1.1 Hardware

Question 1

What is the CPU?

Answer 1

The core of the computer.

Question 2

What are the main components of the CPU?

Answer 2

1. Control unit (CU)
2. Arithmetic logic unit (ALU)
3. Registers

Question 3

What is the purpose of the CU?

Answer 3

Manages and coordinates CPU operations.

Question 4

What is the purpose of the ALU?

Answer 4

Performs arithmetic and logical operations.

Question 5

What are registers?

Answer 5

Fast storage locations within the CPU.

Question 6

What is the Current instruction register (CIR)?

Answer 6

Holds the instruction currently being executed.

Question 7

What is the memory address register (MAR)?

Answer 7

Stores the address of the memory location to be accessed.

Question 8

What is the memory data register (MDR)?

Answer 8

Contains data being transferred to or from memory.

Question 9

What is the Accumulator?

Answer 9

Stores intermediate results of arithmetic and logical operations.

Question 10

What is the address bus?

Answer 10

Carries memory location addresses.

Question 11

What is the data bus?

Answer 11

Transfers data between CPU and memory.

Question 12

What is Random Access Memory (RAM)?

Answer 12

Volatile main memory.

Question 13

What is Von Neumann Architecture?

Answer 13

Common processor design with shared storage for data and instructions; less expensive but slower.

Question 14

What is Harvard architecture?

Answer 14

Processor design with separate storage for data and instructions; more expensive but faster.

Question 15

What is the FDE cycle?

Answer 15

The Fetch-Decode-Execute (FDE) cycle, also known as the instruction cycle, is a fundamental process in computer architecture that describes how a computer’s central processing unit (CPU) operates. This cycle is continuously repeated as the computer processes instructions.

Question 16

What happens during the fetch stage?

Answer 16

• The CPU retrieves the next instruction from the computer’s memory.
• The Program Counter (PC) contains the address of the next instruction to be fetched.
• This address is copied into the Memory Address Register (MAR).
• The instruction at that memory address is then copied into the Memory Data Register (MDR).
• Finally, the instruction is placed in the Current Instruction Register (CIR).
• The Program Counter is then incremented to point to the next instruction.

Question 17

What happens during the decode stage?

Answer 17

• The Control Unit (CU) of the CPU interprets the instruction in the CIR.
• It determines what operation needs to be performed (e.g., addition, subtraction, data movement).
• The CU identifies the memory locations or registers that contain the required data (operands).
• It also determines where the result should be stored.

Question 18

What happens during the execute stage?

Answer 18

• The CPU carries out the instruction that was decoded.
• If it’s an arithmetic or logical operation, the Arithmetic Logic Unit (ALU) performs the calculation.
• For data movement operations, data is transferred between registers or between memory and registers.
• The result of the operation is stored in the designated location (usually a register or memory address).

Question 19

What factors effect computer performance?

Answer 19

Clock speed, Cache size, Number of cores

Question 20

What is the clock speed?

Answer 20

An alternating pulse of low and high voltage, measured in Hz/GHz. A higher clock speed results in faster processing.

Question 21

What is cache memory?

Answer 21

A fast but small-capacity set of locations close to the processor. It stores frequently used instructions and data. Measured in megabytes, cache memory is more expensive than RAM.

Question 22

What are the different levels of cache memory and how do they effect performance?

Answer 22

Level 1 cache: The smallest and fastest cache, integrated into the circuitry of each core.

Level 2 cache: Often shared by cores, it’s larger but slower than L1 cache.

Level 3 and 4 cache: Slower than L2 cache but larger, located on the processor or nearby on the motherboard.

Question 23

How do the Number of cores effect the performance?

Answer 23

Number of cores: Each core contains a Control Unit (CU), Arithmetic Logic Unit (ALU), special registers, and local cache. As each core can run its own Fetch-Decode-Execute (FDE) cycle, more cores allow for more instructions to be processed simultaneously.

Question 24

What is a input device?

Answer 24

A device that sends data to the computer for processing.

Question 25

What is a output device?

Answer 25

A device that presents the results of the processing.

Question 26

What does the term contemporary mean?

Answer 26

Relating to modern or present-day technology.

Question 27

What are the 3 types of computer secondary storage?

Answer 27

Magnetic, Optical, Solid state

Question 28

What does media mean in terms of storage?

Answer 28

Media: The physical component where data is actually stored.

Question 29

What is a Hard disk drive?

Answer 29

Hard disk drive (HDD) – A form of secondary storage that uses magnetism to write and read data based on positive or negative charges.

Question 30

What are the different components of a Hard disk drive?

Answer 30

• Read and write head – Writes data by applying magnetic charges to different sectors and reads data by detecting these charges. The different charges represent binary 1s or 0s.
• Disk – Made of metal or coated with a magnetic material. Several disks are stacked within the HDD.
• Actuator arm – Moves the read and write head across the disk, allowing access to the entire surface.

Question 31

What is Defragmentation?

Answer 31

Defragmentation – A process used when an HDD has been heavily used and data becomes fragmented, slowing access speeds. Defragmentation software reorganises and rewrites the data to improve performance.

Question 32

Properties of Magnetic storage?

Answer 32

• Brittle
• High capacity
• Has moving parts
• Can be written indefinitely
• Uses defragmentation

Question 33

What is a Optical disk?

Answer 33

Optical disks – These are storage devices that use pits and lands on their surface to represent data, which is read by reflecting a laser off the disk.

Question 34

What are the pits?

Answer 34

Pits – Indentations in the disk’s aluminium layer that refract the laser light. The sensor interprets this as either a 0 or 1.

Question 35

What are the lands?

Answer 35

Lands – Flat areas on the disk where the laser light is reflected directly. The sensor reads this differently from pits, allowing for binary data representation.

Question 36

Properties of optical storage?

Answer 36

• High capacity
• Brittle

Question 37

What is the drive in solid state storage?

Answer 37

Drive: The device that reads and writes data from secondary storage.

Question 38

What is flash memory?

Answer 38

Flash memory: Uses integrated circuits in a chip comprised of billions of transistors.

Question 39

What is a transistor?

Answer 39

Transistor: A tiny electronic device capable of controlling the flow of electricity.

Question 40

What is a floating gate?

Answer 40

Floating gate: Has two oxide insulating layers which can restrict the flow of electricity, trapping electrons. The state remains even without power.

Question 41

Properties of solid state storage?

Answer 41

• Durable
• Fast speeds
• Very expensive
• Limited write cycle—high number but will eventually max out.