3.3 data storage and compression Flashcards
1
Q
what is primary storage
A
directly accessed by CPU. RAM and ROM
2
Q
what is ROM
A
- small piece of memory located on motherboard
- contains startup instructions for computer
- non volatile
3
Q
what is RAM
A
- primary storage directly connected to CPU, hold data/instructions currently in use
- volatile
- very fast
- data can be read from/written to
4
Q
why do you need primary storage
A
- access time faster than secondary
- quicker FDE cycle
5
Q
what is ROM
A
- small memory chip located on computers motherboard
- primary storage that holds first instructions computer needs to start up (bootstrap)
- contains BIOS
- non-volatile
- read-only
6
Q
what is secondary storage
A
not directly accessed by CPU, necessary for more permanent storage of data
7
Q
how does magnetic storage work
A
- use platters divided into tracks and sectors
- data read/written using electromagnets
8
Q
example of magnetic storage
A
hard disk drive
9
Q
advantages of magnetic storage
A
- cheap
- fast
- hold large amounts of data
10
Q
how does optical storage work
A
- use lasers to create and read pits (low) and lands (high)
- land reflect, pits scatter. detected by light sensor
11
Q
examples of optical storage
A
- compact disks (CDs)
- digital versatile disks (DVDs)
- blu-ray disks
12
Q
features of optical storage
A
- low storage
- slow access to data
13
Q
how does solid-state storage work
A
use NAND or NOR technology. transistors used as control gates and floating gates. state of transistors represent binary (hold charge?)
14
Q
types of solid state storage
A
- solid state drives (SSDs)
- memory cards
- USB flash drives
15
Q
features of solid-state storage
A
no moving parts: more durable
20
Q
Diagram for virtual memory
A
