Edexcel GCSE Computer Science (1CP2) Exam Questions

• B Incremental (1)
• The only correct answer is B. The correct answer is incremental.
• A is not correct because a full backup copies all of the data on a disk
• C is not correct because an off-site backup is stored in a different location
• D is not correct because a scheduled backup runs at set times

Award one mark for:

• Folder (1)

Allow directory/subfolder/subdirectory.

Do not accept file.

Do not accept file system/partition/file tree/directory structure.

Award one mark for any of the following up to a maximum of two marks:

• Deciding which process runs next on the CPU/scheduling processes (1)
• Allocating processor/CPU time to processes/allowing multitasking (1)
• Managing the process life-cycle/process states (ready, running, blocked) (1)
• Handling interrupts so a running process is suspended and another can run (1)
• Stopping/terminating a process when it has finished (1)

Do not accept 'managing processes' on its own.

Do not accept 'handling interrupts' on its own.

Do not award two marks for the same task expressed twice, e.g. 'deciding which process runs next' and 'scheduling processes', or 'allocating CPU time' and 'giving each process a share of processor time'.

Do not accept 'managing memory/memory management', 'managing files/file management' or 'managing devices/peripherals' (these are other functions of an operating system).

Award up to two marks for a linked description such as:

• Keeps a record/index of where each file is stored on the disk (1) so that the file can be found and opened when it is needed (1)
• Allocates each file to a folder/directory (1) so that files used for the same purpose are kept together (1)
• Decides where on the disk each new file is written (1) so that it does not overwrite an existing file (1)
• Allocates space on the disk for a file (1) so that the file has somewhere to be saved (1)

Allow 'files are organised into folders so that they are easy to find', with the folder point (1) and its purpose (1).

Do not accept responses that only state that the operating system 'organises' or 'controls' the files, with no way of doing it given.

Do not accept 'stores the files' or 'saves files to the disk' without a way of doing it.

Do not accept responses about backing files up, or about the amount of storage space left on the disk.

Award up to two marks for a linked explanation such as:

• The file can be found/opened later (1) because the operating system uses the stored location/address to access it (1)
• The file can be updated/saved again (1) because the operating system knows where to write the new data on the disk (1)
• A new file does not overwrite an existing file (1) because the operating system knows which parts of the disk already hold data (1)

For both marks, the expansion must follow/associate with the statement.

Do not accept 'so the file is saved' on its own without a reason linked to finding/using the file later.

Do not accept 'to organise files' without expansion as to how the record helps the operating system find a file.

Do not accept 'so the operating system knows where the file is' without saying that this record is used to find/access/update the file.

Award up to two marks for a linked explanation such as:

• Files can be organised into folders/directories (1) so users can find/store files easily (1)
• Files can be located/opened/saved (1) because the operating system keeps track of where each file is stored (1)
• Access permissions can be set on files (1) so only allowed users can read/modify them (1)
• Files can be copied/moved/deleted (1) because the operating system controls where data is written/removed on a storage device (1)
• Free disk space can be monitored/managed (1) so storage does not run out / files are stored efficiently (1)

For both marks, the expansion must follow/associate with the statement.

Do not accept 'manages files' or 'organises files' on its own as it repeats the question.

Allow 'makes it easier to find files' as the linked reason for organising files into folders.

Award up to two marks for a linked explanation such as:

• The installation may cause the computer/system to fail/stop working/crash (1) so the computer/system can be restored to its previous state/setup (1)
• The installation may damage/corrupt/delete existing files/data (1) so the files/data can be recovered/restored from the backup (1)
• The new software/program may not be compatible with the existing system/software (1) so the user can return to the previous working version/setup (1)
• The new software/installation may contain malware/a virus (1) so files/data damaged/deleted by the malware can be restored from the backup (1)

For both marks, the expansion must follow/associate with the statement.

Allow 'recover from a failed installation' as the point and 'restore the previous system/setup' as the linked reason.

Do not accept 'so the files are safe' / 'in case something goes wrong' / 'to keep a copy of the files' on its own without naming what could go wrong and how the backup helps.

Do not accept 'the backup will be safe' as the linked reason; it does not say how the backup helps.

Do not accept 'to free up storage' or 'to make the computer faster' as these are not reasons for backing up.

Indicative content

What a device driver is and how the operating system uses it

• A device driver is a program that controls a peripheral device such as a graphics tablet by communicating with the operating system.
• The driver translates instructions from the operating system into signals that the graphics tablet understands, and passes the artist's pen movements back to the operating system.
• The operating system loads the driver into memory when the tablet is connected, so that it can then send data to the tablet and receive input from it.
• Without a driver the operating system cannot control the tablet, so the tablet does not work.

Why each peripheral needs its own driver

• Every make and model of peripheral uses its own set of commands, so a driver is written for that particular device.
• The drivers already installed for the studio's older tablets do not work with the new model, even though both are graphics tablets.
• An operating system includes drivers for many common devices, but it does not have one for a brand new model.
• The correct driver means the pen movements are received by the computer in the form the drawing program expects.

What must be done before an artist can use a new tablet

• The new tablet is supplied with its driver on a disc or as a download, and it must be installed on each computer.
• The operating system may need to be updated so that it recognises the new model.
• The driver must be enabled or selected for the tablet once it is installed.
• Drivers are updated later to fix faults or to improve performance.
• If the correct driver is not installed, the tablet does not work or some of its features are not available.

Additional guidance

• Level 3 responses must explain why a driver is specific to a device and what must be done before an artist can use a new tablet, as well as describing what a driver is, all applied to the studio.
• Responses that only state what a driver is, or that state a driver must be installed without explaining why the tablet needs its own driver, are limited to Level 1.
• Accept 'software', 'program' or 'set of instructions' for a driver.
• Do not accept a device driver described only as a cable or a physical connection.
• Do not accept the claim that all drivers are already built into the operating system, or that one driver works for every graphics tablet.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Indicative content

How the CPU is shared between processes

• The operating system uses multitasking to give each process a short time slice on the CPU, so the music, video editor and download appear to run at the same time.
• The operating system decides which ready process will run next, so one program cannot keep the CPU to itself.
• The operating system can stop a running process and move it back to ready when its time slice ends, so all processes make progress.

The states a process can be in

• When a program is opened, the operating system creates a process and moves its instructions into RAM so it is ready.
• The operating system moves a ready process to running when the CPU is free.
• A running process becomes blocked when it is waiting for input or data, such as the download waiting for data to arrive.
• When the process finishes, the operating system terminates it and releases the resources it was using.

How the operating system responds when a process needs attention

• An interrupt is a signal to the CPU that needs immediate attention, so the operating system suspends the current process and runs the interrupt handler.
• A hardware interrupt could be a printer out of paper, and a software interrupt could be an error in a program.
• After the interrupt has been handled, the operating system can return the interrupted process to the CPU.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Additional guidance

• Level 3 responses must cover at least two of scheduling, process states and interrupts.
• A response that only states that the OS 'manages processes' or gives a program a turn, without expansion, is limited to Level 1.

Indicative content

How malware could affect the charity's computers

• A virus could damage or delete the charity's files, such as its records of donations.
• Spyware could record keystrokes and send staff passwords or personal data to a hacker.
• A Trojan horse could hide malicious code inside a useful-looking program that a volunteer downloads, so it is installed without the user knowing.
• Malware could spread from one laptop to another through files shared on the charity's network, so more laptops become infected and more files are lost.

How anti-malware software finds and deals with malware

• It scans files and compares their code with a database of known malware patterns (signatures) to identify a match.
• It can apply rules (heuristics) to decide whether a program is behaving suspiciously.
• A suspicious file can be run in a sandbox to see whether its behaviour is malicious.
• When malware is found, the file is quarantined so that it cannot run, and it can be deleted.
• Downloads and email attachments can be scanned before a member of staff opens them.

What else the charity must do for the anti-malware software to be effective

• The database of malware definitions must be kept up to date, or new malware will not be recognised.
• Staff and volunteers should be trained not to open unexpected attachments or download from unreliable sites.
• Backups are still needed, because anti-malware cannot repair files that malware has already damaged.
• Scheduled scans must be allowed to run on all 15 laptops, so that malware is found even if no one opens the file.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Level 3 responses must cover both how malware could affect the computers and how anti-malware software finds or deals with it; a brief deal-with point and an unexplained update point, with no identification method and no effect on the charity's files, are Level 1.

Do not accept anti-malware software described as a firewall, or 'scans files'/'finds viruses' on its own as a method of identifying malware.