Edexcel GCSE Computer Science (1CP2) Exam Questions

• C To make sure existing programs and data are not overwritten (1)
• The only correct answer is C. The correct answer is to make sure existing programs and data are not overwritten.
• A is not correct because deciding which process runs next and for how long is not why the locations of programs in memory are recorded
• B is not correct because a program is only moved to secondary storage when virtual memory is used
• D is not correct because multi-tasking lets more than one process use the CPU in turn

• C Peripheral management (1)
• The only correct answer is C. The correct answer is peripheral management.
• A is not correct because a device driver is a program that controls one type of peripheral device
• B is not correct because file management names, saves, moves and deletes files
• D is not correct because process management allocates time on the CPU to programs

Award one mark for any of the following:

• It frees/releases the memory (1)
• The memory is marked as available/empty so that another program can use it (1)
• The program and its data are removed/deleted from main memory (1)

Allow 'the memory is cleared'.

Do not accept 'it deletes the program from the hard disk' (the program is stored in secondary storage and is not removed).

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

• Creating/deleting user accounts (1)
• Storing usernames and passwords (1)
• Checking login details/authenticating a user at login (1)
• Setting access rights/permissions for each user, e.g. restricting which files/folders/programs/drives they can access (1)

Allow logging in as an example of checking login details.

Do not accept managing users on its own.

Do not accept provides a user interface, as this is not user management.

Do not accept managing files or managing processes, as these are other functions.

Do not accept stopping hackers/protecting from malware, as this is security, not user management.

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:

• Decides which process is given use of the CPU (1) so that more than one program can run/appear to run at the same time (1)
• Allocates CPU time to each process (1) so that no single process takes control of the CPU (1)
• Manages the states/life-cycle of each process (1) so processes can be moved between ready/running/blocked (1)
• Keeps track of the processes and their status (1) so a process waiting for a resource can be returned to the CPU when it is ready (1)

Do not accept responses that only describe what a process is.

Do not accept responses that only list the types of operating system management.

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

• Allocates memory/RAM to the process (1) so its instructions and data can be stored (1)
• Loads/moves the program instructions into RAM (1) so the process is ready to run (1)
• Adds the process to the ready queue (1) so it can be scheduled onto the CPU (1)
• Gives the process a process ID (PID)/identifier (1) so the operating system can track/manage it (1)

For both marks, the development must follow/be linked to the point.

Only award one of the first two bullets in any one response; allocating memory and loading into RAM are the same stage.

Accept 'memory' for 'RAM' and vice versa.

Accept 'added to a queue for the processor' for the ready queue point.

Do not accept responses that say the process is run on the CPU straight away.

Do not accept descriptions of the program executing/running its instructions, or of the program file being created/saved.

Do not accept responses about the process being blocked or terminated.

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:

• The operating system decides which process will use the CPU next (1) so the processor is shared between processes/processes take turns (1)
• The operating system allocates CPU time to each process/gives each process a small amount of time on the CPU (1) so multitasking can take place/several programs can appear to run at once (1)
• The operating system manages the state of each process, e.g. ready/running/blocked (1) so a process waiting for input/blocked does not stop other processes running (1)
• The operating system can terminate/end a process that has stopped responding (1) so it does not affect other processes/the computer keeps working (1)

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

Do not accept the idea that the CPU runs two or more processes at exactly the same time; multitasking shares CPU time.

Do not accept 'the OS shares the CPU' on its own without saying how/why, e.g. giving each process a turn/CPU time.

Do not accept 'it stops programs crashing' without a link to process management, e.g. ending a process that has stopped responding.

Do not accept 'it manages processes' without saying what the operating system does.