Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• Creating/deleting user accounts (1)
• Storing usernames and passwords (1)
• Checking login details/authenticating a user at login (1)
• Setting access rights/permissions for each user, e.g. restricting which files/folders/programs/drives they can access (1)

Allow logging in as an example of checking login details.

Do not accept managing users on its own.

Do not accept provides a user interface, as this is not user management.

Do not accept managing files or managing processes, as these are other functions.

Do not accept stopping hackers/protecting from malware, as this is security, not user management.

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

• Updates/changes the location/path stored for the file (1) so the file can be found in its new folder/location (1)
• Removes the file's entry/reference from the old folder (1) so the file no longer appears/is listed there (1)
• Adds/creates an entry/reference for the file in the new folder (1) so the file appears/is listed in its new location (1)
• Updates the folder/directory listing/structure (1) to show the file's new location/path (1)

Do not accept descriptions of copying the file or leaving a duplicate in the old folder.

Do not accept deleting and recreating the file, or moving the file's data to a different physical location on the disk; the marks are for updating the folder/directory structure.

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 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.