4.2 Hardware

Question 1

What is the CPU?

Answer 1

It is a central procession unit and controls the manipulation of data. It uses data to perform operations. It includes:

1. ALU
2. CU
3. Registers

Question 2

What are CPU cores?

Answer 2

A core is a set of CU, ALU, and registers. Some CPUs have multiple cores, which means they can process instructions much more quickly.

Question 3

What is done by the MDR?

Answer 3

It stores the current data needed to carry out instructions.

Question 4

What is the ALU?

Answer 4

It is the arithmetic logic unit, where mathematical and logical calculations are done.

Question 5

What is the CU?

Answer 5

It is the Control Unit, which controls the activities done by the CPU

Question 6

What are Registers?

Answer 6

They are quick, small stores of data within the CPU.

Question 7

What is the Von Neumann Architecture?

Answer 7

It contains three major characteristics:

1. The Main Memory
   
   1. Stores Binary Values
2. The CPU
3. Inputs and Outputs

Question 8

What is the Fetch-Decode-Execute Cycle?

Answer 8

Fetch:

1. The Address of the next instruction is copied from the PC into the MAR
2. The PC is incremented by 1

Decode:

1. The CU obtains the address of the current instruction from the MAR via the RAM
2. The RAM returns the data to the MDR via the data bus

Execute:

1. The data from the MDR is copied into the CIR and decoded by the ALU which results are stored in the ACC

Question 9

What are the 5 Registers?

Answer 9

1. Memory Data Register
2. Memory Address Register
3. Program Counter
4. Current Instruction Register
5. Accumulator

Question 10

What is done by the MAR?

Answer 10

The MAR stores the address of the current data that the processor requires.

Question 11

What affects a CPU’s Speed?

Answer 11

1. The number of cores
2. The Cache Size
3. The Clock Speed

Question 12

What is done by the PC?

Answer 12

The Program Counter stores the address of the next instruction, and it increments once the address is copied into the MAR.

Question 13

What is done by the AC?

Answer 13

The accumulator stores mathematical and logic results being transferred from or to the memory unit.

Question 14

What is done by the CIR?

Answer 14

The Current Instruction Register contains the current instruction which is being carried out.

Question 15

Why do computers need a clock?

Answer 15

The clock provides timing signals to synchronize the circuits. CPUs are designed to operate at their respective clock speeds, the faster the clock speed the faster the CPU.

The faster the clock speed, the faster the fetch-execute-decode cycle.

Question 16

What is Clock Speed?

Answer 16

The Clock Speed refers to the amount of electrical pulses that the clock inside the CPU can produce every second.

Question 17

What is the Main Memory (Primary Storage)?

Answer 17

It is what is directly accessible by the CPU and includes RAM, ROM, and Cache.

Question 18

What in included in the Main Memory?

Answer 18

It is memory directly accessible by the CPU, which includes RAM, ROM, and Cache - although predominantly it refers to the RAM.

Question 19

What are the two kinds of memory?

Answer 19

Volatile and Non-Volatile. Volatile Memory is temporary and lost when power is, whilst Non-Volatile memory retains data when power is lost.

Memory is normally Volatile, besides ROM. Storage is Non-Volatile

Question 20

What is the RAM?

Answer 20

Random Access Memory is RAM. Ram has quick read/write times. It loads open programs and operating system data currently in use. Essentially it stores the data of what is currently being used.

Question 21

What is ROM?

Answer 21

Read-only memory is Non-Volatile, and can only be read and cannot be changed. It contains essential programs, like the programs used to boot the computer.

Question 22

What is Cache Memory?

Answer 22

It is Volatile, and stores copies of frequently used data. CPU Cache sits between the CPU and RAM and is checked before RAM in the fetch phase. Because it stores commonly used data, it is placed much closer to the CPU, although browsers and storage may also have caches.

Question 23

What is Virtual Memory?

Answer 23

It is a temporary memory, it is a memory management procedure used when the RAM is full. It is created from secondary storage that is temporarily converted into volatile memory. Data from non-current processes are sent as pages from the RAM to the Virtual Memory, and it is much slower.

Question 24

What is Flash Memory?

Answer 24

It is Non-Volatile, a part of SSD (Solid-State Memory; non-mechanical). It is more reliable and durable, but can only be overwritten a finite amount of times.

Question 25

What are the Buses(Connections)?

Answer 25

Buses carry data around the computer, the names are representative of the data they carry. They are a collection of wires through which data is transmitted, and they are:

1. Data Bus
2. Address Bus
3. Control Bus (Instructions)

Question 26

Which directions can the buses go?

Answer 26

CPU → Address Bus → RAM (UniDirectional)

CPU ←→ Data Bus ←→ RAM (Bidirectional)

CPU ←→ Control Bus ←→ RAM (Bidirectional)

Question 27

What is the Secondary Storage?

Answer 27

It is storage not directly connected to the CPU and is Non-Volatile.

Question 28

What are the keywords for Secondary Storage?

Answer 28

1. Portability
2. Durability
3. Reliability
4. Cost
5. Capacity
6. Speed

Question 29

What is Optical Storage?

Answer 29

It is storage stored through pits and lands. Data is written via laser to burn pits through the disks, light is then shone on the disks in which the reflection of light is used to read data.

It includes:

1. CD
2. DVD
3. Blu-Ray

Question 30

What are the advantages and disadvantages of Optical Storage?

Answer 30

Advantages:

1. Good Portability
2. Can be Rewritten

Disadvantages:

1. Small Capacity
2. Easily Damaged

Question 31

What is Magnetic Storage?

Answer 31

Magnetic Storage uses read/write heads that contain electromagnets. Parts of the disc are magnetized (1) or demagnetized (0) - and the heads read this.

Question 32

What is Solid-State Storage?

Answer 32

It is a form of flash memory, so it is non-mechanical. Electrons are stored in transistors and capacitors, in which data is stored. When it is connected to power, these electrons ‘flash’ into the device.

Question 33

What are the Advantages and Disadvantages of Magnetic Storage?

Answer 33

Advantages:

1. Cheaper
2. Larger Storage

Disadvantages:

1. Easily Broken
2. Noisy and generates heat

Question 34

What are the Advantages and Disadvantages of Solid-State Storage?

Answer 34

Advantages:

1. Much Faster
2. Reliable because non-mechanical
3. silent
4. portable
5. don’t produce heat

Disadvantages:

1. Expensive
2. Degrades over multiple read-write cycles

Question 35

What is Cloud Storage?

Answer 35

Cloud Storage is data stored on multiple servers, in remote locations. Servers use magnetic/solid-state storage. It operates through a web-based API.

Question 36

What are the Advantages and Disadvantages of Cloud Storage?

Answer 36

Advantages:

1. Easily Accessible anywhere with an internet connection
2. Can share files with other people easily

Disadvantages:

1. If no internet, no access
2. Must trust Provider
3. Can be expensive

Question 37

What are Embedded Systems?

Answer 37

They are special-purpose computers that perform very specific tasks and aren’t easily programmed. They include:

1. Dishwashers
2. Heating Systems
3. Microwaves
4. Calculators