Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• Receives input from/sends output to peripheral devices (1)
• Communicates with/controls a peripheral using its device driver, including installing the driver for a new device (1)
• Manages the print queue/buffer so that print jobs are sent to the printer in turn (1)
• Reports the status of a device/a device error to the user, e.g. out of paper (1)

Allow answers that name a specific peripheral, as long as they also say what the operating system does with it, e.g. 'it controls the printer using its driver'.

Do not accept 'manages peripherals'/'controls the hardware' on its own, as this repeats the question.

Do not accept 'managing files' or 'managing users' (file management and user management are other functions of an operating system).

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

• Allocates memory/RAM to the process (1) so its instructions and data can be stored (1)
• Loads/moves the program instructions into RAM (1) so the process is ready to run (1)
• Adds the process to the ready queue (1) so it can be scheduled onto the CPU (1)
• Gives the process a process ID (PID)/identifier (1) so the operating system can track/manage it (1)

For both marks, the development must follow/be linked to the point.

Only award one of the first two bullets in any one response; allocating memory and loading into RAM are the same stage.

Accept 'memory' for 'RAM' and vice versa.

Accept 'added to a queue for the processor' for the ready queue point.

Do not accept responses that say the process is run on the CPU straight away.

Do not accept descriptions of the program executing/running its instructions, or of the program file being created/saved.

Do not accept responses about the process being blocked or terminated.

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

• Each user/file is given permissions/access rights (1) so other users cannot read/write/open/change that user's files (1)
• A user may be given read-only/read access to a file (1) so they cannot edit/delete/change it (1)
• Each file is given permissions/access rights for different users (1) so the operating system allows/refuses access depending on which user is logged in (1)
• The operating system checks a user's permissions/access rights when a file is opened (1) so a user with read-only/read access cannot save/delete changes (1)

Do not accept responses about asking for a password/username, as this checks who the user is, not what they are allowed to do.

Do not accept 'files are protected/safe' or 'access rights protect files' without saying how access is limited (e.g. read-only access, permissions for different users).

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

• It allows the operating system/OS to communicate with the device/printer (1) because it translates the commands into signals the device understands (1)
• It contains/sends the instructions/commands needed by a particular device (1) so the device carries out the correct actions (1)
• It controls the device/printer (1) by sending commands/signals to it (1)
• Different devices need different commands (1) so each one needs its own driver to work with the operating system (1)

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

Do not accept 'it drives/controls the device' on its own without saying how, e.g. by sending commands/signals.

Do not accept hardware/a physical device (a device driver is software).

Do not accept 'it connects the printer to the computer' or 'it installs the printer' without saying that it provides the instructions/commands for the device.

Indicative content

How files become fragmented

• A file is saved into free blocks on the disk, so as files are deleted and new ones saved, one file can end up split across blocks in different places.
• Large files are more likely to become fragmented because they may not fit into one free space.
• The more the disks are used, the more fragmented they become, so the read/write head has to move to more locations to read all the parts of a file.
• Fragmentation is the reason that files on the college's computers take a long time to open.

What defragmentation software does

• It reorganises the blocks of each file so that they are stored together (contiguously) on the disk.
• It collects the free space into one block so that new files are written in one piece and are less likely to be fragmented.
• It is a housekeeping utility that is often supplied with the operating system, and it reorganises data that is already on the disk.
• It does not change the contents of any file, it only changes where the blocks of the file are stored.

Benefits of running it

• Files and programs open faster because the read/write head makes fewer movements, so the older computers feel quicker without the college buying new hardware.
• Free space in one block means new files are written in one piece, so the improvement lasts for a while.
• Running it may mean the college can keep using the older computers for longer instead of replacing them.

Drawbacks of running it

• It can take a long time to run, so it should be scheduled for when the room is not in use, such as overnight or at weekends.
• It causes a lot of disk activity, so running it too often puts unnecessary strain on the disks.
• It does not free up any space, as no files are deleted, so the disks will still be almost full.
• It only reorganises files that are intact, so it cannot recover a corrupted file, and a backup is still needed.

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 files become fragmented and what defragmentation software does, with at least one benefit or drawback applied to the college's computers. An answer that only states what the software does and one benefit, with no explanation of how files became fragmented and no drawback, is Level 1 (2 marks).

Do not accept: defragmentation software compresses files, frees up storage space, deletes unused files, repairs corrupted files, or speeds up the processor or internet connection.