Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• The file's entry is removed from the folder/directory (1) so the file no longer appears in the list of files/is no longer listed (1)
• The (disk) space used by the file is marked as free/available/unused (1) so another file can be saved/stored in that space (1)
• The file's data/contents are not erased/removed (1) so the file may still be recovered until the space is overwritten (1)

A point stated without development, e.g. 'the file is removed from the folder', earns one mark only.

For the first mark, accept that the file's entry is removed from the folder/directory; the second mark must state that the file no longer appears/is listed.

Do not accept 'stays on disk' alone for the third point; accept 'data is not erased' or 'contents remain'.

Do not accept 'the file is wiped from the disk straight away' or 'the data is destroyed and can never be recovered'.

Do not accept 'the file is moved to the recycle bin/bin' or 'the file is deleted from the hard drive' on its own, as this does not describe what happens to the file or the disk space.

Do not accept responses about moving the file to another folder.

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

• The start and end address/size of the block allocated to each program is recorded (1) so the operating system knows which areas of main memory are in use and which are free (1)
• The record is checked before memory is allocated (1) so memory already in use is not given to another program/is not overwritten (1)
• The record is searched for a free block that is large enough (1) so a newly loaded program is placed in a suitable area of main memory (1)
• The record is updated when a program ends/closes (1) so the memory it was using is marked as free for other programs (1)

Allow the record to be called a memory map/memory table/allocation table.

A response that only says the operating system keeps a record/list of the memory each program is using, without saying what the record contains, earns 0 marks.

A response that states what the record contains, e.g. the addresses/the start and end address of each block, earns 1 mark even if it does not say how the record is used.

Do not accept responses about saving programs/files to secondary storage or about moving programs to virtual memory, as these are not uses of this record.

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.

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

• The operating system decides which process will use the CPU next (1) so the processor is shared between processes/processes take turns (1)
• The operating system allocates CPU time to each process/gives each process a small amount of time on the CPU (1) so multitasking can take place/several programs can appear to run at once (1)
• The operating system manages the state of each process, e.g. ready/running/blocked (1) so a process waiting for input/blocked does not stop other processes running (1)
• The operating system can terminate/end a process that has stopped responding (1) so it does not affect other processes/the computer keeps working (1)

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

Do not accept the idea that the CPU runs two or more processes at exactly the same time; multitasking shares CPU time.

Do not accept 'the OS shares the CPU' on its own without saying how/why, e.g. giving each process a turn/CPU time.

Do not accept 'it stops programs crashing' without a link to process management, e.g. ending a process that has stopped responding.

Do not accept 'it manages processes' without saying what the operating system does.

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)