You have covered the foundations. This final section gives you a taste of actual A Level questions, tells you what to expect in the first few weeks, and collects your baseline submission.
✓
You have done the work.
Working through these sections has put you ahead of where most students start. The A Level will go significantly deeper than anything here, but you now have the mental models that make the deeper content land properly. Binary, logic, architecture, Python: none of those will be cold starts in September.
A taste of A Level questions
OCR H446 has two written papers and a programming project (NEA). The written papers test your ability to explain, analyse, and apply concepts, not just recall them. Here are four questions in the style of the actual exam, one from each of the foundation sections you have just completed.
Attempt each question on paper before revealing the mark scheme. Exam technique matters: look at the number of marks available and make sure you make that many distinct points.
Number systems6 marks
(a)Convert the denary number 157 into 8-bit binary. Show your working. [2]
(b)Convert your answer to part (a) into hexadecimal. [1]
(c)Represent -57 in 8-bit two's complement. Show your working. [3]
Mark scheme
(a)10011101 [1 mark for correct binary, 1 mark for correct working shown: 128+16+8+4+1=157]
(a)Describe the role of the Program Counter (PC) in the fetch-decode-execute cycle. [2]
(b)Explain the difference between the address bus and the data bus. [2]
(c)Explain why cache memory improves the performance of a computer system. [2]
Mark scheme
(a)Holds the memory address of the next instruction to be fetched [1]; is copied to the MAR at the start of each fetch / is incremented after each fetch so the next instruction in sequence is fetched [1]
(b)The address bus carries the memory address the CPU wants to read from or write to [1]; the data bus carries the actual data or instruction being transferred [1]. Accept: address bus is unidirectional / data bus is bidirectional as a second mark point.
(c)Cache is faster to access than main memory / RAM [1]; frequently used data or instructions are stored in cache so they can be retrieved quickly without accessing the slower RAM, reducing the average time to fetch data [1]
Programming5 marks
(a)Write a Python function called find_max that takes a list of integers as a parameter and returns the largest value without using Python's built-in max() function. [3]
(b)Explain what is meant by the scope of a variable, and give one reason why local scope is preferable to global scope. [2]
Mark scheme
(a)Correct function definition with parameter [1]; iterates through the list comparing values [1]; returns the correct maximum value [1]. Example solution:
def find_max(numbers):
current_max = numbers[0]
for n in numbers:
if n > current_max:
current_max = n
return current_max
(b)Scope is the part of the program where a variable can be accessed / where a variable exists [1]; local scope means the variable only exists within its function, preventing it from being accidentally changed elsewhere in the program / making functions easier to test independently / reducing naming conflicts [1]
What to expect in September
📚 The course structure
OCR H446 has two written papers (each 2h30, worth 40% each) and a programming project called the NEA (20%). The NEA runs through Year 13 and is the part of the course where you get to choose what to build.
💻 First lessons
We will start with computer architecture and data representation in depth: this bridging content gives you a head start but the A Level goes much further. Python will run in parallel throughout Year 12 as we work towards the NEA.
📄 What to bring
A notebook for diagrams and worked examples (screens are not always ideal for truth tables and circuit drawings). A willingness to attempt problems before asking for the answer: the struggle is part of the learning.
🤔 The step up
A Level CS is harder than GCSE, and the jump from Year 12 to Year 13 is significant. The students who do best are the ones who stay curious between lessons: read around topics, watch videos, write small programs. Treat it as a subject, not just a set of lessons.
Recommended resources
These are the resources we use and recommend throughout the course. All are free.
Before September, please complete and submit the short form below. It has three parts: a few questions on the topics from this site, your Python mini-project code, and a short written response. It takes about 15 minutes and helps us plan the first few lessons around where everyone actually is.
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This is not assessedThe baseline submission is not marked and does not count towards your grade. It is purely so we know where to start in September. Answer honestly: if you found something difficult, say so. That information is more useful than a polished answer that hides uncertainty.
Baseline task: submit before September
Complete all three sections. The Python section asks you to paste the code from your mini-project.