Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• File repair (software) (1)
• Backup (software) (1)
• Data compression (software) (1)
• Disk defragmentation (software) (1)
• Anti-malware (software) (1)

Allow antivirus software.

Do not accept file management, process management, peripheral management or user management, as these are functions of the operating system.

Do not accept operating systems (e.g. Windows, Linux) or application software (e.g. word processor, web browser).

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

• The program (and its data) is copied/loaded from secondary storage into main memory/RAM (1) so that the CPU can fetch/execute its instructions (1)
• An area of main memory is allocated/reserved for the program (1) that is large enough to hold the program and its data (1)
• The operating system checks that there is enough free main memory (1) before the program can be started/loaded, otherwise it cannot run/an error is reported (1)
• The operating system keeps a record of the memory addresses used by the program (1) so that its instructions and data can be found when it runs (1)

Allow 'loaded into RAM', 'stored in memory' and 'put into main memory' as equivalent to copied into main memory.

A single statement that the program is loaded/stored in main memory, with no linked development, can be given one mark only.

Do not accept descriptions of the CPU fetching/executing instructions that do not refer to the operating system loading or allocating memory.

Do not accept responses about virtual memory (moving processes to secondary storage) or about which process runs next on the CPU.

Do not accept the program being run from secondary storage/hard disk.

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

• It keeps a record of which memory addresses/areas belong to each program and to the operating system (1) so it knows which addresses a program is allowed to use (1)
• Each program is given its own area of main memory (1) so a program cannot write to the addresses used by another program or by the operating system (1)
• The memory used by the operating system is marked as protected/reserved (1) so a program that tries to write to it is blocked/causes an error (1)
• The address a program writes to is checked against the record of its allocated area (1) and the write is stopped if the address is outside that area (1)

Allow the memory being protected to be that of the operating system or of another program.

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

Do not award generic answers such as 'the operating system manages memory' or 'the operating system keeps track of memory'.

Do not award responses about stopping programs using too much memory or allocating memory, as these are not about protecting memory being overwritten.

Do not award responses about virtual memory, paging or moving processes to secondary storage.

Do not award responses about firewalls, antivirus software or passwords.

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).