Yr10 February Mock - QFocus
Page 1: CPU Performance and Components
Cache Size and CPU Performance
The cache size significantly impacts CPU performance. A larger cache allows data to be transferred faster to the CPU, enhancing its efficiency.
Data retrieval from the cache is quicker than from RAM, reducing latency in processing tasks.
Identifying Computer Components
Key components of a computer can be defined as follows:
MAR (Memory Address Register): Stores a single memory address.
MDR (Memory Data Register): Stores frequently used instructions and data.
Cache: Holds data that is frequently accessed for faster processing.
Program Counter: Keeps track of the instructions being executed.
RAM (Random Access Memory): Contains all currently running data and instructions.
Registers in CPU
An example of a register not listed in the earlier table is the accumulator. This register is used to store the results of arithmetic and logic operations temporarily.
Audio File Conversion Process
When converting music (e.g., an audio file of guitar playing) into a digital format, the height of sound waves gets sampled. This measurement occurs at regular intervals, turning the analog signal into a digital one represented by binary code.
Page 2: Memory, Storage, and Compression
Character Set
A character set refers to all the different characters that a computer can represent.
ASCII Representation
ASCII (American Standard Code for Information Interchange) can represent 256 different characters. This encoding system allows computers and devices to communicate text in a standard format.
Estimating File Size
To estimate the file size of a text file with 2000 characters:
Calculate bits: 2000 characters * 8 bits/character = 16000 bits
Convert to bytes: 16000 bits / 8 = 2000 bytes
Convert to kilobytes: 2000 bytes / 1000 = 2 kilobytes.
Compression Methods
For reducing the file size of images and videos, compression methods that significantly reduce size while maintaining quality include:
Decreasing the overall file size, which also results in faster uploads to, and downloads from, servers.
Functions of a Router
Key tasks performed by a router include:
Receiving, forwarding, transmitting packets of data across networks.
Maintaining routing tables that determine the best paths for data.
Identifying and selecting the most efficient paths to various destinations.
Assigning unique IP addresses to devices on a network.
Converting packets from one network protocol to another.
Page 3: Protocols and Addressing
Layered Protocols
Protocols utilize layers for various reasons:
Each layer operates independently, allowing for individual changes without affecting others.
Layers can be tailored for specific tasks, facilitating specialized development.
Standards can be established for each layer, ensuring compatibility.
IP Address Examples
A valid IPv4 address follows the format of four groups of denary numbers (0-255) separated by dots.
Example: 123.16.46.72
A valid IPv6 address is composed of eight groups of hex numbers separated by colons, which can include a double colon that replaces consecutive zero groups.
Example: 0252:5985:89ab:cdde:a57f:89ad:efcd:00fe
Format of a MAC Address
A MAC (Media Access Control) address is typically formatted in hexadecimal, consisting of:
6 groups of two-digit hexadecimal numbers (totaling 12 hex numbers).
A length of 48 bits.
The first half identifies the manufacturer, while the second half signifies the device's unique serial number.
Page 4: Importance of Encryption
Need for Encryption
Libraries transmitting data without encryption face potential risks. Reasons for implementing encryption include:
Protecting the integrity and confidentiality of intercepted data, making it unrecognizable if compromised.
Ensuring that only authorized personnel access sensitive or personal information is crucial for compliance with legislation like the Data Protection Act (DPA).
Revision Status Tracker
The topics under review include Systems Architecture, focusing on CPU and memory/storage concepts, as well as Computer Networks, which covers hardware and addressing protocols.