8888903
Description
Mind Map by Jacob Thrower, updated more than 1 year ago
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Created by Jacob Thrower
almost 7 years ago
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2.6 Data Representation
- Data Size
- Bit (b)
- The most basic unit of data in computers.
It is either 1 (on) or off (0)
- The most basic unit of data in computers.
It is either 1 (on) or off (0)
- Nibble
- Half a byte e.g. 1010
- Half a byte e.g. 1010
- Byte (B)
- 8 bits e.g. 01011100
- 8 bits e.g. 01011100
- Kilobyte (KB)
- 1024 Bytes
- 1024 Bytes
- Megabyte (MB)
- 1024 Kilobytes
- 1024 Kilobytes
- Gigabyte (GB)
- 1024 Megabytes
- 1024 Megabytes
- Terabyte (TB)
- 1024 Gigabytes
- 1024 Gigabytes
- Petabyte (PB)
- 1024 Terabytes
- 1024 Terabytes
- Bit (b)
- Data Shifting
- Left shift
- Where all the bits move to the left.
The remaining bits are filled with
0. This has the effect of multiplying
by 2.
- Where all the bits move to the left.
The remaining bits are filled with
0. This has the effect of multiplying
by 2.
- Binary shift
- A fast method of multiplying and
dividing a binary number by a power
of 2. All bits are shifted to the left or
right.
- A fast method of multiplying and
dividing a binary number by a power
of 2. All bits are shifted to the left or
right.
- Right shift
- Where all the bits move to the right. The
remaining bits are filled with 1. This has the
effect of dividing by 2.
- Where all the bits move to the right. The
remaining bits are filled with 1. This has the
effect of dividing by 2.
- Left shift
- Hexadecimal (Hex)
- A way of representing a number
using numbers from 0-9 and
A-Z. This is called Base 16
notation because there are 16
possible numbers
(0123456789ABCDE&F)
- Hex character
- A singular Hexadecimal
character. E.g D3 is made up
of the characters 'D' and '3'
- A singular Hexadecimal
character. E.g D3 is made up
of the characters 'D' and '3'
- A way of representing a number
using numbers from 0-9 and
A-Z. This is called Base 16
notation because there are 16
possible numbers
(0123456789ABCDE&F)
- Check digit
- A digit added to the end of a string of
numbers to check that data has been
received correctly
- A digit added to the end of a string of
numbers to check that data has been
received correctly
- Even parity bit
- This parity bit is added to
make a binary string have an
even number of 1s e.g.
1010001 needs another 1
added to make it even
- This parity bit is added to
make a binary string have an
even number of 1s e.g.
1010001 needs another 1
added to make it even
- Odd parity bit
- This parity bit is added to
make a binary string have
an odd number of 1s
1010001 needs a 0 added
because it already has odd
number of 1s
- This parity bit is added to
make a binary string have
an odd number of 1s
1010001 needs a 0 added
because it already has odd
number of 1s
- Check digit
- Bases
- Base 2
- A number system that
uses 2 possible numbers
(0&1)
- A number system that
uses 2 possible numbers
(0&1)
- Base 10
- A number system
that uses 10
possible numbers
(012345678&9)
- A number system
that uses 10
possible numbers
(012345678&9)
- Base 16
- A number system that uses 16 possible
numbers (0123456789ABCDE&F)
- A number system that uses 16 possible
numbers (0123456789ABCDE&F)
- Base 2
- Character
- A singular letter, number or
symbol. E.g 'A','a','7','!'
- A singular letter, number or
symbol. E.g 'A','a','7','!'
- Unicode
- Tries to cover every possible character that might be written. The most
common forms are 16-bit (65,536) and 32-bit (4,294,967,296) versions. It
covers Greek, Russian and Chinese too!
- Tries to cover every possible character that might be written. The most
common forms are 16-bit (65,536) and 32-bit (4,294,967,296) versions. It
covers Greek, Russian and Chinese too!
- Character set
- This refers to the amount
of characters that a
computer recognises.
- This refers to the amount
of characters that a
computer recognises.
- ASCII
- The most commonly used
character set in the
English speaking world.
Each character is given a 7
bit binary code (therefore
can only store 128
characters).
- The most commonly used
character set in the
English speaking world.
Each character is given a 7
bit binary code (therefore
can only store 128
characters).
- Pixel
- The squares that make up
an image. The word stands
for 'picture element'
- The squares that make up
an image. The word stands
for 'picture element'
- Metadata
- Means 'data about data'. This sounds
confusing, but you could also think of it as
'properties' (e.g Resolution, Width, Height,
Colour depth etc)
- Means 'data about data'. This sounds
confusing, but you could also think of it as
'properties' (e.g Resolution, Width, Height,
Colour depth etc)
- Colour depth
- Refers to how many bits are used
to store the colour of each pixel.
E.g 2-bit colour depth gives 4
possible colours 00,01,10,11
- Refers to how many bits are used
to store the colour of each pixel.
E.g 2-bit colour depth gives 4
possible colours 00,01,10,11
- Resolution
- Refers to the density of pixels
in an image (i.e how many
pixels are within a certain
area). It is measured in dots
per inch (dpi)
- Refers to the density of pixels
in an image (i.e how many
pixels are within a certain
area). It is measured in dots
per inch (dpi)
- Sample
- Taking a snapshot
of the wave at
regular intervals
(how many times
this happens a
second is called the
sampling rate)
- Taking a snapshot
of the wave at
regular intervals
(how many times
this happens a
second is called the
sampling rate)
- Sample size
- Refers to how many bits can be
used for each sample. 3 bits means
that 8 possible 'levels' (voltages)
can be represented. Of course, the
more levels you have, the better the
quality of the sound. The bit depth
on CD is 16 bits. On DVD is 24 bits.
- Refers to how many bits can be
used for each sample. 3 bits means
that 8 possible 'levels' (voltages)
can be represented. Of course, the
more levels you have, the better the
quality of the sound. The bit depth
on CD is 16 bits. On DVD is 24 bits.
- Bit rate
- Refers to the number of bits used per
second of audio. It's calculated using the
formula Bit rate = Sampling frequency x
Sample size
- Refers to the number of bits used per
second of audio. It's calculated using the
formula Bit rate = Sampling frequency x
Sample size
- Sampling frequency
- Refers to how many samples you
take in a second. It's usually
measured in kilohertz (kHz). A
common frequency used in MP3s
is 44.1 kHz (i.e 44,100 samples
per second)
- Refers to how many samples you
take in a second. It's usually
measured in kilohertz (kHz). A
common frequency used in MP3s
is 44.1 kHz (i.e 44,100 samples
per second)
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