Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• The memory (that was) used by the program is freed/released/marked as free (1) so it can be allocated/reused by another program/process (1)
• The operating system's memory allocation table/record (of memory in use) is updated (1) to show that the program's memory locations/blocks are now free/available (1)
• The program's instructions/data are removed/overwritten in main memory (1) so the space they used is no longer reserved for that program (1)
• The memory pages/blocks allocated to the program are returned to the list of free pages/blocks (1) that can be used when the next program is loaded (1)

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

Do not award two marks for the same idea described twice (e.g. the memory is freed and added to a list of free blocks); the two marks must come from two different linked descriptions.

Do not accept responses about closing the program window, stopping/terminating the program/process, saving the file or deleting the program from secondary storage/the hard disk.

Ignore statements that main memory is 'managed'/'cleaned up' with no development.

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

• The operating system receives signals/data from the graphics tablet (1) and converts them into data the program can use/process (1)
• The operating system receives data from the graphics tablet (1) and passes/forwards it to the program being used/the active program (1)
• The tablet's device driver receives/interprets the signals/data from the tablet (1) so the operating system can pass the input to the program (1)
• The operating system identifies the graphics tablet as the source of the input (1) so the data is sent to the correct program (1)

Accept 'signals' for 'data' throughout.

Accept reference to the device driver only where it is linked to receiving/interpreting the input (e.g. the driver receives the tablet's signals (1) so the OS can pass data to the program (1)).

Do not accept 'the operating system uses a driver' on its own, without saying what the driver does with the input.

Do not accept generic statements such as 'the operating system runs the tablet' as a description of how input is managed.

Do not accept responses that say the operating system creates/finishes the drawing, or that the tablet stores the input permanently.

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.