Computing Theory

What is the purpose of the Control Unit (CU)?

It sends signals to other components to coordinate the Fetch-Decode-Execute (FDE) cycle.

What is the role of the Arithmetic Logic Unit (ALU)?

It carries out calculations (+, -, *, /) and logical comparisons.

What are registers?

Small, fast memory cells within the CPU used for temporary storage of data and interim results.

What is the function of the Address Bus?

It carries the memory location of a piece of data or an instruction from the CPU to RAM (it is uni-directional).

What is the function of the Data Bus?

It carries a piece of data or an instruction between the CPU and memory (it is bi-directional).

What is the function of the Control Bus?

It carries read/write signals to coordinate the FDE cycle.

What happens during the 'Fetch' stage of the FDE cycle?

The memory address of the next instruction is placed on the address bus, and the instruction is moved from RAM to the CPU via the data bus.

What determines the clock speed of a CPU?

The frequency of pulses sent by the clock

How do you convert Hexadecimal to Binary?

Convert each Hex digit into its 4-bit binary equivalent (e.g., A = 1010, F = 1111).

How do you convert Binary to Hexadecimal?

Group the binary bits into sets of four (starting from the right) and convert each group into its hex equivalent.

What is a Logical Shift Left?

Moving all bits to the left and filling the empty right-hand spots with 0s

What is a Logical Shift Right?

Moving all bits to the right and filling the empty left-hand spots with 0s

What is an Arithmetic Shift Right?

Moving bits to the right while preserving the sign bit (the leftmost bit) to maintain the value of a negative number in two's complement.

What is Two's Complement used for?

A method used to represent signed (positive and negative) integers in binary.

What is secondary storage?

Long-term, non-volatile storage used for programs and data.

How does Magnetic storage work?

A drive with moving parts that uses magnetic states on a chemical coating to represent 0s and 1s.

How does Solid State (SSD) storage work?

It stores data as electric charges on NAND flash memory with no moving parts.

What is the purpose of an Operating System (OS)?

To manage hardware and software, including file management, process management (paging), and peripheral management.

What is virtual memory?

A technique where inactive processes are moved from RAM to secondary storage to free up space when RAM is full.

What is decomposition?

Breaking down a complex problem into smaller, more manageable subproblems.

What is abstraction?

Removing or hiding unnecessary details from a problem to focus on the core issue.

What is the difference between a function and a procedure?

A procedure completes a task

How does a Linear Search work?

It starts at the first position and compares each item with the target until a match is found or the end of the list is reached .

How does a Bubble Sort work?

It compares adjacent values and swaps them if they are in the wrong order, repeating until a full pass occurs with no swaps.

What is Phishing?

A social engineering attack where deceptive messages are used to trick victims into revealing sensitive data.

What is shoulder surfing?

Watching someone as they enter sensitive information, such as a PIN or password, to steal it.

What is the purpose of Penetration Testing?

To perform an authorised attack on a network to identify and fix security vulnerabilities.

Why is software patched?

To provide updates that fix security bugs/vulnerabilities and prevent exploitation.

What is an environmental impact of technology manufacture?

Mining for raw materials and the high energy/water consumption required for component production.

How can you reduce the environmental impact of technology?

By extending the replacement cycle (repairing, reconditioning, or donating devices) to reduce e-waste and manufacturing demand.