Unit 8.1 Data Representation Flashcards
What is the highest number you can represent with 1 byte?
255
How many bits are in one byte?
8
What is the highest two’s complement number you can represent with 8 bits?
127
What is the method for converting a binary number directly into Hexadecimal?
Split the 8 bits into two 4 bit nibbles.
Convert each nibble into a Denary number.
If either number is 10 - 15, convert to relevant letter.
Join the two conversions together.
What are the range of characters for the Hexadecimal system?
0 - 9, A - F
What base is the hexadecimal system?
16
What does ASCII stand for?
American Standard Coding for Information Interchange
What is the purpose of the ASCII system?
Standardised system for communicating text across the internet.
What are the limitations of the ASCII system?
Cannot be used for all languages as it cannot represent all possible characters. For example, letters with accents.
What is the smallest element of an image?
Pixel
What is the colour depth of an image?
The number of colours available to each pixel.
A 4 bit colour depth has how many colours?
16
When converting to digital sound, the sample rate is the…?
The number of samples you take in one second.
When converting to digital sound, the sample interval is the…?
Gaps between each of the samples.
What are the effects of reducing the sample rate and sample interval?
Smaller size file but poorer quality sound.
Convert FF from Hexadecimal to Denary.
255
How many places are there between uppercase and lowercase letters?
32
Convert 1001 1001 into Denary.
153
