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Computer Science - Coggle Diagram
Computer Science
System Architecture (1.1)
Regesters
MDR
PC
MAR
accumulator
CPU
Parts of the CPU
ALU
Cashe
CU
Memory and storage (1.2)
Main memory
RAM
we need RAM in order to store the data of the applications that are in use, this allows for the CPU to process data faster as it can receive the data faster as RAM is closer and is smaller than Primary storage which is larger which will take longer to search through for the data the CPU needs
ROM
we need ROM to store the BIOS even after the computer has been turned off, this makes ROM non-volatile - this means that ROM will keep the data saved on it even after it is powered off. ROM is also read only, this means that data cannot be written to it.
VM
virtual memory (VM) is used when RAM is full in order to keep the computer running. This is done by moving programs not in use to main memory and moving the program currently in use to RAM, this will allow new programs to be put into RAM.
Secondary storage
Types of secondary storage
Magnetic
examples
Hard disk drives
floppy discs
video tapes
advantages
cheap per GB
disadvantage
not durable
optical
examples
optical disks
advantages
cheap
portable
disadvantages
not durable
low capacity
low numbers of write cycles
solid state
examples
flash drives
Solid state drives
disadvantages
expensive per GB
limited read / write cycles
advantages
quick read / write
durable
Data
numbers
Binary
nibble
4 bits
byte
8 bits
KB
1000 bytes
GB
1000 MB
MB
1000 KB
TB
1000 GB
bit
1 or a 0
hex
base 16
0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
denary
base 10 number system
computers only understand binary and nothing else
sound
Sound is stored by taking regular samples and measuring the amplitude and converting it to binary and storing it. the file size is calculated by doing (duration
sample rate
bit depth)
pictures
each pixel has a colour which is turned into a binary number and stored