Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• The start and end address/size of the block allocated to each program is recorded (1) so the operating system knows which areas of main memory are in use and which are free (1)
• The record is checked before memory is allocated (1) so memory already in use is not given to another program/is not overwritten (1)
• The record is searched for a free block that is large enough (1) so a newly loaded program is placed in a suitable area of main memory (1)
• The record is updated when a program ends/closes (1) so the memory it was using is marked as free for other programs (1)

Allow the record to be called a memory map/memory table/allocation table.

A response that only says the operating system keeps a record/list of the memory each program is using, without saying what the record contains, earns 0 marks.

A response that states what the record contains, e.g. the addresses/the start and end address of each block, earns 1 mark even if it does not say how the record is used.

Do not accept responses about saving programs/files to secondary storage or about moving programs to virtual memory, as these are not uses of this record.

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 keeps a record of where each file is stored (1) so files can be found/retrieved later (1)
• The operating system keeps files in separate storage locations (1) so files are not overwritten/lost (1)
• The operating system allocates files to folders/directories (1) so it can keep track of the files stored on the disk (1)
• The operating system deletes/moves files (1) so storage space is freed/reused (1)

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

Do not accept 'it manages files'/'it organises files' without expansion as to what is managed or organised.

Do not accept 'so files are managed/organised' as the linked reason.

Do not accept 'so the computer works' as the linked reason.