Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• Decides/allocates which part/space on the disk a file is written to (1)
• Keeps an index/record of the location of each file so that it can be found/retrieved (1)
• Prevents a file from being overwritten by another file (1)
• Checks there is enough free space on the disk before a file is saved (1)

Allow 'file allocation table' for keeping an index/record of file locations

Only award one mark for answers that say the operating system decides/allocates where a file is stored or allocates free space on the disk

Do not accept defragmentation

Do not accept 'stores files', 'saves files' or 'backs up files' (these only repeat the stem)

Do not accept 'organises files into folders' on its own

Do not accept scheduling processes or managing peripherals

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 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).

Indicative content

Administrator accounts

• An administrator account can create new user accounts for new employees and delete accounts when employees leave.
• The administrator can reset a forgotten password, so an employee can get back to work without sharing another person's account.
• The administrator can set the access rights for each user or group, so designers get access to project folders and only directors can open salary files.
• Administrator privileges should be given to only a few trusted employees, as administrators can change any settings on the system.

Standard user accounts

• Designers should use standard user accounts, so they cannot install unauthorised software or change system settings.
• A standard user can be given permission to read and write files in the project folder that their team uses.
• Standard users should not be able to change other users' permissions, so the access rules cannot be removed by accident.
• If a standard user tries to open a file without permission, the operating system denies access.

File permissions

• Each file or folder can have permissions that allow a user to read, write or delete it.
• Project folders can be set so all designers can read and write the files inside them.
• Salary files can be set so only directors can read them, and other users are denied access.
• Permissions can be set for a group of users, such as all designers, which is quicker than setting them for each person.
• A file can be made read-only for standard users, so they can view it but cannot change it.

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 administrator accounts, standard user accounts and file permissions, and apply them to the design company.

Do not accept general operating system functions such as managing the processor or memory unless they are explicitly linked to controlling what a user can access.