Memory (RAM and ROM)

    OCR
    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.

    0
    Objectives
    3
    Exam Tips
    4
    Pitfalls
    4
    Key Terms
    5
    Mark Points

    What You Need to Demonstrate

    Key skills and knowledge for this topic

    • Award 1 mark for stating that RAM is volatile and loses contents when power is removed
    • Award 1 mark for identifying that ROM is non-volatile and stores the BIOS/bootstrap loader
    • Award 1 mark for explaining that RAM stores the operating system, applications, and data currently in use
    • Award 1 mark for describing Virtual Memory as a section of secondary storage used as temporary RAM when physical RAM is full
    • Award 1 mark for explaining that data is swapped or paged between RAM and Virtual Memory

    Marking Points

    Key points examiners look for in your answers

    • Award 1 mark for stating that RAM is volatile and loses contents when power is removed
    • Award 1 mark for identifying that ROM is non-volatile and stores the BIOS/bootstrap loader
    • Award 1 mark for explaining that RAM stores the operating system, applications, and data currently in use
    • Award 1 mark for describing Virtual Memory as a section of secondary storage used as temporary RAM when physical RAM is full
    • Award 1 mark for explaining that data is swapped or paged between RAM and Virtual Memory

    Examiner Tips

    Expert advice for maximising your marks

    • 💡When asked about the difference between RAM and ROM, always compare both volatility and purpose to ensure full marks
    • 💡In Virtual Memory questions, explicitly mention the movement of data: 'pages are moved from RAM to secondary storage' to free up space
    • 💡Use the specific term 'currently in use' when describing what RAM holds; omitting this phrase often results in lost marks for vague answers

    Common Mistakes

    Pitfalls to avoid in your exam answers

    • Stating that ROM stores 'memory' or 'files' rather than specifically the BIOS or bootstrap instructions
    • Confusing 'volatile' with 'unstable' or 'explosive'—candidates must use the term in the context of data retention upon power loss
    • Asserting that adding Virtual Memory improves performance speed; it actually prevents crashing but slows access speeds due to disk thrashing
    • Confusing Memory (RAM) with Storage (Hard Drive/SSD) when discussing where saved files reside

    Study Guide Available

    Comprehensive revision notes & examples

    Read Study Guide

    Key Terminology

    Essential terms to know

    Volatile (RAM) vs Non-volatile (ROM) characteristics
    Role of RAM in the Fetch-Decode-Execute cycle
    Function of ROM in system bootstrapping (BIOS)
    Virtual Memory mechanics and performance trade-offs

    Likely Command Words

    How questions on this topic are typically asked

    State
    Describe
    Explain
    Compare
    Discuss

    Ready to test yourself?

    Practice questions tailored to this topic