Chapter 1 Flashcards
Why do we use hexadecimal?
Shorter way of representing binary so it takes up less storage space. Easier for programmers to debug, read, write, understand and find errors in code.
What is a MAC address and what base is it written in?
A unique address given to a device at the manufacturing stage that can be used to identify it later on. Written in hexadecimal.
How do computers represent text in binary?
Using a character set. A character set contains all the characters in that character set and the binary value assigned to each character. ASCII is an 8 bit character set that can represent up to 256 characters. Unicode is a 16 bit character set that can represent approximately 65000 characters.
How do computers represent images in binary?
An image is made up of tiny dots called pixels. Each pixel has a color depth (number of bits used to create each color in an image) and a corresponding binary value. If the computer is given metadata such as the resolution and dimensions, it can create the image.
How is sound represented in binary?
Sound is made up of sound waves. A sound sample is a little piece of sound recorded at regular time intervals, they make up the sound waves. They’re converted into binary values. The higher the sample rate (number of samples recorded per second), the higher the accuracy. Further date is required, this is the sample resolution. This is the number of bits used to record a sound sample, usually 16 bits.
How to calculate the size of a file?
Number of images x color depth x image resolution
How to calculate the length of the soundtrack?
Length of soundtrack x sample resolution x sample rate
State the difference between lossy and lossless compression.
Lossless compression is an algorithm that reduces the size of a file by temporarily alternating the data, lossy compression reduces the size of a file by permanently removing data.
Perceptual music shaping:
A lossy compression method that removes sounds not usually heard by humans.
Run length encoding:
An algorithm that groups together and indexes repeating patterns.
What is a proxy server?
A server that acts as an intermediary between a user’s computer and the internet.
How does a proxy server improve security?
Hides the users IP address. Blocks access to harmful websites.
What is caching in a proxy server?
Storing copies of frequently used web pages to load them faster for users.
Characteristics of an embedded system:
Has a microprocessor, performs a specific task. It is a computer built into a larger device dedicated to specific task.
