Little work is accurate Name: In this unit you will learn about: The difference between RAM and ROM. The purpose of ROM in a computer system. The purpose of RAM in a computer system. The need for virtual memory. Flash memory. Grade Target Depth Understanding Comment 7-9 All aspects complete All work is accurate 5-6 Most aspects complete Most work is accurate 3-4 Some aspects complete Some work is accurate 1-2 Little work complete Little work is accurate Response: Unit description and mark scheme.

Virtual tour of the inside of a computer Click here to return to the homepage Identify and label the key components: CPU, ROM, RAM, BIOS, and draw a thick bordered box around them. (It doesn’t matter if you are not sure, just use a component that looks about right!) Create a hyperlink from your label to the appropriate slide in this presentation. E.g. the link to ROM should be to slide 5. Credit: image from Jonathan Zander, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4994025

The CPU Name Purpose Components Factors affecting the speed Central processing unit Purpose To fetch and execute instructions. Components Arithmetic logic unit: performs calculations and logic. Control unit: decodes instructions and sends signals to control how data moves around the CPU. Cache: fast access memory for frequently used instructions and data. Registers: small fast memory used to help fetch and execute instructions. Factors affecting the speed Number of cores: independent processing units. Clock speed: The number of cycles per second. Cache: Temporary storage of instructions and data. There is nothing to do on this slide. It is here to show you the detail that is required in the next few slides.

RAM 3. Using the example shown on the ‘CPU’ slide as an example, draw a box around the component, and insert a text box to write your notes… 4. Use the following headings to explain this component: Name (write the full name of the component), Purpose, Volatile or Non-volatile (explain what this means), Read or Read/Write.

ROM 5. Draw a box around the component, and insert a text box to write your notes… 6. Use the following headings to explain this component: Name (write the full name of the component), Purpose, Volatile or Non-volatile (explain what this means), Read or Read/Write. 7. How else can ROM be used in computer systems? E.g. games cartridges. Include some examples.

Virtual memory Virtual memory is: Virtual memory is needed because: The problem with using virtual memory is that: 8. Complete the boxes to explain the purpose of virtual memory.

Stored programs on disk Example of virtual memory in use Hard disk Scenario: A user of a desktop PC has the operating system and presentation software open. Virtual memory on disk Stored programs on disk Operating System RAM 4Gb Word processor app Spreadsheet app Presentation app 0Gb 9. By copying the appropriate boxes from the hard disk into the memory, show how the memory is used in this scenario: a user has Windows and PowerPoint open. 10. Explain the problem of trying to put Photoshop in the memory space too. Graphics app If the user decides to open a graphics application to edit an image for the presentation too, the problem is that: Video editing app

Stored programs on disk Example of virtual memory in use Hard disk Scenario: A user of a desktop PC has the operating system, presentation and a graphics application open. The user is not currently working on the open presentation, just editing a photograph to include on a slide later. Virtual memory on disk Stored programs on disk Operating System RAM 4Gb Word processor app Spreadsheet app Presentation app 0Gb 11. Show how the problem can be resolved by using virtual memory. 12. Explain what has happened. Graphics app Explanation of the use of virtual memory in this scenario: Video editing app

Stored programs on disk Example of virtual memory in use Hard disk Scenario: The user switches back to the presentation software without closing the graphics application. Virtual memory on disk Stored programs on disk Operating System RAM 4Gb Word processor app Spreadsheet app Presentation app 0Gb 13. Explain and illustrate what happens when a program in virtual memory is needed again by the CPU. Graphics app Explanation of the use of virtual memory in this scenario: Video editing app

Stored programs on disk Why more RAM increases the speed of a computer Hard disk Scenario: The user doubles the amount of RAM in the computer to 8Gb, turns on the computer, opens the presentation app and the graphics app to continue working on the presentation. Virtual memory on disk Stored programs on disk Operating System RAM 4Gb Word processor app Spreadsheet app Presentation app 0Gb 14. Illustrate what happens if the user doubles the amount of RAM in the computer. 15. Explain why this makes the computer significantly faster. Graphics app Doubling the size of the RAM makes the computer faster because: Video editing app

Flash memory 16. Draw a box around the component, and insert a text box to write your notes… 17. Use the following headings to explain this component: Purpose (BIOS), Volatile or Non-volatile (explain what this means), Read or Read/Write. 18. Research other uses of flash memory in a computer system, and add these to this slide.