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computing revision part 1 - Coggle Diagram
computing revision part 1
different data measures
nibble
4 bits
byte
8 bits
bit
1 or 0
kila byte
1000 bytes
mega byte
1000,000 bytes
binary place value
128 64 32 16 8 4 2 1
denary ---> binary
eg. 12---->
128 64 32 16 8 4 2 1
0 0 0 0 1 1 0 0
whats 47 in binary?
binary----> denary
eg. 10--->
128 64 32 16 8 4 2 1
0 0 0 0 1 0 1 0
what is 17 in binary?
charecter representation eg. "A" , "?" , "#"
ASCII
7 bit character set
only 128 combinations
extended ASCII
8 bit character set
256 combinations
can now store foreign language symbols + more punctuation
UNICODE
16 bit character set
enough for every dead and living language inc. emojies
TRADE OFF
fewer characters<------------> more characters smaller file sizes<------------>large file size
example: h e l l o saved in ascii 7 bits.... 7 x 5 = 35 bits
h e l l o saved in unicode 16 bits.... 16 x 5 = 80bits
sounds
AND- anolouge to digital
MICROPHONE
DAC- digital to anolouge
SPEAKER
V
SOUND CARD
<-
->
BINARY
V
sound sample
good but not exact representation of the sound
better if increase the sample rate
increase the bit rate
tradeoff
low quality<------------> high quality smaller file sizes<------------>large file size
sound file size = bitrate x sample frequency x length of sound x no. of channels
pictures
vector images : binary instructions to redraw the image
bit map images : binary contains colour info for each pixel
picture file size = width x height x colour depth