Edexcel GCSE Computer Science (1CP2) Exam Questions

Award one mark for any of the following:

• To repair/recover corrupted/damaged files so they can be opened/used again (1)
• To recover as much of the data as possible from a damaged file (1)
• To reconstruct parts of a damaged file (1)

Allow "to fix corrupted files".

Do not accept "to repair the hard disk" (disk repair).

Do not accept "to recover deleted files" (file repair recovers corrupted/damaged files, not deleted ones).

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

• Manages user accounts/profiles/logins (1)
• Authenticates users when they log in (through passwords/biometrics) (1)
• Controls what each user is allowed to access (access rights/permissions) (1)
• Sets which files/folders/resources a user can use (1)
• Gives different levels of access to different users (e.g. administrator/standard user) (1)

Allow 'decides which users can use the computer' for the manage user accounts/logins mark.

Allow references to access to files/folders/resources for the access rights mark, as this is part of user management, not file management.

Do not accept 'manages users' on its own.

Do not accept 'controls user access' on its own, as it is unclear whether this means logging in or access rights.

Do not accept 'manages files' or 'manages peripherals' (these are other operating system functions).

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 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:

• The memory can be reused/allocated to another program (1) so other programs have enough main memory to run (1)
• Freeing the memory stops main memory becoming full (1) so the computer can load/run new programs (1)
• The closed program's data is no longer needed (1) so keeping it would waste main memory (1)
• The operating system can give the freed memory to a program that needs more (1) so that program can continue to run (1)

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

Do not accept 'to make the computer faster' on its own without saying how freeing memory helps.

Do not accept 'to delete the program' or 'to save the program' because closing a program does not remove it from secondary storage.

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

• The operating system keeps a record of where each file is stored (1) so files can be found/retrieved later (1)
• The operating system keeps files in separate storage locations (1) so files are not overwritten/lost (1)
• The operating system allocates files to folders/directories (1) so it can keep track of the files stored on the disk (1)
• The operating system deletes/moves files (1) so storage space is freed/reused (1)

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

Do not accept 'it manages files'/'it organises files' without expansion as to what is managed or organised.

Do not accept 'so files are managed/organised' as the linked reason.

Do not accept 'so the computer works' as the linked reason.

Indicative content

User accounts

• Each student and teacher should have their own user account, so the operating system can identify the person who is logged on.
• The operating system keeps a record of all valid users on the computer, so unknown users are not allowed to log in.
• A separate home area or folder can be created for each account, so a student's saved work is kept apart from other users' work.
• An account can be disabled when a student leaves the school, so they can no longer access the computers.

Authentication

• A username and password can be required at login, so only users with the correct details can use the computer.
• The operating system checks the entered password against the stored password for that account before allowing access.
• Users should be encouraged to choose a strong password, which makes it harder for someone else to guess and log in.
• The operating system can lock an account after several failed login attempts, which reduces the chance of someone trying passwords repeatedly.

Benefits for the school

• Many students can share the same computers because each person's files are kept separate.
• Work is less likely to be deleted or changed by another student, because users only see their own files.
• The school can see which account was used on a computer, so misuse can be traced to a user.
• Teachers can be confident that only authorised people can use the library computers.
• The school does not need a separate computer for every student, so it saves money.

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 user accounts and authentication, and apply them to the school library.

Do not accept general operating system functions such as file management or process management unless they are explicitly linked to managing users.