Edexcel GCSE Computer Science (1CP2) Exam Questions

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

• The (same) program/source code can run on different types/makes of computer/processor (1)
• With few/no changes (to the program code) (1)
• The same source code can be translated for each type of processor (1)
• A different compiler/interpreter is used for each type of processor (1)
• The program does not depend on one specific type of processor/hardware (1)
• Only one version of the program needs to be written/kept (1)
• The program is portable between different computers (1)

Allow 'different computers' as meaning different types of computer/processor.

Do not accept a program that will only run on one type of computer / the computer it was written on.

Do not accept written in machine code/binary, is translated into machine code, compiled/interpreted, is a low-level language.

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

• It can control/manipulate the hardware (components/registers/memory locations) directly (1)
• Each instruction maps to a single machine-code instruction, so the behaviour/timing can be controlled precisely (1)
• The code can run very quickly / has a fast execution time (1)
• The code uses less memory/RAM (1)
• The code can be optimised for a particular processor/chipset (1)

Only award one mark where both 'controls the hardware' and 'accesses registers/memory locations' are given, as these are the same point.

Do not accept 'it is closer to the hardware' without saying that it controls or accesses the hardware directly.

Do not accept easier/faster to write/program/learn/understand/debug (these are advantages of high-level languages).

Do not accept faster/quicker without qualification.

Do not accept portable/machine independent.

Do not accept does not need to be translated/compiled (assembly language must be assembled).

Do not accept it is a low-level language / a repeat of the question.

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

• Statements are written using words/phrases that look like English or maths (1) so the code is easier to read/understand/write (1)
• One statement is translated into several machine code instructions (1) so programs are shorter to write than in a low-level language (1)
• High-level languages provide built-in data structures such as arrays/lists/records (1) so a collection of data items can be stored and accessed under one name (1)

Do not accept responses that only give a benefit or drawback, such as 'it is easier to learn', with no characteristic.

Do not accept 'it is easier than a low-level language' without saying what the characteristic is.

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

• The compiler translates the whole program into machine code before it is run (1) so no translation is needed while the program is executing (1)
• The machine code/object code is already produced before execution (1) so the CPU can carry out the instructions directly without translating them (1)
• The compiled program does not need an interpreter at run time (1) so no time is spent translating each line before it is executed (1)

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

A statement that translation happens before execution, with no linked reason for faster running, earns 1 mark only.

Do not accept 'faster to run' or 'quicker' on its own without a reason linked to translation before/during execution.

Do not accept 'compiled code is optimised' or 'compilation takes less time' without linking this to translation before execution/at run time.

Do not accept answers about the compiler being installed or available.

The question asks why a compiled program usually runs faster, so answers must refer to when translation happens, not just general performance claims.