Exam essentials

Give 3 examples of data stored in RAM

• Operating system data currently in use

• Applications and software currently running

• Data currently being processed

What’s the definition of a pixel

The smallest unit of a digital image or display, representing a single point of color.

What’s resolution

The number of pixels in each dimension (width and height) that a display or image contains.

How do you calculate file sizes of images?

Resolution x colour depth

What is solid state storage

Solid-state storage is a type of storage that uses flash memory to store data. It has no moving parts, making it faster and more durable than traditional magnetic storage.

Name two features of magnetic storage

• Uses magnetic fields to store data on rotating disks (platters)

• Typically has larger storage capacity at a lower cost compared to solid-state drives

Why is file compression needed?

• To reduce file size for faster upload/download times

• To save storage space

• To reduce bandwidth usage during transmission

What is packet switching

Packet switching is a method of data transmission where data is broken into small packets. Each packet is sent independently over the network and reassembled at the destination

What are the parts of a packet

1. The header, it contains the Source address, Destination address, Sequence number and Error-checking information

2. Payload (data)

3. Trailer, it contains data that lets the node know when the packets are all sent

What is serial data transmission?

Serial data transmission is the transmission of data bit by bit on one channel

What is parallel data transmission

Multiple bits are transmitted simultaneously over multiple channels.

What is full duplex data transmission

Full-duplex data transmission allows data to be sent and received simultaneously in both directions.

How do you do a parity bit check?

Add a parity bit to ensure the total number of 1s and 0s in the byte is even.

How can a parity block check find an error that a parity byte check can't?

A parity block check uses a matrix of bits, checking both rows and columns. This can detect errors that a simple parity byte check might miss by identifying inconsistencies in both dimensions.

What component sends signals to the CPU

the control unit

What does the MDR (memory data register) do?

The MDR holds the data that is being transferred to or from the memory.

What is meant by 2.4Ghz clock speed?

2.4 GHz clock speed means the CPU can execute 2.4 billion cycles per second.

Name the registers in the CPU

• Program Counter (PC)

• Memory Address Register (MAR)

• Memory Data Register (MDR)

• Accumulator (ACC)

• Instruction Register (IR)

How is analogue sound Recorded and converted to digital?

Analogue sound is sampled at regular intervals and each sample is converted to a binary number representing the amplitude of the sound wave at that point.

Why might a musician chose lossless data transmission

Lossless compression preserves all the original audio data, ensuring no quality is lost, which is important for high-fidelity recordings.

What is the difference between ASCII and Unicode?

• ASCII uses 7 or 8 bits to represent characters, allowing for 128 or 256 unique characters.

• Unicode uses up to 32 bits, allowing for over a million unique characters, and supports a wider range of characters from different languages and symbols.