AQA A-LEVEL COMPUTER
SCIENCE: COMPUTER
ARCHITECTURE EXAM 2026 WITH
350 QUESTIONS AND VERIFIED
CORRECT ANSWERS | ALREADY
GRADED A+ | GUARANTEED PASS |
AQA COMPUTER SCIENCE EXAM
2026 [LATEST VERSION]
Define subsystem (3 marks)
The architecture of a computer system consists of subsystems (1). These are
independent (1), and either internal or external (1).
State the 4 internal subsystems/components of the computer
- Central processing unit (CPU)
- Main memory (RAM)
- I/O Controllers (Input/Output)
- The system bus
State 3 examples of external subsystems/components
,- A keyboard
- A computer monitor
- A printer
- A magnetic hard drive
State what external subsystems/components are also known as
Peripherals or peripheral devices
Define peripheral (3 marks)
An external hardware device (1) that is connected to the computer system (1)
but not under the direct control of the processor (1).
The memory buffer register connects to the ... bus
Fill in the blank (1 mark)
The memory buffer register connects to the data bus
State 3 reasons why peripheral devices are not connected directly to the CPU
- Each peripheral operates in a different way
- It is not sensible to design a processor to control every possible peripheral
- A new type of peripheral would require the processor to be redesigned
- Peripherals may operate at a different voltage from the processor
- Peripherals will usually operate at a slower rate than the processor, requiring
buffering
,Draw a simplified diagram of the Von Neumann architecture, including:
- The CPU
- Main memory
- The buses
- A keyboard
- A keyboard input controller
- A visual display unit (VDU)
- A VDU Controller
- Secondary storage
- A (disk) I/O Controller
3 marks
1 mark for correct bus connections (connecting directly between cpu and
controllers ONLY)
1 mark for connecting the keyboard and the VDU to their respective controllers
ONLY
1 mark for not drawing any connections other connections than those specified
in the first and second marking points
Describe what main memory consists of (3 marks)
Contiguous blocks of read/write (1), randomly accesible (1) storage locations
(1)
Describe the role of main memory in the execution of computer programs (2
marks)
Any two of:
, - Main memory stores the instructions to be executed (and any data required by
those instructions)
- Main memory returns the instructions / data / value stored in a memory
location (specified on the address bus) (using the data bus)
- Program is transferred from secondary storage into main memory (if program
not already in main memory) when program execution is requested
- Main memory stores any value / data resulting from the execution of the
program;
Define word (3 marks)
A fixed size (1) group of bits (1), used by a processor as its natural unit of data
(1)
Define word length (1 mark)
The size of a word in bits
State what main memory is a store for
Words
The size of a word in main memory is fixed. True/False?
True
State how a particular location/word in RAM is located
With a unique integer address
SCIENCE: COMPUTER
ARCHITECTURE EXAM 2026 WITH
350 QUESTIONS AND VERIFIED
CORRECT ANSWERS | ALREADY
GRADED A+ | GUARANTEED PASS |
AQA COMPUTER SCIENCE EXAM
2026 [LATEST VERSION]
Define subsystem (3 marks)
The architecture of a computer system consists of subsystems (1). These are
independent (1), and either internal or external (1).
State the 4 internal subsystems/components of the computer
- Central processing unit (CPU)
- Main memory (RAM)
- I/O Controllers (Input/Output)
- The system bus
State 3 examples of external subsystems/components
,- A keyboard
- A computer monitor
- A printer
- A magnetic hard drive
State what external subsystems/components are also known as
Peripherals or peripheral devices
Define peripheral (3 marks)
An external hardware device (1) that is connected to the computer system (1)
but not under the direct control of the processor (1).
The memory buffer register connects to the ... bus
Fill in the blank (1 mark)
The memory buffer register connects to the data bus
State 3 reasons why peripheral devices are not connected directly to the CPU
- Each peripheral operates in a different way
- It is not sensible to design a processor to control every possible peripheral
- A new type of peripheral would require the processor to be redesigned
- Peripherals may operate at a different voltage from the processor
- Peripherals will usually operate at a slower rate than the processor, requiring
buffering
,Draw a simplified diagram of the Von Neumann architecture, including:
- The CPU
- Main memory
- The buses
- A keyboard
- A keyboard input controller
- A visual display unit (VDU)
- A VDU Controller
- Secondary storage
- A (disk) I/O Controller
3 marks
1 mark for correct bus connections (connecting directly between cpu and
controllers ONLY)
1 mark for connecting the keyboard and the VDU to their respective controllers
ONLY
1 mark for not drawing any connections other connections than those specified
in the first and second marking points
Describe what main memory consists of (3 marks)
Contiguous blocks of read/write (1), randomly accesible (1) storage locations
(1)
Describe the role of main memory in the execution of computer programs (2
marks)
Any two of:
, - Main memory stores the instructions to be executed (and any data required by
those instructions)
- Main memory returns the instructions / data / value stored in a memory
location (specified on the address bus) (using the data bus)
- Program is transferred from secondary storage into main memory (if program
not already in main memory) when program execution is requested
- Main memory stores any value / data resulting from the execution of the
program;
Define word (3 marks)
A fixed size (1) group of bits (1), used by a processor as its natural unit of data
(1)
Define word length (1 mark)
The size of a word in bits
State what main memory is a store for
Words
The size of a word in main memory is fixed. True/False?
True
State how a particular location/word in RAM is located
With a unique integer address
