Computer Science AS OCR
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1-1-structure-and-function-of-the-processor as5 主题
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1-2-types-of-processor as3 主题
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1-3-input-output-and-storage as2 主题
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2-1-systems-software as8 主题
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2-3-software-development as5 主题
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2-4-types-of-programming-language as4 主题
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3-1-compression-encryption-and-hashing as3 主题
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3-2-databases as3 主题
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3-3-networks as8 主题
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3-4-web-technologies as13 主题
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html as
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css as
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css-styling as
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javascript as
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variables-and-constants-in-javascript as
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outputs-in-javascript as
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selection-in-javascript- as
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for-loops-in-javascript- as
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while-loops-in-javascript- as
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strings-in-javascript- as
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operators-in-javascript- as
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nested-statements-in-javascript as
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functions-and-procedures-in-javascript as
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html as
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4-1-data-types as8 主题
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4-2-data-structures as4 主题
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4-3-boolean-algebra as1 主题
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5-1-computing-related-legislation as4 主题
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5-2-moral-and-ethical-issues as9 主题
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6-1-thinking-abstractly as3 主题
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6-2-thinking-ahead as1 主题
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6-3-thinking-procedurally as3 主题
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6-4-thinking-logically as2 主题
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6-5-thinking-concurrently as2 主题
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7-1-programming-techniques as9 主题
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8-1-standard-algorithms-and-big-o-notation as8 主题
bios as
Exam code:H046
BIOS
What does BIOS mean?
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In A Level Computer Science, BIOS refers to the Basic Input/Output System of a computer
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BIOS is a piece of firmware stored on a small memory chip on the motherboard
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On system start, the BIOS is the first software to run
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It performs a POST (Power-On Self-Test), a diagnostic testing sequence that ensures all the hardware components are working properly
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If the BIOS encounters any errors during this test, it will either halt the boot process or issue an error message
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If the POST succeeds, the BIOS will run the Bootstrap loading sequence, which is the program responsible for starting the operating system
Worked Example
In the late 1990s, the CIH virus hit the headlines because it could overwrite and destroy the contents of a computer’s BIOS.
Describe the effect of a computer having its BIOS overwritten.
[2]
How to answer this question:
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Explain the role of BIOS in a computer system
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Explain the consequence of having a destroyed BIOS
Answer:
Example answer that gets full marks:
The BIOS is crucial in initialising the hardware components and operating the system. If a virus, such as the CIH virus, overwrites or destroys the contents of a computer’s BIOS, it will be unable to perform the Power-On Self-Test (POST) and fail to load the bootstrap program. This would mean the computer will not be able to initialise the operating system.
Acceptable answers you could have given instead:
If the BIOS has been overwritten, it will not be able to perform the Power-On Self-Test (POST) and, therefore, unable to load the bootstrap program. This would mean the operating system would fail to start.
Responses