1. Hardware

Question 1

What is Von Neumann?

Answer 1

• The VN architecture used the idea of storing programs instructions and data in main memory and moving them between memory and the processor.
• The processor can access the instructions and data in the main memory as required to execute the program. by using buses.
• This means the same address and data buses are used to transfer instructions and data.

Question 2

What is Harvard Architecture?

Answer 2

Harvard architecture keeps instructions and data in separate memories which the processor accesses using separate data and address buses.

Harvard is used extensively in embedded systems.

Question 3

How does multiple cores affect performance?

Answer 3

The more cores a computer has, the more instructions it can execute at the same time so the computer will perform more efficiently.

Question 4

What is parallel processing?

Answer 4

Dividing a computation into subtasks that can be processed in parallel (one task per core at the same). This is known as parallel processing and it is only possible on multicore systems

Communication and synchronisation between the different subtask are typically some of the greatest obstacles to getting efficient parallel program performance

Question 5

How does a larger cache affect system performance?

Answer 5

The larger the cache, the more instructions can be queued and carried out. Storing instructions in cache reduces the amount of time it takes to access that instruction and pass it to a CPU core.

Question 6

How does clock speed affect performance?

Answer 6

The greater the clock speed, the faster the instructions. Making a processor perform more instructions per second than it is recommended to (overclocking), could cause the processor to overheat.

Question 7

Describe The FDE Cycle

Answer 7

1.The program counter (PC) keeps the address of the next instruction to be executed. The contents of the PC are copied to the memory address register (MAR), which is connected to the address bus. The address of the next instruction to be executed is placed on the address bus.

2.Once the address of the instruction is on the address bus, the control unit instructs a memory read operation to allow the contents of the memory location to be transferred to the processor. The instruction that is stored at that address is transferred from the main memory to the processor (using data bus) , and is saved in the memory data register (MDR). The PC is incremented by 1.

3.The contents of the memory data register (MDR) are copied to the current instruction register (CIR).

4.The control unit decodes the instruction that is kept in the current instruction register (CIR) and the instruction is executed. Depending on the type of instruction, executing an instruction can involve the ALU and the general-purpose registers, the accumulator, or the main memory.

Question 8

What is the purpose of secondary storage?

Answer 8

• Secondary storage provides permanent storage for data files and applications.
• Secondary storage is non-volatile (so data is not lost when power is removed).
• Secondary storage needs to be high capacity and low cost. It needs to be fast enough for loading and saving files, and it needs to provide reliable permanent storage so that files are not lost or easily corrupted.

Question 9

What is a network?

Answer 9

A network is a group of devices connected together, wirelessly or using cables, so they can communicate with each other and share resources.

Question 10

What is the importance of networking standards?

Answer 10

Network standard allows communication between different network devices so its impossible to create networks that communicate without them.

• Easier to develop – can be done one layer at a time
• Allows different companies to work together / international standardisation
• Leads to more competitive pricing

Question 11

What’s HTTP(S)?

Answer 11

Hypertext Transfer Protocol is used to make a request for a webpage. HTTPS uses protocol (TSS/TLC) to encrypt the data making it more secure.

Question 12

What is FTP?

Answer 12

File Transfer Protocol is used for the transfer of computer files from a server to a client on a computer network. It’s used for sharing files with other users, either for storage or collaboration.

Question 13

What is SMTP and IMAP?

Answer 13

Simple Mail Transfer Protocol transfers the email from the client device to the linked mail server.

Internet Message Access Protocol is used to synchronise a client email account with an account on the mail server. The server returns new emails and deletes any emails that were deleted locally on the client application.

Question 14

What is TCP and UDP?

Answer 14

TCP is more reliable and makes sure every data packet arrives by using an error checking feature.

UDP is faster but less reliable so if any packets arrive out of sequence or are missing, they are ignored.

TCP - video streaming services
UDP - video games

Question 15

What is Handshaking?

Answer 15

Handshaking is the process that establishes communication between two networking devices.

Question 16

What is the internet?

Answer 16

The internet is a global network of interconnected networks that communicate using a common set of standards and protocols.

Question 17

What are the functional characteristics of a HDD?

Answer 17

• The drive is a mechanical device with many moving parts.
• Hard drives have a fast transfer rate and a fairly fast access time.
• Hard drives are a magnetic medium and store data on a hard drive platter.
• Hard drives consist of an actuator arm which attaches to a RW head which moves across the disc reading/writing data.
• The faster the platter spins, the faster the data can be read from the disk. A common speed for a hard drive can be 7200 RPM but it can vary.

-Fragmentation occurs when there is insufficient contiguous space to store the file. Each part of the file will be in a separate location which has to located, taking longer to access the file.

• Good capacity and cost

Question 18

What is SSD?

Answer 18

• An SSD is an electronic device that uses flash memory, and has no moving parts.
• Greatest access speed
• The absence of moving parts means that mechanical failure is far less likely. The lack of moving parts also reduces the amount of energy consumed, which, in turn, reduces the amount of heat generated in a computer system.
• Limited lifespan. The number of times that an SSD can be written to is finite, and memory cell ‘leakage’ can be a problem if devices are not powered up
• more expensive (per GB) compared to HDD

-SSDs are particularly suitable for storing files that are read or changed frequently.

Question 19

Name and describe the function of main components in the CPU

Answer 19

CU - Directs the flow of data
- Coordinates the other parts of the CPU
- Generates clock ticks

ALU - Carries out simple calculations and logical operations

Registers - small/fast access/ temporary storage used to store frequently used data and instructions .typically addressed by mechanisms other than main memory

buses - connects all the internal components of a computer such as CPU and memory to the motherboard.

Question 20

What is DHCP

Answer 20

Assigns dynamic IP addresses to devices on a network. This is important as the protocol/p returns unused addresses to the pool of available IP address for reallocations

Question 21

What is caching?

Answer 21

Used to store frequently used data from memory.
- Faster than Ram but volatile
- Similar to Ram but resides closer to the CPU
- used by processor to avoid having to slow down to the speed of RAM
- different level of cache which denote speed and characteristics

Question 22

What is UDP

Answer 22

Universal Datagram Protocol is responsible for sending datagrams across a network with very few error recovery services.

Question 23

Optical Drive

Answer 23

Optical drives work by using lasers to store data

Burning microscopic indentations, in a spiral pattern, into a disc such as CD

Indentations and their absence creates pits and lands

When the laser shines on the disc’s surface, lands reflect the light back, whereas pits scatter the laser beam. A sensor looks for the reflected light. Reflected light (lands) represents a binary ‘1’, and no reflection (pits) represents a binary ‘0’.

On bluray, pits and lands are closer together, meaning that the laser’s wavelength is shorter (blue)

DVD-ROM uses the same techniques to store data, but the data is stored on two layers.

• Portbale
• Can buy in large batches
• More durable
• longevity - fairly robust, susceptible to scratching if not well protected

Question 24

What is a protocol?

Answer 24

A protocol is an agreed upon format which allows two devices to communicate

Question 25

What is TCP/IP?

Answer 25

Allows any networked computers to communicate with each other. This is important as TCP/IP specifies how signals are routed and transported around a network.

Question 26

What is Application Layer

Answer 26

The layer where user-interface applications operate, involving protocols that user applications interact with like HTTP,FTP etc.

Question 27

Transport Layer

Answer 27

Responsible for end-to-end communication over the network, managing data flow , error checking and segmentation.

Includes protocols such as TCP and UDP.

Question 28

Network Layer

Answer 28

Provides the functionality required to transmit data between two different networks including addressing and routiung

Includes protocols such as IP which creates data packets and allows to be delivered

Question 29

Data Link Layer

Answer 29

Manages data transfer between computers on the same network and handles error detection and correction.

Contains Wi-Fi and ethernet protocols

Question 30

Physical Layer

Answer 30

Responsible for transmitting raw bits over a physical medium such as cable, fibre optics or wireless

Question 31

IP packet

Answer 31

Version - IPv4 or IPv6

Time to live - lifespan of the packet to prevent it from circulating indefinitely

IHL - show how many 32-bit words are present in the header

Identification - used to identify fragments of an IP datagram quickly

Protocol - TCP/UDP

Source Address - The IP address of the sender

Destination Address - The IP address of the destination

Data variable - The data