Edexcel GCSE Computer Science (1CP2) Exam Questions

Award one mark for any of the following:

• To make/keep a copy of files/data (1)
• To store the copy separately from the original, e.g. on a different device/in a different location (1)
• So that data can be restored if the original is lost/damaged/corrupted (1)

Do not accept "to save files" on its own, as saving is normal file management and does not make a separate copy.

Do not accept answers that describe a different utility, such as scanning for malware/viruses (anti-malware software).

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 explanation such as:

• The operating system switches rapidly between processes (1) so each process runs for a short time slice before the next one starts (1)
• Each process is given a small amount of CPU time (1) so the CPU moves on to another process when that time is up (1)
• The operating system chooses which process to run next (1) so the CPU is shared between the programs (1)
• Processes take turns to use the CPU (1) because the CPU is so fast the user does not notice the switching (1)
• Only one process can run on the CPU at a time (1) so the operating system must swap processes in and out quickly (1)

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

Allow 'time slice' / 'time quantum'.

Do not accept 'the computer has more than one CPU' / 'each program runs on its own CPU'.

Do not accept 'the CPU does two things at once' without saying processes take turns/are switched.

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

• The operating system uses the printer's device driver to communicate with the printer (1) so the print job is sent as commands the printer can carry out (1)
• The operating system holds print jobs in a queue/buffer (1) because the computer sends data faster than the printer can print it (1)
• The operating system reports the printer's status to the user (1) so the user knows what to do when there is a problem such as the paper running out (1)
• The operating system handles interrupts/signals from the printer (1) so a problem such as a paper jam is dealt with while other programs carry on running (1)

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

Allow a point about the operating system loading/installing the device driver for a new printer (1) provided the second mark gives a reason that is not the same as the driver communication point, e.g. so the new printer can be used/controlled by the operating system (1)

Award 1 mark for stating that print jobs are held in a queue/a buffer; the second mark needs the linked reason that the printer prints more slowly than data is sent.

Do not accept restating the question, e.g. 'it manages the printer' or 'it controls the peripherals', without saying how or why.

Do not accept 'it lets the printer connect to the computer' or 'it stops the printer being damaged' without a linked reason.

Do not accept 'it makes the printer print faster' as the operating system cannot increase the printer's speed.