Computer Science - Representing data

?
  • Created by: becky.65
  • Created on: 20-05-15 11:59
How are all the symbols on a computer displayed?
By a code
1 of 33
What are the codes stored in?
Binary
2 of 33
What is the character set for the computer?
The list of codes and matching characters
3 of 33
How many bits does ASCII use?
7 bits or extended ASCII uses 8 bits
4 of 33
How many bits does Unicode use?
16 or 32 bits
5 of 33
What does Unicode provide
A character set for a computer that includes a wide range of specialist symbols
6 of 33
Since Unicode keeps the same assignment of codes for the original ASCII codes so what could ASCII be considered as now?
A subset of Unicode
7 of 33
How are images stored on a computer
In binary
8 of 33
How is the computer able to work out how to turn binary values into the image?
The file with the binary data contains metadata
9 of 33
What is a pixel?
One 'dot' in the image
10 of 33
What does the number of bits we use for a pixel determine?
How many colours each dot can represent
11 of 33
What two things need to get greater for more bits needed to store the data
The more bits per pixel and the greater the colour depth
12 of 33
What is 16bpp called?
High colour
13 of 33
What is 24bpp called?
True colour
14 of 33
What is the resolution?
The number of pixels per unit
15 of 33
What is a bitmapped image?
An image built up from pixels
16 of 33
What happens when a bitmapped image is displayed enlarged on a screen?
The actual image size does not change, the dots just get bigger and the image becomes pixelated
17 of 33
Why are sound files described by metadata?
To make sure the computer can interpret the data accurately
18 of 33
What does the data stored include?
The audio codec and the sample rate
19 of 33
What form is sound in?
Analogue form
20 of 33
Since it is in analogue form, what needs to happen for sound to be transferred to a computer?
It needs to be digitally sampled
21 of 33
What is the sample interval?
Often used to describe the sample rate and is the time between samples being taken
22 of 33
So the higher the sample interval the...?
Lower the sample rate
23 of 33
What happens when sound is sampled at a low rate?
Very few samples are taken, there is a poor match between the original sound and the sampled sound and a small file size is required
24 of 33
What happens when sound is sampled at a higher rate?
Many more samples are taken, there is a good match between the original sound and the sampled sound and a large file size is required
25 of 33
What is the bit rate?
The amount of space to to store each second of the sample
26 of 33
What does a higher bit rate mean?
More accurate sampling at each point which gives better quality and more data needs to be stored which needs a larger file size
27 of 33
What does the CPU when it fetches an instruction?
It decodes it in order to find out what to do next
28 of 33
What are the two parts of the instruction
Operator, which is the instruction part ad the operand which is the data part
29 of 33
What does the operator binary code represent?
An operation, for example ADD
30 of 33
What does the operand represent?
The data that the operator uses
31 of 33
What is the accumulator?
A special register in the CPU used to store the results of any calculation
32 of 33
How does a computer tell the difference between data and instructions?
It cannot tell the difference between them and simply deals with what it finds according to what us expects to find
33 of 33

Other cards in this set

Card 2

Front

What are the codes stored in?

Back

Binary

Card 3

Front

What is the character set for the computer?

Back

Preview of the front of card 3

Card 4

Front

How many bits does ASCII use?

Back

Preview of the front of card 4

Card 5

Front

How many bits does Unicode use?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Computing resources:

See all Computing resources »See all Representing data resources »