace for the Central Processing Unit (CPU), critical for the Von Neumann architecture. Random Access Memory (RAM) is volatile, read-write storage that holds the Operating System, active applications, and data currently in use to facilitate the fetch-decode-execute cycle. Read Only Memory (ROM) is non-volatile and contains the bootstrap loader or BIOS required to initialize system hardware. Candidates must analyse the necessity of Virtual Memory when physical RAM is depleted, acknowledging the significant performance penalty caused by data swapping (thrashing) to secondary storage.

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    Objectives
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    Exam Tips
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    Pitfalls
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    Key Terms
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    Mark Points

    What You Need to Demonstrate

    Key skills and knowledge for this topic

    • Award 1 mark for stating that RAM is volatile (data is lost when power is removed) whereas ROM is non-volatile.
    • Award 1 mark for identifying that RAM holds the operating system, programs, and data currently in use by the CPU.
    • Award 1 mark for stating that ROM stores the boot sequence, bootstrap loader, or BIOS (Basic Input Output System).
    • Credit responses that explain RAM is read/write allowing instructions to be modified, whereas ROM is read-only.
    • Award 1 mark for linking insufficient RAM to the use of virtual memory, which slows system performance due to disk swapping.

    Marking Points

    Key points examiners look for in your answers

    • Award 1 mark for stating that RAM is volatile (data is lost when power is removed) whereas ROM is non-volatile.
    • Award 1 mark for identifying that RAM holds the operating system, programs, and data currently in use by the CPU.
    • Award 1 mark for stating that ROM stores the boot sequence, bootstrap loader, or BIOS (Basic Input Output System).
    • Credit responses that explain RAM is read/write allowing instructions to be modified, whereas ROM is read-only.
    • Award 1 mark for linking insufficient RAM to the use of virtual memory, which slows system performance due to disk swapping.

    Examiner Tips

    Expert advice for maximising your marks

    • 💡Always use the specific terms 'volatile' and 'non-volatile' instead of colloquial phrases like 'forgets data' or 'keeps data'.
    • 💡When justifying why a computer needs more RAM, explicitly mention 'reducing the need for virtual memory' to secure AO2 application marks.
    • 💡In comparison questions, structure your answer to contrast volatility, content (current programs vs. BIOS), and editability (Read/Write vs. Read-Only) side-by-side.

    Common Mistakes

    Pitfalls to avoid in your exam answers

    • Stating that the entire Operating System is stored in ROM (it is stored in secondary storage and loaded into RAM upon boot).
    • Confusing 'memory' (RAM) with 'secondary storage' (HDD/SSD), incorrectly implying that files saved in RAM are permanent.
    • Asserting that adding more RAM increases the processing speed (clock speed) of the CPU, rather than explaining it reduces reliance on slower virtual memory.
    • Describing ROM as 'random access' simply because it is memory; candidates must treat it as distinct from RAM in terms of access capability.

    Key Terminology

    Essential terms to know

    Likely Command Words

    How questions on this topic are typically asked

    State
    Explain
    Compare
    Describe
    Justify

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