Edexcel GCSE Computer Science (1CP2) Exam Questions

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:

• 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.

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

• Device drivers/drivers are used/installed (1) so the operating system can control/communicate with a peripheral (1)
• Data is transferred between the computer and a peripheral (1) so input can be read/output can be produced (1)
• Interrupts from devices/peripherals are handled (1) so the processor can respond when a device needs attention/has finished (1)
• Each peripheral is allocated to a process (1) so two processes do not try to use the same device at the same time (1)
• Print jobs are held in a queue/spooled (1) so several jobs can be sent to one printer and printed one at a time (1)
• Errors from a peripheral are handled/reported (1) so the program using the device does not crash (1)

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

Allow other valid functions of peripheral management that are explained, e.g. sending data to a peripheral in the correct format, reporting a device error to the user.

Do not accept 'it manages peripherals' / 'it controls the hardware' on its own as it repeats the question.

Do not accept 'it installs the printer' / 'it connects the peripheral' on its own without saying what the operating system does with the device or why.

Do not accept cleaning/maintaining a peripheral; that is not peripheral management by the operating system.