Four books.
Every 9618 paper.
One book for each Cambridge AS & A Level Computer Science paper, written by ZAK the way the examiners mark — every worked answer checked by the site's own engines, every section a doorway into the free practice here. In print, or as an ebook you read right here.
No prices here — the admissions team confirms everything on WhatsApp. Everything on cswithzak.com stays free.
The series
One book for every paper.
Each cover is a heat map: every block is a syllabus section, sized by the marks it earns on the real papers. The book spends its pages the same way.
Book 1 · AS Paper 1
Theory Fundamentals
Everything Paper 1 asks — number systems to SQL — with every worked answer checked by the site's own engines.
Where the marks are on Paper 1
- §2.1 · ≈ 9.4 marks
- §3.1 · ≈ 7.8 marks
- §4.1 · ≈ 7 marks
8 chapters · sections 1–8 · 1 of 8 ready to read
Book 2 · AS Paper 2
Fundamental Problem-solving and Programming Skills
Pseudocode you can trust, the way Paper 2 marks it — traced, run and explained one step at a time.
Where the marks are on Paper 2
- §11.2 · ≈ 35.4 marks
- §11.3 · ≈ 12.4 marks
- §10.2 · ≈ 11 marks
5 chapters · sections 9–12 · 1 of 5 ready to read
Book 3 · A2 Paper 3
Advanced Theory
The A2 theory paper made calm: floating point by ZAK's booklet method, Boolean algebra line by line, BNF, AI graphs.
Where the marks are on Paper 3
- §19.1 · ≈ 9 marks
- §16.2 · ≈ 8.5 marks
- §15.2 · ≈ 8 marks
8 chapters · sections 13–20 · 1 of 8 ready to read
Book 4 · A2 Paper 4
Practical Programming
Paper 4 in Python, VB.NET and Java side by side — every program executed, every screenshot the way the evidence document wants it.
Where the marks are on Paper 4
- §20.1 · ≈ 38 marks
- §19.1 · ≈ 30.8 marks
- §20.2 · ≈ 8.6 marks
11 chapters · sections 19–20 (+ AS 9–12 skills) · Python, VB.NET, Java · 1 of 11 ready to read
Exam Heat from the CS with ZAK Statometer, data as of 2026-10-06. Every expected-marks figure is per sitting of the paper the book covers.
Two editions
On paper, or on this site.
Buy the one you want — they are sold separately. Either way, the website's free practice is one scan or one click away from every section.
Ebook
Read on cswithzak.com · 2 years
- Opens instantly, on up to three devices
- Highlights, notes and bookmarks that sync
- Mark yourself against every scheme, run the code in the labs
- New chapters arrive at no extra cost
Print edition
Printed in colour, 19 × 24.6 cm
- The whole book in your hands, in colour
- A QR code and short code beside every section
- Delivered by courier
Already bought the ebook? Redeem your access code — it unlocks the book for 2 years on up to three devices.
The ebook
A book that talks back.
The ebook isn't a PDF. It's the book rebuilt for the screen — questions you can mark, code you can run, and a teacher one selection away.
- Highlight and annotateFour colours and your own notes, synced to every device you read on.
- Mark yourselfAnswer, then open the scheme and tick each point you made. The book keeps your score.
- Run the codeEvery program opens in the site's own labs, ready to run, trace and change.
- Ask Z about any lineSelect a sentence and Ask Z explains it, then checks you understood.
- Exam Heat as you readEach section shows how often it is set, how likely it is and the marks it earns.
- Read your wayText size, paper, sepia or night, serif or sans, extra line spacing — saved on your device.
8.1 Why a database?
A flat file keeps every record in one table, so the same customer's address is typed again on every order. When one copy changes and the others don't, the data is inconsistent — and that is the mark scheme's word.
3 Explain · AO2 · §8.1 [3]
Explain two problems of storing this data in a flat file.
- ✓Data redundancy — repeated
- ✓Inconsistent after an update
- Wasted storage space
EXAM HEAT · §8.1
Banker · ≈ 6 marks
KEY TERM
Redundancy — the same data stored more than once.
Ask Z
“Why does redundancy cause inconsistency?”
What's inside
Built the way the exam marks.
Every chapter is one syllabus section: an opener with its Exam Heat, complete notes, original practice questions in three tiers, Cambridge-style mark schemes and a one-page wrap-up.
Exam Heat
Every chapter opens with the Statometer's numbers: how often the topic is set, how likely it is next time and the marks it is worth.
A doorway on every spread
A QR code and a short code take you straight to the quiz, flashcards, past-paper questions or lab for that page.
Examiner's Eye
What examiners keep saying about real answers, in plain words — where the marks were lost and how to keep them.
Mark Ladder answers
Worked answers built one mark at a time, so you see exactly which line earns which tick.
Trace-it pages
Code beside its trace table on one spread. In Book 4: pseudocode, Python, VB.NET and Java in four columns.
Misconception Museum
The wrong ideas students bring into the exam — each one shown, taken apart and tested, never printed on its own.
Retrieval and spacing
Recall grids reach back one and three chapters, and mixed sets bring old topics round again before you forget them.
Command-word coach
Explain, describe, justify, evaluate: what each word wants, with the assessment objective and marks on every question.
One diagram language
The same colour-blind-safe shapes across all four books, and an infographic spread in every chapter.
Core, Stretch, Extension
Every question carries its tier, so you know where to start and how far to push. A Teacher Edition sits alongside.
Accessible editions
Large print, dyslexia-friendly and accessible digital editions are planned for every book.
A pack for schools
Teachers can ask for class sets and a sample booklet with one chapter from each book.
The book talks to the website
Beside every section of the printed book is a QR code and a short code. Scan it, or type it here, and you land on the quiz, flashcards, past-paper questions or lab for exactly that page.
Book · chapter · item — B1·8 is Book 1 chapter 8, B1·8·3 its third section, B1·8·Q the quiz, B1·8·F the flashcards.
Workbooks to write in
Each book has a companion workbook with the same chapters: A4, black and white, with drills, trace tables, fix-the-mistake and mark-it-yourself pages. Short answers sit at the back; full mark schemes are online behind each QR code.
- W1Theory Fundamentals Workbook
- W2Problem-solving and Programming Skills Workbook
- W3Advanced Theory Workbook
- W4Practical Programming Task Book
Schools can ask for a photocopy licence for their own classes.
For schools and teachers
Printed class sets, ebook access codes for a whole class, the workbooks with a photocopy licence, and a free sample booklet with one chapter from each book. The Teacher Edition adds answers in the margin and lesson notes.
FAQ
Before you ask.
How do I buy a book?
Message the admissions team on WhatsApp with the book and the edition you want. They confirm availability, payment and delivery. Nothing is sold or paid for on this site.
How does the ebook work?
You read it here, on cswithzak.com, signed in with your free account. After payment the admissions team sends you an access code; redeem it on My books and the whole book opens for 2 years from that day, on up to three of your devices.
Can I download the ebook or print it?
No. The ebook is read on the website only — there is no file to download, and printing is switched off. That protects the work for everyone who bought it. Your own highlights and notes can be downloaded at any time.
Does the printed book come with the ebook?
No — they are sold separately, so you only pay for the edition you want.
What if I change phone or laptop?
Sign the old device out of your books on My books and open the book on the new one. A device you haven't used for 60 days drops off by itself.
Can I read before I buy?
Yes. One whole chapter of every book is free to read here, with all its questions and mark schemes — no account needed. The free chapters go up first, as each is finished and reviewed.
Is the website still free?
Yes. Everything on cswithzak.com stays free: notes, past papers, quizzes, labs and Ask Z. The books are written to sit beside it — every section links to the free practice for it.
Do schools get class sets?
Yes. A school can order printed class sets or ebook access codes for a whole class, and ask for the sample booklet with one chapter from each book. Ask the admissions team on WhatsApp.
