1.2 Memory and Storage Flashcards
What is a character set
A table of all characters that a computer understands
How many bits does ASCII use
7bits, 8 if upgraded
How many bits are in Unicode
16bits
What languages can Unicode represent
All + symbols
What is metadata
Data about data
What are the 3 base number sets
- hexadecimal( hex ) ( base 16 )
- binary ( base 2 )
- deanery ( base 10 )
What are the 3 types of secondary storage
- optical
- solid state
- magnetic
Ho does solid state work
Electric circuits- no moving parts
How does magnetic storage work
Uses spinning disks and arm that reads magnatism
How does optical storage work
Uses a light/laser to read small indents in disks
What is the equation for sound file size
Bit depthsample rateduration
What is bit depth in sound
Measure the frequency at different sample points
What is sample rate
Number of samples per second
What is bit dearth in an image
Number of bits needed to represent all colours in an image
What is a pixel
Smallest amount of colour that can be represented using binary
What is the equation of file size of an image
Bit depth * resolution
What is the difference between secondary storage and private storage
All secondary storage is non volatile
What are the 2 types of primary storage
ROM + RAM
What does ROM hold
- Bootstrap
- BIOS
What does ROM stand for
Read Only Memory
What does RAM hold
Currently running programs and data
What does RAM stand for
Random Access Memory
What are the 6 characteristics of secondary storage
- durability
- portability
- reliability
- costs
- speed
- capacity
What is the definition of durability
How much it can withstand physical shock
What is the definition of portability
How easy it is to transport
What is the definition of reliability
How often it can work on a day to day basis
What is the definition of cost
How much a device costs per GB
What is the definition of speed
How quickly it can read/write
What is the definition of capacity
How much it can store
What is lossy compression
Compression that gets rid of unnecessary data to reduce the file size by a large amount ( irreversible )
What is lossless compression
Compression that doesn’t lose any data, reduces file size by not a lot. Groups things together using an algorithm
What do binary shifts do
Multiplying/dividing by 2. Moving binary digits left or right
