Hardware (paper 1) Flashcards
what is the purpose of the CPU
to continuosly process instructions and data that are input and repeatedly carrying out the fetch-execute cycle to output a result
what does CPU stand for
central processing unit
what does the CPU contain
- arithmetic logic unit
- control unit
- current instruction register
- accumalator
- memory data register
- memory address register
what is the fetch-execute cycle
the process every operation carries out goes through, regulated by a cucle of the CPU clock
describe the fetch-execute cycle
- FETCH an instruction from main memory (RAM)
- DECODE the instruction
- EXECUTE the instruction
what does the ALU (Arithmetic logic unit) do
carries out mathematical and logical operations
what does the CU (Control unit) do
coordinates all of the CPU’s actions in the fetch-decose-execute cycle and decodes instructions
what does the clock do
regulate the speed and timing of all signals and computer functions
what do the registers do
they are very small very fast memory locations, temporarily storing memory addresses, instructions or data
what do address, data and control buses do
they are wires used to transfer data, instructions, memory addresses, and control signals from one component to another
what does the clock speed determine
the number of fetch-execute cycles per second
what is cache memory
storage which is much faster than main memory beacuse it is transferred more quickly, making the CPU more efficient
how many levels of cache are there
2 or 3
what is the relationship between speed and capacity with cache memory
the fastest cache has the smallest capacity (level 1)
will the CPU use cache or RAM first
it will use the fastest level of cache before moving to the next level
what can each core do
process one operation per clock cycle
what type of code do processors execute
machine code
what is an instruction set
a processors own specific list of commands written in machine code that can be executed and understood by the CPU
what is an embedded system used for
to control the function of electronic devices, they don’t need operating systems
why do embedded systems not need operating systems
because they perform limited and very specific tasks with their imput frequency controlled by a button or switch
why must embedded systems be reliable
because they cannot be modified once manufactured - the program is held in the ROM
what does RAM stand for
random access memory
what is the function of the RAM (main memory)
to temportarily store the instructions and data the computer needs whilst it is in operation
why is the RAM needed
because it would be too slow to access everything directly from the hard drive disk
explain how the RAM is volatile
it is a temporary working memory - it gets wiped as soon as the power is switched off
what does ROM stand for
read only memory
what is the function of the ROM
stores instructions and data that never needs to be changed
give an example of what the ROM stores
the computers start up intructions so that it can turn the computer on
is the ROM volatile
no
can you read and write in the ROM
no, read only
give an example of primary storage
RAM and ROM
what is secondary storage
storage no directly accessed by the CPU
give an example of secondary storage
- USB falshdrive
- CDs
what makes solid state drives so good
they don’t have any moving parts and require very little power so are very small and very fast
what is another name given to solid state drives
flash memory
how do SSDs work (flash memory)
- they used NAND or NOR gates in electrical circuits to presistently store data
- they use transistors as control gats and floating gate to control the flow of current
what is current flowing represented by
1
what is no current flowing represented by
0
how does a optical dirve work
- uses a laser tecnology to reflect light off the reflective surface of the disk
- one long spiral track contains pits (0) and lands (1) storing the data
- when the beam hits a pit the light is refracted and a 1 is recorded
- eg, blu-ray, CDs DVDs
when is virtual memory used
when there isn’t enough space in RAM for all the data programs you are currently working on
explain virtual memory
- a small section of the hard disk is reserved to act like the RAM
- when the program in virtual emmory is needed it is swapped with something else in the RAM
- the swapping may cause a slow down
why does your computer slow while accessing the virtual memory
because it is not nearly as fast as the RAM
what is cloud storage
the remote file storage on someone else’s servers (google, microsoft)
what is needed to store data in cloud storage
physical servers and storage
what are the advantages of cloud storage compared to local storage
- no need to purchase local storage devices
- files are automatically backed up in the cloud
- greater fualt tolerace
- remote access to files from any internet connected device
- enables file sharing
what are the disadvantages of cloud storage compared to local storage
- may need to commit annual subscription
- back up may be slower dependsing on internet connection speed
- security of data wil be managed by a third party whereas primary is directly accessed by CPU
- need an internect connection to access online data
- limiter or delayed support from provider
- responsible for any security breaches over data
what are network interface cards (NIC)
something required to connect ti any netwok-enabled device - a physical component which can operate with a wireless connection or a wired connection
what is a MAC address (media access control)
used to identify a device with a unique hexadecimal identification number assigned to every network interface card
is the MAC address static
yes it stays the same
what does IP address stand for
internet protocol address
what is an IP address
a unique public address for the router or gateway of a network
how do routers use IP addresses
to direct data packets from one router to another between start and end point on a netwrok
where do routers sit
between local networks adn the internet to join them together with a public IP address fro the internet and a private IP address for the local network
who assigns the IP address for your whole network
the internet service provider
what is a static address
an address that does not change
what is a dynamic address
an address that does change and are assigned from a list of avaliable address at the time they are required
why are dynamic address used
because the IPv4 system does not have enough static addresses for everyone
what is an IPv4 address
an address wuth four numbers each seperated by a full stop
what is the problem with IPv4
the system is running out of possible addresses owing to the huge rise in networked devices
what was created to solve the IPv4 problem
IPv6
what are the cloud storage features
- synchronisaed devices
- 24/7 availability
- redundancy
define redundancy
Having more than one copy of files stored on a different hard drive or at a different location
define scalability
The ability to easily increase the size of computing storage or processing power
what is cloud storage
the storage of data on the cloud
what is cloud computing
using Word or Exel etc on the cloud
what is a server
An item of hardware which responds to requests by processing data and sending replies
what is a data centre
A centralised collection of servers stored in on building
what are the advantages and disadvantages of opticle storage
+ cheap
+ very easily portable
-easily damaged
-slow write speed
how does a hard disk drive work (magnetic storage)
- the magnetic platter contains data
- the disk contains tracks
- the dick head is mounted on mechanical arms to read and write data
- the actuator moves the arm while the spindle rotates
what is meant by an input device and why is it required
- it is a hardware device that allows data to be entered into a computer or system
- it takes the input from the user or environment and converts it so the computer can process it
- this enables interaction between computer technology and the user
- without these devices computers could not receive external data or commands
give examples of an input device
- touch screen
- keyboard
- microphone
what is meant by output device and why is it required
- hardware device that allows a computer to send data or info to the user or another systme
- converts processed data from computer into format perceived by humans [text, sound]
- without we would not be able to understand the results of a computer
give examples of output devices
- computer screen
- speakers
what is meant by a sensor and what is its purpose
sensors collect data from the environment and sent it to a computer to trigger actions or monitor conditions
what are the different type of sensors and give an example of when they should be used
- temperature sensor = thermostat, fridge, AC
- light sensor = street lighting, lights on at dusk and off at dawn
- motion sensor = security cameras, automated lighting
- humidity sensor = greenhouse
- pressure sensor = car tire, weather forecast
- proximity sensor = smartphone in call turns off touchscreen
- gas sensor = factories, homes, labs
- sound sensor = smart assistant devices, voice recognition
what is the role of a router in a network
- connects multiple networks
- directs data in most efficient path
- traffic management
- IP address assignment
what does a comouter need to access a network
a network interface card (NIC)
