9618Paper 3 · Advanced Theory§15.1, §15.2

15. Hardware and Virtual Machines

RISC vs CISC, pipelining, parallel processing (SISD/SIMD/MISD/MIMD), massively parallel computers, virtual machines — plus Boolean algebra, De Morgan's laws, Karnaugh maps, adders and flip-flops.

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Statometer68CoreNext Paper 395%

Marks a paper13.7 · 18%Rank#4 of 8 · #2 on P3Trend · last 12→Full stats

Everything for this topic — study hub

A2 Level · 9618 · Paper 3

Statometer — what 32 real papers say about this topic and each of its 2 syllabus bullets

Core · #4 of 8 in A2 Level · recomputed with every new session

Core#4 of 8 in A2 Level#2 on Paper 3→ Steady

A regular, well-paid topic — you cannot afford a gap here.

Next Paper 3: 95%; 9 in 10 chance it is set
Marks a paper: 13.7 / 75; 18% of Paper 3 · fair share 17%
Appeared in: 32 / 32; Paper 3 sittings 2021–2026
Last set: May/Jun 2026; 9618/33 · Q6 · 8 marks · 11-series streak

Marks in each of the last 12 Paper 3 sittingsOct/Nov 24 → May/Jun 26

What the papers say

Set in 32 of 32 Paper 3 sittings on the current syllabus — treat it as certain.
Worth about 13.7 marks a paper (18% of Paper 3).
Last set May/Jun 2026 · 9618/33 · Q6 for 8 marks — in the most recent series.
Set in each of the last 11 series without a miss.
Steady at around 13.6 marks a paper year on year.
Lives on “Write” and “Complete” — 55% of its questions: you must produce something — code, a diagram, a table — practise doing it, not reading it.
52% of its questions involve a diagram, table or figure — practise with pen and paper.
50% of its questions are set out as code, pseudocode or a table to complete.
Its biggest question so far: 49 marks (May/Jun 2023 · 9618/32 · Q9).
Inside the topic, §15.2 Boolean algebra and logic circuits carries the most marks (65%) and §15.1 Processors, parallel processing and virtual machines the least (35%).
It is examined mostly as AO2 (Apply & analyse, 53%), the rest AO1 (47%) — you must apply it to the given data or scenario — work it out, trace it, explain it in context.
The examiner has commented on 33 of its questions — read “What the examiner said” before you practise.

Command words

Share of questions using the word (a question can use several). What each wants →

Question shapes

≤ 6 mk25
7–9 mk24
10–12 mk8
13–15 mk0
16+ mk1

Average 7.6 marks a question · 52% with a figure or table · 50% with code · biggest 49 marks

Assessment objectives — how it is examined

Every part of every current-syllabus question filed under Cambridge's AO1 / AO2 / AO3 (from its command word and what it asks you to do), so you know whether this topic pays for definitions, for applying, or for judging and building.

AO1 47%

AO2 53%

AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate

Paper 3 as a whole

Paper 3	Syllabus	Measured
AO1 Knowledge & understanding	60%	54%
AO2 Apply & analyse	40%	46%
AO3 Design, program & evaluate	0%	0%

Syllabus = Cambridge's grid; measured = the bank's current-syllabus papers.

Inside the topic — every syllabus bullet, measured

Each part of each question is filed under the bullet it examines; the numbers are per Paper 3 sitting, exactly like the topic's. Open a bullet for its own Statometer.

15.1Processors, parallel processing and virtual machines#6 of 14 on Paper 3Core · 6072% next paper4.1 marks23/32 sittings→ May/Jun 2026Core · 6072%
4.1 · 35% of topic23/32May/Jun 2026latest series · →
A regular earner inside the topic — most papers touch it.Syllabus: RISC vs CISC and interrupt handling; pipelining; SISD, SIMD, MISD, MIMD; massively parallel computers; virtual machines and their limits
Next Paper 3
72%
7 in 10
Marks a paper
4.1
6% of the paper · 35% of the topic
Asked in
23 / 32
Paper 3 sittings · 25 questions
Last asked
May/Jun 2026
9618/33 · Q4 · 5 marks
Asked in 23 of 32 Paper 3 sittings — about 7 papers in 10.
About 4.1 marks a paper (6% of Paper 3; 35% of the topic's marks across its 2 bullets).
Last asked May/Jun 2026 · 9618/33 · Q4 (5 marks) — in the most recent series.
Usually “Describe”: full sentences with a reason, not one-word answers.
Biggest chunk of marks so far: 8 in May/Jun 2024 · 9618/31 · Q11.
It is examined almost entirely as AO1 (Knowledge & understanding, 87%) — definitions and descriptions in syllabus words score.
Last 12 sittings→ Steady
Assessment objectives
AO1 87%
AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate
Describe52%
Outline24%
Identify24%
Explain20%
Practise its 25 questions Biggest: 8 marks · May/Jun 2024
15.2Boolean algebra and logic circuits#2 of 14 on Paper 3Banker · 9591% next paper8 marks30/32 sittings→ May/Jun 2026Banker · 9591%
8 · 65% of topic30/32May/Jun 2026latest series · →
Asked in nearly every paper — the bullet to know cold.Syllabus: truth tables for circuits including half and full adders; SR and JK flip-flops as storage elements; Boolean algebra and De Morgan's laws; Karnaugh maps
Next Paper 3
91%
9 in 10
Marks a paper
8
11% of the paper · 65% of the topic
Asked in
30 / 32
Paper 3 sittings · 30 questions
Last asked
May/Jun 2026
9618/33 · Q6 · 8 marks · 11-series streak
Asked in 30 of 32 Paper 3 sittings — nearly every paper.
About 8 marks a paper (11% of Paper 3; 65% of the topic's marks across its 2 bullets).
Last asked May/Jun 2026 · 9618/33 · Q6 (8 marks) — in the most recent series.
Asked in each of the last 11 series.
Usually “Complete” or “Write”: you must produce something — code, a diagram, a table — practise doing it, not reading it.
Biggest chunk of marks so far: 10 in Oct/Nov 2024 · 9618/31 · Q7.
It is examined almost entirely as AO2 (Apply & analyse, 79%) — you must apply it to the given data or scenario — work it out, trace it, explain it in context.
Last 12 sittings→ Steady
Assessment objectives
AO1 21%
AO2 79%
AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate
Complete90%
Write83%
Draw73%
Show57%
Practise its 30 questions Biggest: 10 marks · Oct/Nov 2024

13% of the topic's marks sit in question parts that belong to another topic (scenario questions cross sections) or that no bullet claims; they count for the topic, not for a bullet.

Marks a paper, year by year

212223242526

By exam series

May/Jun18/18 · 14.3 mk
Oct/Nov14/14 · 12.9 mk

Practise 58 real questions Smart Notes Quiz Flashcards Every topic on the Statometer

What you need to know2syllabus §15.1, §15.2

15.1Processors, parallel processing and virtual machines — RISC vs CISC and interrupt handling; pipelining; SISD, SIMD, MISD, MIMD; massively parallel computers; virtual machines and their limits
15.2Boolean algebra and logic circuits — truth tables for circuits including half and full adders; SR and JK flip-flops as storage elements; Boolean algebra and De Morgan's laws; Karnaugh maps

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Infographics6draw these the way the examiner expects · download as PNG

Half adder & full adder

SR & JK flip-flops

Karnaugh maps & Boolean algebra

RISC vs CISC & pipelining

Parallel processing & virtual machines

From logic circuit to truth table

O LevelASA2

Browse all infographics →

Key terms16use these exact words in the exam

RISCCISCpipeliningSISDSIMDMISDMIMDmassively parallelvirtual machinehypervisorhalf adderfull adder flip-flopBoolean algebraDe MorganKarnaugh map

Dotted terms are defined in the glossary.

Code help2referenced to the Cambridge pseudocode guide

Pipelining: what runs when

text

Cycle:   1    2    3    4    5    6
Instr 1: F    D    E
Instr 2:      F    D    E
Instr 3:           F    D    E
Instr 4:                F    D    E

4 instructions in 6 cycles instead of 12. A branch at Instr 2 would flush Instr 3–4.

Half adder and full adder as functions (§15.2)

pseudocode §8.2 functions Run in Playground

FUNCTION XOR(A : BOOLEAN, B : BOOLEAN) RETURNS BOOLEAN
   RETURN (A OR B) AND NOT (A AND B)
ENDFUNCTION
 
PROCEDURE FullAdder(A : BOOLEAN, B : BOOLEAN, Cin : BOOLEAN)
   DECLARE S1, C1, Sum, Cout : BOOLEAN
   S1 ← XOR(A, B)
   C1 ← A AND B
   Sum ← XOR(S1, Cin)
   Cout ← C1 OR (S1 AND Cin)
   OUTPUT A, " ", B, " ", Cin, " -> Sum ", Sum, " Carry ", Cout
ENDPROCEDURE
 
CALL FullAdder(TRUE, TRUE, FALSE)
CALL FullAdder(TRUE, TRUE, TRUE)

Boolean Algebra & K-map Lab35real Paper 3 questions — K-maps, De Morgan's laws, adders, flip-flops — solved and practised

Truth table, 6 ones → B.D + B̅.C̅.D̅
June 2025 Q5: write the sum-of-products (2), complete the K-map (2), loop it (2), write the simplified sum-of-products (2).
A2Truth table → K-map 9618 §15.2
Open
Truth table → A.D + B̅.D → D.(A + B̅)
Nov 2024 Q7, all five parts: sum-of-products (3), K-map (2), loops (2), simplified sum-of-products (2), simplest form by Boolean algebra (1).
A2Truth table → K-map 9618 §15.2
Open
Truth table → C̅.D + C.D̅ (no further simplification)
Nov 2024 Q6: eight ones, two loops of four that cannot be factorised — the answer stays as a sum-of-products.
A2Truth table → K-map 9618 §15.2
Open
Truth table → A̅.B̅ + A̅.C → A̅.(B̅ + C)
June 2023 Q9: two overlapping loops of four, then one factorising step for the simplest form.
A2Truth table → K-map 9618 §15.2
Open
Truth table → A.B + A.D → A.(B + D)
Nov 2021 Q7: the examiners noted students simplified when the sum-of-products was asked for — write all six products first.
A2Truth table → K-map 9618 §15.2
Open
Truth table → B + C̅.D
June 2026 Q7: a loop of eight (B) plus a loop of four wrapping the top and bottom rows.
A2Truth table → K-map 9618 §15.2
Open
Truth table → B̅.C + B.C̅.D̅
June 2025 Q3: a loop of four in the bottom rows plus a loop of two — the two 1s in the top row are adjacent in the middle columns.
A2Truth table → K-map 9618 §15.2
Open
Three-variable truth table (A rows, BC columns)
The 3-input map Cambridge draws with A down the side and BC along the top — a loop of four and a loop of two.
A2ASTruth table → K-map 9618 §15.2
Open
Six products → A.C + B.C → C.(A + B)
June 2023 Q7: complete the K-map from the expression (2), loops (2), simplified sum-of-products (2), simplest form (1).
A2Expression → K-map 9618 §15.2
Open
Six products → B.C̅ + A.C̅ → C̅.(A + B)
Nov 2022 Q7: the examiners saw one loop drawn round all six 1s, or six loops of two — both wrong. Two loops of four.
A2Expression → K-map 9618 §15.2
Open
Three-variable K-map → A + B̅
June 2024 Q6(c): six products of A, B, C on the 2 × 4 map; two loops of four give A + B̅.
A2Expression → K-map 9618 §15.2
Open
Three-variable K-map → B + C̅ (wrapping loop)
June 2024 Q6(c) variant 2: one loop of four wraps the outer columns (C̅) and one covers the middle two (B).
A2Expression → K-map 9618 §15.2
Open
Four products → A̅.B + B.C̅ + A.B̅.C
Nov 2025 Q6(b): three loops — two of two and one lone 1 that stays a full three-literal product.
A2Expression → K-map 9618 §15.2
Open
The four corners are one loop → B̅.D̅
Top-left, top-right, bottom-left and bottom-right cells are all adjacent on a K-map — one loop of four.
A2Expression → K-map 9618 §15.2
Open
K-map given → A̅.C̅.D + B.D + A.C
Nov 2025 Q6(a): three loops for three marks — max 2 if any incorrect loop is drawn.
A2Expression → K-map 9618 §15.2
Open
K-map given → A.B + B.D + C.D
June 2026 Q6(c): a loop of four (A.B), a loop of four (C.D) and a loop of four (B.D) overlapping both.
A2Expression → K-map 9618 §15.2
Open
(A + B + C̅)‾ + B̅.C → B̅.C
June 2026 Q6(b): De Morgan's, double negation, then absorption — one mark for the answer, up to two for the laws.
A2De Morgan's laws 9618 §15.2
Open
(A.B.C.D)‾ + A̅.D̅ → A̅ + B̅ + C̅ + D̅
June 2026 Q7(b): break the four-term bar, then the A̅.D̅ term is absorbed.
A2De Morgan's laws 9618 §15.2
Open
(A + B)‾.(A.B̅ + B.C)‾ → A̅.B̅
June 2025 Q7(c), 4 marks: De Morgan's, then idempotent / distributive / absorption laws. The scheme also accepts (A + B)‾.
A2De Morgan's laws 9618 §15.2
Open
Bar over three barred products → A.(B + C) + B.D
Nov 2022 Q8(c): a double-bar expression. The examiners' common error: splitting the bar but leaving AND as AND.
A2De Morgan's laws 9618 §15.2
Open
Apply De Morgan's to (A + B + C)‾
Nov 2023 Q7(b): the 3-input NOR gate as an expression — one line, one mark.
A2De Morgan's laws 9618 §15.2
Open
(A + B̅ + C̅)‾ + (B + C̅)‾ → C.(A̅ + B̅)
Nov 2025 Q6(b): De Morgan's twice, then the distributive and redundancy laws.
A2De Morgan's laws 9618 §15.2
Open
X̅.Y.Z + X̅.Y̅.Z + X → X + Z
Nov 2023 Q7(c): distributive, complement, identity, then the redundancy law to finish.
A2Boolean algebra 9618 §15.2
Open
Four products → A.D̅
Nov 2023 Q6(b): factor out A.D̅, then B.(C + C̅) + B̅.(C + C̅) collapses to 1 — the model working in the mark scheme.
A2Boolean algebra 9618 §15.2
Open
Absorption: A + A.B + A.B̅.C
Two absorptions in a row — everything with an A in it collapses into A.
A2Boolean algebra 9618 §15.2
Open
Redundancy: A.B + A̅.C + B.C
The consensus term B.C is covered by the other two — the K-map shows it as a loop you do not need.
A2Boolean algebra 9618 §15.2
Open
XOR as a sum-of-products
A ⊕ B = A.B̅ + A̅.B — the half adder's sum output written in Boolean algebra.
A2ASO LevelBoolean algebra 9618 §15.2
Open
Circuit with working columns P, Q, R, S
June 2024 Q6(a): P = A̅, Q = B.C, R = P NAND Q... build the working columns in gate order, then Z. One mark for the working, one per half of Z.
A2ASO LevelCircuit → truth table 9618 §15.2
Open
3-input NAND circuit → truth table
Nov 2023 Q6(a): a 3-input NAND feeding the output — the syllabus says gates “may have more than two inputs”.
A2ASCircuit → truth table 9618 §15.2
Open
3-input NOR gate
Nov 2023 Q7(a): X = (A + B + C)‾ — only one row of the truth table is 1.
A2ASCircuit → truth table 9618 §15.2
Open
Four working columns and an XOR
Nov 2025 Q6(a) style: an XOR, a NAND and an OR feeding a final AND — eight rows, four working columns.
A2ASO LevelCircuit → truth table 9618 §15.2
Open
Half adder: name it, state Sum and Carry
June 2022 Q6: two inputs A and B, outputs E (sum = A ⊕ B) and F (carry = A.B). 5 marks for the table, the name and the purposes.
A2Half & full adders 9618 §15.2
Open
Full adder: working columns, Sum and Carry as sums-of-products
June 2021 Q7: complete P, Q, R, then Y (sum) and Z (carry); name the circuit; write Y and Z as sums-of-products — NOT simplified.
A2Half & full adders 9618 §15.2
Open
SR flip-flop: draw it, label S and R, find the invalid state
Nov 2022 Q8: two NAND (or two NOR) gates, each output fed back to the other's input; purpose — to store one bit.
A2Flip-flops 9618 §15.2
Open
JK flip-flop: the toggle state SR cannot handle
J = K = 1 toggles the output on the clock pulse — no invalid combination, which is why JK replaces SR.
A2Flip-flops 9618 §15.2
Open

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Quiz: Hardware & Virtual Machines (72)🃏 Flashcards: mix this topic (76)🧬 RISC vs CISC & pipelining (15)🧵 Parallel processing — Flynn's taxonomy (13)📦 Virtual machines (12)🧮 Boolean algebra & De Morgan's laws (16)🗺️ Karnaugh maps, adders & flip-flops (20)Past-paper questions (58)🗺️ Boolean Algebra & K-map Lab 🔁 Adders & flip-flops ⚡ Logic Gates Lab 🚇 Pipelining & RISC/CISC

Everything for this topic — study hub

Statometer — what 32 real papers say about this topic and each of its 2 syllabus bullets

What you need to know2syllabus §15.1, §15.2

Video lectures20ZAK's YouTube channel · play here

RISC · CISC · Microprocessor Architectures · A Level

Pipelining · Four Basic Computer Architectures · Part 2 · SISD, SIMD, MISD, MIMD · A Level

Karnaugh Maps · Part 2 · K-maps · P3

Four Basic Computer Architectures · Part 1 · SISD, SIMD, MISD, MIMD · A Level

Karnaugh Maps · Part 1 · K-maps · P3

Virtual Machines · A Level

Infographics6draw these the way the examiner expects · download as PNG

Key terms16use these exact words in the exam

Code help2referenced to the Cambridge pseudocode guide

Boolean Algebra & K-map Lab35real Paper 3 questions — K-maps, De Morgan's laws, adders, flip-flops — solved and practised

Ready to check you know it?