The Jigsaw–Pack Architecture
Every topic in this vault has exactly two notes. They hold the same material, organised for two different jobs.
🧩 Jigsaw — what could be asked
The syllabus, rebuilt bullet by bullet, with every tested angle mapped onto it. Read it to find out where the marks live and what has never been asked.
🎯 Pack — answering it under timed conditions
The same concepts turned into exam questions with full mark-scheme answers, collapsed so you can self-test. Use it to rehearse.
Why two notes and not one
A revision note that mixes “here is the content” with “here is a question on it” does neither job well. You cannot skim it for coverage, and you cannot test yourself on it without seeing the answers.
Splitting them means the Jigsaw is a map and the Pack is a drill. They mirror each other section by section, so any concept can be followed from one to the other.
The Jigsaw
The Jigsaw walks the syllabus in order — 8.1.1, 8.1.2, 8.1.3 and so on — and under each bullet places every distinct concept that has been, or could be, examined. Each concept gets one callout, and the callout’s type tells you its exam status.
Already examined in 9618
Tested in a 9618 paper, 2021 onwards. The mark-scheme points are given, followed by the question ID of the most recent appearance, in the format the Legend PDFs use:
9618_w25_qp_13_sc_5.b.
9608 only — not yet in 9618
Tested under the old 9608 syllabus (pre-2021), but the wording is still inside the current 9618 syllabus. Fair game — and often a genuine content gap rather than just a format one. Latest 9608 question ID given.
Not yet tested — inference
In the syllabus, but never asked in either series — or only ever asked in a much narrower form. Every one carries a justification for why it is a plausible question, and a suggested tariff.
From the Save My Exams notes
Content the SME revision notes teach that no past question covers. Useful for understanding; weigh it against the mark schemes before trusting it in an answer.
No old-syllabus safety net
Flags a sub-topic that is new in 9618 with no 9608 questions at all, so there is nothing to fall back on. Currently: AI (7), embedded systems (3), PROM/EPROM/EEPROM (3), bit manipulation (all of 4.3) and IDE features (5.2.4).
Reading notes
Occasional notes about the shape of a question rather than its content — fixed tariffs, block marking, command-word traps.
How to read the question IDs
9618_w25_qp_13_sc_5.b → syllabus 9618 · session w25 (Winter 2025) · qp_13 (paper 13) · sc_5.b (question 5b).
s = summer (May/June), w = winter (Oct/Nov).
The Pack
The Pack mirrors the Jigsaw. Every concept becomes a !question callout containing a collapsible answer, so the question can be attempted before the answer is revealed.
> [!question] 9618 | Describe the purpose of an OS in a computer [5]
>
> Describe the purpose of an Operating System in a computer system.
>
>> [!success]- Answer — 7 points for 5 marks
>> - To provide a **user interface** … so the user can communicate with the hardware
>> - To **manage memory** … so data can be stored and multitasking is possible
>> - …
>>
>> *Latest: `9618_s25_qp_11_sc_6.b`*The title line
prefix | rewritten question [marks]
- 9618 | — the highest tariff this concept has ever carried in a 9618 paper. If November 2025 asked it for 2 marks and June 2022 for 4, the Pack uses 4.
- 9608 | — the same rule applied to 9608 tariffs.
- Inferred | — never tested; the tariff is estimated from how 9618 marks comparable questions.
- SME | — drawn from the Save My Exams notes, tariff estimated the same way.
The wording is rewritten generic exam-style, not the original past-paper scenario — so you are testing the concept rather than remembering one particular context.
The answer
Answers aim for the maximum tariff plus two spare points, because mark schemes routinely list more credit-worthy points than the tariff allows. The newest mark scheme leads; older ones fill the gaps.
- One bullet = one mark.
- A bullet beginning
…is an expansion of the point above it, not a separate mark — this is how Cambridge marks “point plus expansion” questions. - Capping rules are stated wherever they exist: max 2 for each, mark in pairs, no mark for the choice.
- The question ID at the foot is the paper the answer was built from.
How to actually use them
- Map first. Read a Jigsaw section and note which callouts are
!success— those are the questions that keep coming back. - Drill. Open the matching Pack section, cover the answer, write a full answer to the tariff, then expand the callout and mark yourself against the bullets.
- Mind the
!infoentries. They are the untested corners of the syllabus. In a subject where examiners cycle through bullets, these are where next year’s unfamiliar question is most likely to come from. - Treat
!warningentries as real. 9608 questions are the same syllabus content in an older format. Chapter 6 has 31 of them; chapter 4 has none at all.
What memorising a Pack will not do
Learning every Pack answer by heart does not guarantee full marks. Mark schemes award contextual application — points tied to the scenario in front of you — and the same concept is set at different tariffs with different command words. The Pack teaches you the content and the shape of the answer; timed past papers teach you to apply it. Use both.
Conventions used throughout
| Convention | Meaning |
|---|---|
| Bold inside an answer | The exact word or phrase the mark scheme requires |
// | ”or” — an equally acceptable alternative wording |
… starting a bullet | An expansion of the bullet above, not a separate mark |
[n] in a title | The mark tariff being answered to |
Latest: id | The most recent paper this concept appeared in |
Source material
Everything traces back to the Legend archive — the full 9618 and 9608 question banks sorted by syllabus bullet — plus the 2026 syllabus PDF and the Save My Exams notes. Where a claim is an inference rather than a mark-scheme point, the note says so explicitly.