Computer systems flashcards

Computer systems is a fundamental topic in GCSE Computer Science covering how hardware and software work together to process data. Students must understand the role of the CPU, including its components such as the ALU, control unit and registers, and how the fetch-decode-execute cycle operates. The topic also covers primary and secondary storage, including the differences between RAM, ROM, and various storage devices. Students need to understand how the operating system manages hardware resources and provides a platform for applications. Embedded systems, the purpose of different types of software, and how data is represented in binary are also key areas. Understanding how these components interact as a complete system, and being able to evaluate trade-offs such as speed versus cost in storage choices, is essential for exam success.

1. Card 1

   What is the role of the CPU in a computer system?

   The CPU (Central Processing Unit) carries out instructions from programs by fetching, decoding and executing them. It is the main component responsible for processing data.

2. Card 2

   What are the three main components inside a CPU?

   The ALU (Arithmetic Logic Unit) performs calculations and logical operations, the control unit manages instruction flow, and registers are small, fast storage locations within the CPU.

3. Card 3

   Describe the fetch-decode-execute cycle.

   The CPU fetches an instruction from memory, decodes it to understand what action is needed, then executes it. This cycle repeats continuously while the computer is running.

4. Card 4

   What is the difference between RAM and ROM?

   RAM (Random Access Memory) is volatile, meaning data is lost when power is removed. ROM (Read Only Memory) is non-volatile and stores permanent instructions such as the boot program.

5. Card 5

   What does 'volatile' mean in the context of storage?

   Volatile storage loses its data when the power supply is switched off. RAM is volatile, which is why unsaved work is lost during a power cut.

6. Card 6

   Name three factors that affect CPU performance.

   Clock speed (how many cycles per second), number of cores (allowing parallel processing), and cache size (fast memory close to the CPU) all influence how quickly a CPU can process instructions.

7. Card 7

   What is the purpose of cache memory?

   Cache is a small, very fast type of memory located close to the CPU. It stores frequently used instructions and data so the CPU can access them more quickly than fetching from RAM.

8. Card 8

   What is an embedded system?

   An embedded system is a computer built into another device to perform a dedicated function, such as the processor in a washing machine or a digital camera. It typically runs fixed software.

9. Card 9

   What is the difference between system software and application software?

   System software manages the hardware and provides a platform for other programs (e.g. an operating system). Application software performs tasks directly for the user, such as a word processor.

10. Card 10

    What are the main functions of an operating system?

    An operating system manages hardware resources, handles memory management, controls input and output devices, provides a user interface, and manages files and security.

11. Card 11

    What is secondary storage and why is it needed?

    Secondary storage is non-volatile storage used to keep data permanently, such as hard drives or SSDs. It is needed because RAM loses data when the computer is turned off.

12. Card 12

    What is a von Neumann architecture?

    Von Neumann architecture is the design principle where a computer stores both program instructions and data in the same memory. The CPU fetches and processes these using the fetch-decode-execute cycle.

• Many students confuse RAM with storage, incorrectly stating that a computer with more RAM can store more files permanently, when RAM only holds data temporarily while the computer is running.
• Students often mix up clock speed with the number of cores, assuming a higher clock speed always means better performance, without considering that multiple cores allow tasks to be processed in parallel.
• A common error is describing ROM as the place where all programs are stored, when in fact ROM only holds a small amount of permanent startup code, and programs are loaded into RAM during use.

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