AQA · GCSE · Computer Science
Course version: 8525 · Version from Sept 2020
Understand that assembly language has a 1:1 correspondence with machine…
Full specification wording
Classification of programming languages and translators: understand that assembly language has a 1:1 correspondence with machine code.
Machine code is the binary instructions a processor executes directly.
Checked against the AQA 8525 specification (opens in a new tab) on .
- Point 8 of 19
Study notes
From the checked teaching notes for this specification point.
The idea
Machine code is the binary instructions a processor executes directly. Assembly language uses short mnemonic instructions, such as a load or add operation, that each correspond to one machine code instruction. This one-to-one correspondence means one assembly instruction is translated into exactly one machine code instruction, usually by a program called an assembler. It does not mean the binary patterns are identical to the text; it means the mapping is one instruction to one instruction, with no expansion into several machine instructions. This contrasts with high-level languages, where a single statement may translate into many machine code instructions. Understanding the 1:1 relationship helps explain why assembly programs are compact and give precise control, and why an assembler is a relatively direct translator compared with a compiler.
What earns the marks
- Machine code consists of binary instructions executed directly by the processor.
- Assembly language uses mnemonics that each map to one machine code instruction.
- The 1:1 correspondence means one assembly instruction translates to exactly one machine code instruction.
- An assembler translates assembly language into machine code.
Common mistakes and how to put them right
Saying assembly and machine code are the same thing.
Put it right by explaining assembly uses mnemonics while machine code is binary, linked one-to-one.
Thinking 1:1 means one assembly instruction becomes many machine instructions.
Put it right by stating it becomes exactly one.
Naming a compiler as the translator of assembly.
Put it right by naming the assembler.
Exam tips
- Use the phrase 'one assembly instruction to one machine code instruction' to make the 1:1 idea explicit.
- Contrast with a high-level language statement expanding into several machine instructions to show understanding.
- Name the assembler as the translator when the question asks how assembly becomes machine code.
Try the lesson
The start of the Classification of programming languages and translators: understand that assembly language has a 1:1 correspondence with machine code. lesson, made from checked teaching notes for this specification point.
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What does it mean that assembly language has a 1:1 correspondence with machine code?
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