Unit 2 includes:
BINARY
ASCII
TRUTH TABLES (AND, OR, NOT)
BIT
NYBBLE
BYTE
KILOBYTE
MEGABYTE
GIGABYTE
TERABYTE
CONVERSIONS:
DENARY TO BINARY AND HEX
BINARY TO DENARY AND HEX
HEX TO BINARY AND DENARY
BIT PATTERNS
SOUND
BIT RATE
IMAGE
META DATA
BINARY
ASCII
TRUTH TABLES (AND, OR, NOT)
BIT
NYBBLE
BYTE
KILOBYTE
MEGABYTE
GIGABYTE
TERABYTE
CONVERSIONS:
DENARY TO BINARY AND HEX
BINARY TO DENARY AND HEX
HEX TO BINARY AND DENARY
BIT PATTERNS
SOUND
BIT RATE
IMAGE
META DATA
Binary
The CPU only has two states, either ON or OFF, so need a numbering system with only 2 values
We use 1 and 0
1=ON and 0=OFF
ASCII
American Standard Code for Information Interchange
255 symbols can be recorded and represented
There are 128 standard ASCII codes, each of which can be represented by a 7 digit binary number from 000000 through to 111111 e.g;
A= 00000001
B=00000010
C=00000011
D=00000100
E=00000101
F=00000110
G=00000111 etc.
The CPU only has two states, either ON or OFF, so need a numbering system with only 2 values
We use 1 and 0
1=ON and 0=OFF
ASCII
American Standard Code for Information Interchange
255 symbols can be recorded and represented
There are 128 standard ASCII codes, each of which can be represented by a 7 digit binary number from 000000 through to 111111 e.g;
A= 00000001
B=00000010
C=00000011
D=00000100
E=00000101
F=00000110
G=00000111 etc.
Truth Table
The output is true if either A or B are true
Data Storage Units
Bit=1 or 0
Nybble=4 bits (e.g. 0011)
Byte=8 bits (e.g. 00001111)
Kilobyte=1024 bytes
Megabyte= 1024 kilobytes
Gigabyte= 1024 megabytes
Terabyte= 1024 gigabytes
Bit=1 or 0
Nybble=4 bits (e.g. 0011)
Byte=8 bits (e.g. 00001111)
Kilobyte=1024 bytes
Megabyte= 1024 kilobytes
Gigabyte= 1024 megabytes
Terabyte= 1024 gigabytes
Conversions- see next page for all conversions
Bit Patterns
all the instructions the computer reads and understands
on 1 /off 0 pixels -machine code
A combination of binary digits arranged in a sequence
1=2
2=4
3=8
4=16
|
\/
8=128
9=256
How does a computer know if it is reading instructions or data
Sound
Sampling- the process of converting sound into binary numbers
Sound waves converted into bars (on a graph)
more bars on the graph=increased sample rate which means better quality
sample(number of the bars) is stored
converted into binary (height and intervals) for the computer to code
all the instructions the computer reads and understands
on 1 /off 0 pixels -machine code
A combination of binary digits arranged in a sequence
1=2
2=4
3=8
4=16
|
\/
8=128
9=256
How does a computer know if it is reading instructions or data
Sound
Sampling- the process of converting sound into binary numbers
Sound waves converted into bars (on a graph)
more bars on the graph=increased sample rate which means better quality
sample(number of the bars) is stored
converted into binary (height and intervals) for the computer to code
Bit Rate
The number of bits that are conveyed or processed per unit of time.
It measures how much data is transmitted in a given amount of time (commonly bps-bits per second)
Images
A 'real' image is an analogue picture that we see where the colours and tones blend together smoothly.
bitmap image -hundreds of thousands of rectangles all containing a number of colours
pixel- the amount of bits in each rectangle
any colour can be split into any combination of red, blue or green, each colour has 1 byte, each byte have 256 levels so 256 different shades of red, blue or green
with a 3 byte system there are 256x256x256 =16.8 million possible colours therefore higher resolution
colour depth=the number of bits used to represent a colour (therefore the more depth, the wider the colour range)
The number of bits that are conveyed or processed per unit of time.
It measures how much data is transmitted in a given amount of time (commonly bps-bits per second)
Images
A 'real' image is an analogue picture that we see where the colours and tones blend together smoothly.
bitmap image -hundreds of thousands of rectangles all containing a number of colours
pixel- the amount of bits in each rectangle
any colour can be split into any combination of red, blue or green, each colour has 1 byte, each byte have 256 levels so 256 different shades of red, blue or green
with a 3 byte system there are 256x256x256 =16.8 million possible colours therefore higher resolution
colour depth=the number of bits used to represent a colour (therefore the more depth, the wider the colour range)
Metadata
extra data information added onto data (e.g. hashtags)
a fancy term for 'data about data' it describes the structure of the data file, usually located at the start of the file
it looks at the file type, how many horizontal pixels there are, how many vertical pixels and the colour depth of the file
Metadata for images:
identify who owns it
copyright and contact information
what camera created the file
exposure information
descriptive information (e.g. keywords about the photo, making the file searchable on the computer and/or the Internet)
Some metadata is written by the camera and some is input by the photographer and/or software after downloading to a computer. Most digital cameras write metadata, and some enable you to edit it.
extra data information added onto data (e.g. hashtags)
a fancy term for 'data about data' it describes the structure of the data file, usually located at the start of the file
it looks at the file type, how many horizontal pixels there are, how many vertical pixels and the colour depth of the file
Metadata for images:
identify who owns it
copyright and contact information
what camera created the file
exposure information
descriptive information (e.g. keywords about the photo, making the file searchable on the computer and/or the Internet)
Some metadata is written by the camera and some is input by the photographer and/or software after downloading to a computer. Most digital cameras write metadata, and some enable you to edit it.