memory Flashcards
primary storage
volitaile with the exception of rom
computers beed primarily storage because access times are faster
primarily storage holds data and instructions
primary storage is used as short term working memory
secondary storage
non volatile
large capacity
what is ram
ram is primary storage that holds data and instructions that are currently in use
ram is volatile
ram is very fast
ram is read/write which means data can be read from and written to
what is rom
rom is primary storage that holds the first instructions a computer needs to start up
rom contains the bios
rom is fast memory but slower than ram
rom is non volatile
rom is read only
what is virtual memory
virtual memory is an extension of primary storage located on secondary storage
when ram is nearly full virtual memory is used
programs and data not currently being excuted are transferred to virtual memory
slower than ram
why do you need secondary storage
long term storage of programs and data not currently in use
slower than primary storage but capacity is much higher
common types of storage
magnetic
solid state
optical
what is magnetic storage
magnetic storage is a type of non volatile media that uses magnets to store binary 0s and 1s
advantages and disadvantages of magnetic storage
advantages
high capacity
low cost per gb
decent speed
disadvantages
not very durable
inconvenient to be portable
not very reliable
and noisy
what is solid state storage
solid state storage is a type of non volatile media that used electronic circuits to store binary 0s and 1s
advantages and disadvantages of solid state storage
advantages
high storage
very fast
durable
portable
disadvantages
high cost
not reliable
optical storage what is it
optical storage is a type of non volatile media that uses lasers to burn the surface of a disk creating pits and lands suitable for storing binary 0s and 1s
advantages and disadvantages of optical storage
advantages
low cost
durable
protable
disadvantages
low capacity
slow
not reliable
from smallest to largest the units of storage
bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte
4 bits make a nibble
8 bits makes a byte
1000 bytes is a kilo byte
1000 kilo bytes is a megabyte
1000 megabytes is a giga byte
1000 gigabytes is a terabyte
1000 terabytes is a petabyte
hexadecimal values
A=10
B=11
C=12
D=13
E=14
F=15