Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Embedded system (1)
• The only correct answer is A. The correct answer is embedded system.
• B is not correct because a general purpose computer can run many different application programs
• C is not correct because a networked computer is connected to other computers to share resources
• D is not correct because a server computer provides services or resources to other computers on a network

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

• An arithmetic operation, e.g. addition/subtraction/multiplication/division (1)
• A logical operation, e.g. comparing two values (is A > B?) / using AND, OR, NOT (1)

Do not accept decoding instructions, fetching instructions or controlling the timing of the CPU, as these are carried out by the control unit.

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

• Makes a copy/duplicate of the files/data (1) and stores it on a separate storage device/at a different location (1)
• Copies the data at regular intervals (1) so a recent version is available if the original is lost (1)
• Keeps a copy of the files (1) so that the data can be restored after the original is deleted/corrupted (1)
• Stores the copies on another device (1) so the data is not lost if the original device fails/is damaged by a fire or flood (1)

Do not accept 'it backs up the files' on its own, as this repeats the question.

Do not accept responses about repairing corrupted files or removing malware, as these are different utility programs.

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

• The processor/CPU can only execute machine code/binary instructions (1) so the assembly instructions must be converted into machine code before the program can run (1)
• Each assembly instruction/mnemonic matches/corresponds to one machine code instruction (1) so each line must be replaced with the machine code the processor executes (1)
• The program is written using mnemonics (1) that must be translated into machine code for the processor to carry out the instructions (1)
• The hardware/processor does not understand assembly language directly (1) so it must be translated into machine code that the processor can execute (1)

Do not accept 'assembly language is a low-level language'.

Do not accept 'it is hard to understand' or 'it is not English'.

Do not accept benefits, such as 'machine code runs faster' or 'the program will run more quickly'.

Do not accept 'an assembler/a translator converts it' on its own, with no reference to the processor only being able to execute machine code/binary.

Do not accept responses about high-level languages or about compilers/interpreters.

Indicative content

How the CPU is shared between processes

• The operating system uses multitasking to give each process a short time slice on the CPU, so the music, video editor and download appear to run at the same time.
• The operating system decides which ready process will run next, so one program cannot keep the CPU to itself.
• The operating system can stop a running process and move it back to ready when its time slice ends, so all processes make progress.

The states a process can be in

• When a program is opened, the operating system creates a process and moves its instructions into RAM so it is ready.
• The operating system moves a ready process to running when the CPU is free.
• A running process becomes blocked when it is waiting for input or data, such as the download waiting for data to arrive.
• When the process finishes, the operating system terminates it and releases the resources it was using.

How the operating system responds when a process needs attention

• An interrupt is a signal to the CPU that needs immediate attention, so the operating system suspends the current process and runs the interrupt handler.
• A hardware interrupt could be a printer out of paper, and a software interrupt could be an error in a program.
• After the interrupt has been handled, the operating system can return the interrupted process to the CPU.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Additional guidance

• Level 3 responses must cover at least two of scheduling, process states and interrupts.
• A response that only states that the OS 'manages processes' or gives a program a turn, without expansion, is limited to Level 1.