Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• So that it does not overwrite/use memory that is already being used by another program (1)
• So that it can find the program/data again when the program needs it (1)
• So that it knows which memory locations are free/can be allocated to a new program (1)
• So that it can keep the data used by each program separate from other programs (1)
• So that it can free the memory when the program is closed/knows which memory to release (1)

Do not accept 'so the program runs faster'.

Do not accept 'so that the program is not lost when the power is turned off' (this is about saving files to secondary storage, not main memory).

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).

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

• Data is sent to/received from the correct peripheral (1) because the operating system controls the transfer of data between the computer and each device (1)
• A new peripheral can be used as soon as it is connected (1) because the operating system installs/loads the correct device driver for that device (1)
• Data can be sent to a slow peripheral such as a printer (1) because the operating system stores it in a buffer/print queue until the device is ready to receive it (1)
• The user is told when a peripheral has a problem (1) because the operating system receives status information from the device and reports the error to the user (1)

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

Allow specific peripherals as the example (e.g. a mouse, a printer) provided the reason says what the operating system does.

Allow 'the operating system responds to an interrupt from a device' as a point, with the reason that the device is signalling that it needs attention/has finished its job.

Do not accept 'the operating system manages/controls the peripherals' or 'it lets the devices be used'/'the peripherals work correctly' on their own, as these repeat the question without saying what the operating system does.