AS-Level OCR 2025 Computer Science Paper 1

Oxford Cambridge and RSA



AS-Level OCR 2025 Computer Science Paper 1




Tuesday 13 May 2025 – Afternoon


AS Level Computer Science


H046/01 Computing principles


Time allowed: 1 hour 15 minutes




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1 The table shows the steps of the Fetch stage only of the Fetch-Decode-Execute cycle. The
names of the registers are referred to as A, B, C and D.

1 The contents of the Register A are copied into the Register B.

2a RAM is read at the location specified by the Register B and its contents are copied into
the Register C.
2b Register A is incremented by 1.

3 The contents of the Register C are copied into the Register D.


(a) State the name of each register in the table.


Register A


Register B


Register C


Register D

[4]

(b) Describe how the performance of the Fetch-Decode-Execute cycle changes when increasing:

(i) The number of cores

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(ii) The clock speed

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