Section 2: Storage Flashcards
what is primary storage?
- very quick as it’s directly assessed by the CPU
- smaller in storage size
- RAM and ROM
what is secondary storage? (3)
- larger in storage size
- slower
- non-volatile
what is volatile storage?
temporary data is lost whenever the power is turned off
eg RAM
what is non-volatile storage?
saves the data even when not powered
data can be stored
long term
eg ROM
why do computers need primary storage?
accessing primary storage is much faster than secondary storage devices
what are the 2 types of primary storage?
RAM and ROM
what is RAM?
volatile
stores all the programs currently running
what is ROM?
non-volatile and can’t be changed
stores BIOS
what is virtual memory?
if there is insufficient memory
what are some storage characteristics i should know? (4)
capacity
durability
portability
cost
reliability
what is a magnetic hard disk drive? (3)
larger capacity
cheaper cost per GB than SSD
slower access speed than SSD but faster than optical
what is optical storage? (4)
- low capacity
- not durable
- has the slowest access speed
- discs are very thin and portable
what is a solid state storage? (5)
most expensive cost per gb
usually durable
small size means portable
high capacity and faster access speed
why do computers use binary?
computer systems consist of billions of tiny transistors which are switches that only have 2 values 1/0
therefore data is represented dis way
what is a kilobyte?
1000 bytes
what is a megabyte?
1000 kilobytes
(1000 x 1000 bytes)
what is a gigabyte?
1000 megabytes
(1000 x 1000 x 1000 bytes)
what is a terabyte?
1000 gigabytes
(1000 x 1000 x 1000 x 1000 bytes)
what is a petabyte?
1000 terabytes
(1000 x 1000 x 1000 x 1000 x 1000 bytes)
what is the order of bits?
byte
kilobyte
megabyte
gigabyte
terabyte
petabyte
what is an overflow error?
occurs when a binary value is too large to be stored in the bits available
what is a character set?
is a table that matches together a character and a binary value
each character in a character set has a unique binary matched with it
what does ASCII stand for?
American Standard Code for Information Interchange
1 byte - 8 bits
what is unicode?
2 bytes - 16 bits
allows different languages to be represented; emojis, symbols