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:

• 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 CPU can only execute one process at a time (1) so the operating system must decide which process runs next (1)
• Each process needs CPU time (1) so the operating system must share the CPU between processes (1)
• One process could use the CPU for too long (1) so the operating system must give other processes a turn (1)
• A process may be waiting for a resource or user input (1) so the operating system can run another process that is ready (1)
• The user wants to run more than one program (1) so the operating system must manage which process uses the CPU and when (1)

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

Allow 'program' for 'process'.

Do not accept 'to manage processes' / 'so processes are managed' without a reason.

Do not accept answers about managing files, memory or peripherals.

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.