Fundamentals of Data Representation Flashcards
What are the 3 number bases?
Denary (base 10)
Binary (base 2)
Hexadecimal (base 16)
Why is hexadecimal often used?
Large numbers can be represented using fewer digits, therefore it is easier to understand
What are the rules for binary addition?
0 + 0 = 0
1 + 0 = 1
0 + 1 = 1
1 + 1 = 0 c 1
1 + 1 + 1 = 1 c 1
What are the rules of binary shift?
Shift left - multiplication
Shift right - division
Why does hex not save memory?
It must be converted to binary before the computer can understand it
What would a hex table look like?
16^1 16^0
How many bits does ASCII use?
7 bits
How many bits does extended ASCII use?
8 bits
How many possible ASCII characters are there?
128 = 2^7
Maximum bring 127 (0 inclusive)
How many bits does Unicode use?
16 bits
= 2^16 possible combinations
What are the limitations of ASCII?
No foreign languages
No special characters/ symbols (emojis)
Why must all data be converted to binary for a computer to be able to process it?
Computers work in binary
What is a digital bitmapped image?
An image made of pixels, where each pixel represents a binary number
What is the colour depth of an image?
The amount of bits available for colours in an image
How does colour depth affect file size?
The bigger the colour depth, the more bits are needed to represent a pixel, therefore the greater the file size
