1.1 Primary VS Secondary Memory Flashcards
What is Primary memory ?
Storage directly accessible from the CPU.
Volatile.
What is Volatile Memory ?
Storage that loses its data when turned off.
What is a Register ?
High speed memory built into a CPU.
What is CPU Cache ?
Used to store frequently used data.
What is RAM ?
Used to store open programs.
Much slower
than the clock.
What is Read Only Memory (ROM) ?
Fast, cheap, memory that cannot be changed.
What are some Facts of ROM ?
- Starts up quickly
- Non-volatile
- Cannot be changed
- Usually cheap
What are some uses of ROM ?
- Storing boot instructions
- Storing operating systems
- Running embedded systems
How does a Magnetic Disk work ? ( 3 points)
- Metal disks are coated with magnetic material.
- This can be positively or negatively charged.
- The disks are rotated and an arm moves to the
desired location to read a positive (1) or
negative (0) charge.
How does a Optical Disk work ? ( 3 points)
- Pits (holes) and lands (flats) are burned into a
disc. - The disc is spun to find the desired memory
location. - Light is shined onto the disc. If it’s reflected by
a land, it registers as a 0. If not, it’s a 1.
How does a Solid State Drive (Flash memory)(SSD) work ? ( 3 points)
- Electrons are pushed through a gate with an
electric charge. - A 1 is recorded if there are any electrons
through the barrier. - Each cell can be checked for 1 or 0.
What is Cloud Storage ? (3 points)
- Usually magnetic disk storage.
- Backed up in several locations.
- Just somebody else’s computer.
What is Virtual Memory ?
Using secondary storage as RAM.
How does Virtual Memory work ? (3 points)
- A portion of RAM is copied to secondary
storage. - That portion is overwritten.
- When the data is needed, it is copied back
from secondary storage.
List the 6 characteristics of secondary storage.
*Cost
*Capacity
*Speed
*Reliability
*Portability
*Durability
