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Computer Science - Coggle Diagram
Computer Science
Data Storage Numbers
Data Storage-Numbers:
Denary can be converted to binary by writing all the binary numbers and think about the number of 1,2,4,8,16 etc that fits in the number. To convert back, add up all off the binary numbers.
To convert to hexadecimal, take the denary number and divide by 16. That number will be either 1,2,3,4,5,6,7,8,9,A,B,C,D,F etc. Then take the remainder of the number you divided and put it in the second thing .
Data Storage Images
Each pixel has a colour and each pixel is stored in binary
Metadata: Data about an image
Higher colour depth and resolution will increase the file size but the quality will increase
Data Storage Sounds
Sound can be sampled with bit rate a certain amount of times a second. It will then convert that to digital sound and we can hear it
Duration will increase a file size and so will bit depth and sample rate. Sample rate and bit depth will make it a higher file size
Compression
Compression reduces file size and makes data load up faster
Lossy: Data that is unnecessary is removed. Data is permanently lost
Lossless: Data that is similar is grouped together and reconstructed. No data is lost
Memory and Storage
Main Memory:
RAM ( Random Access Memory) used to store data that is being used by the computer system for faster access.
Secondary Storage:
Non volatile, stays after the computer system turns off.
Magnetic: Cheap, Reliable, not durable and not portable
Solid State: Expensive, Fast, Reliable, Durable, Portable depending on what you buy
Optical: Cheap, Can only be written on once, not durable, not portable
Cache stores frequently accessed data
Units
Storage Units:
Bit (one bit)
Nibble (4 bits)
Byte (8bits)
Kilobyte (1000 bytes)
Megabyte (1000 kb)
Gigabyte (1000mb)
Terabyte (1000gb)
Petabyte (1000tb)
Data needs to be converted into a binary format to be processed by a computer
Data needs to be in a binary format because its the only language the computer understands because the computer is made up of switches that can only be On/Off
Networks and Topologies
A Local Area Network is one that has two or more network-enabled devices connected within a fairly close geographical area.
A wide area network (WAN) connects two or more local area networks (LAN) that are in different geographical locations.
System Architecture
Different Parts of the CPU:
Cache
Registers
Control Unit
Registers:
Program Counter
Memory Address Register (MAR)
Memory data registers (MDR)
