Hardware (paper 1) Flashcards
1
Q
what is the purpose of the CPU
A
to continuosly process instructions and data that are input and repeatedly carrying out the fetch-execute cycle to output a result
2
Q
what does CPU stand for
A
central processing unit
3
Q
what does the von nnuman machine contain
A
- arithmetic logic unit
- control unit
- current instruction register
- accumalator
- memory data register
- memory address register
- CPU
4
Q
what is the fetch-execute cycle
A
the process every operation carries out goes through, regulated by a cucle of the CPU clock
5
Q
describe the fetch-execute cycle
A
- FETCH an instruction from main memory (RAM)
- DECODE the instruction
- EXECUTE the instruction
6
Q
what does the ALU (Arithmetic logic unit) do
A
carries out mathematical and logical operations
7
Q
what does the CU (Control unit) do
A
coordinates all of the CPU’s actions in the fetch-decose-execute cycle and decodes instructions
8
Q
what does the clock do
A
regulate the speed and timing of all signals and computer functions
9
Q
what do the registers do
A
they are very small very fast memory locations, temporarily storing memory addresses, instructions or data
10
Q
what do address, data and control buses do
A
they are wires used to transfer data, instructions, memory addresses, and control signals from one component to another
11
Q
what does the clock speed determine
A
the number of fetch-execute cycles per second
12
Q
what is cache memory
A
storage which is much faster than main memory beacuse it is transferred more quickly, making the CPU more efficient
13
Q
how many levels of cache are there
A
2 or 3
14
Q
what is the relationship between speed and capacity with cache memory
A
the fastest cache has the smallest capacity (level 1)
15
Q
will the CPU use cache or RAM first
A
it will use the fastest level of cache before moving to the next level
16
Q
what can each core do
A
process one operation per clock cycle
17
Q
what type of code do processors execute
A
machine code
18
Q
what is an instruction set
A
a processors own specific list of commands written in machine code that can be executed and understood by the CPU
19
Q
what is an embedded system used for
A
to control the function of electronic devices, they don’t need operating systems
20
Q
why do embedded systems not need operating systems
A
because they perform limited and very specific tasks with their imput frequency controlled by a button or switch
21
Q
why must embedded systems be reliable
A
because they cannot be modified once manufactured - the program is held in the ROM
22
Q
what does RAM stand for
A
random access memory
23
Q
what is the function of the RAM (main memory)
A
to temportarily store the instructions and data the computer needs whilst it is in operation
24
Q
why is the RAM needed
A
because it would be too slow to access everything directly from the hard drive disk
25
explain how the RAM is volatile
it is a temporary working memory - it gets wiped as soon as the power is switched off
26
what does ROM stand for
read only memory
27
what is the function of the ROM
stores instructions and data that never needs to be changed
28
give an example of what the ROM stores
the computers start up intructions so that it can turn the computer on
29
is the ROM volatile
no
30
can you read and write in the ROM
no, read only
31
give an example of primary storage
RAM and ROM
32
what is secondary storage
storage no directly accessed by the CPU
33
give an example of secondary storage
- USB falshdrive
- CDs
34
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
35
what is another name given to solid state drives
flash memory
36
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
37
what is current flowing represented by
1
38
what is no current flowing represented by
0
39
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
40
when is virtual memory used
when there isn't enough space in RAM for all the data programs you are currently working on
41
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
(Hard disk drive)
42
why does your computer slow while accessing the virtual memory
because it is not nearly as fast as the RAM
43
what is cloud storage
the remote file storage on someone else's servers (google, microsoft)
44
what is needed to store data in cloud storage
physical servers and storage
45
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
46
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
47
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
48
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
49
is the MAC address static
yes it stays the same
50
what does IP address stand for
internet protocol address
51
what is an IP address
a unique public address for the router or gateway of a network
52
how do routers use IP addresses
to direct data packets from one router to another between start and end point on a netwrok
53
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
54
who assigns the IP address for your whole network
the internet service provider
55
what is a static address
an address that does not change
56
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
57
why are dynamic address used
because the IPv4 system does not have enough static addresses for everyone
58
what is an IPv4 address
an address wuth four numbers each seperated by a full stop
59
what is the problem with IPv4
the system is running out of possible addresses owing to the huge rise in networked devices
60
what was created to solve the IPv4 problem
IPv6
61
what are the cloud storage features
- synchronisaed devices
- 24/7 availability
- redundancy
62
define redundancy
Having more than one copy of files stored on a different hard drive or at a different location
63
define scalability
The ability to easily increase the size of computing storage or processing power
64
what is cloud storage
the storage of data on the cloud
65
what is cloud computing
using Word or Exel etc on the cloud
66
what is a server
An item of hardware which responds to requests by processing data and sending replies
67
what is a data centre
A centralised collection of servers stored in on building
68
what are the advantages and disadvantages of opticle storage
+ cheap
+ very easily portable
-easily damaged
-slow write speed
69
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
70
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
71
give examples of an input device
- touch screen
- keyboard
- microphone
- key pad
- QR scanner
- buttons
- sensors
72
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
73
give examples of output devices
- computer screen
- speakers
- headphones
74
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
75
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
76
what is the role of a router in a network
- connects multiple networks
- directs data in most efficient path
- traffic management
- IP address assignment
77
what does a comouter need to access a network
a network interface card (NIC)
78
What technologies can be used for touchscreen
- resistive
- infrared
- capacitive
79
Describe how resistive technology works for a touch screen
- the screen is made up of multiple layers
- the user pushes the top layer into the other layers beneath it
- this creates a circuit
- allowing energy to flow
- allowing the location of he users touch to be calculated
80
What are the benefits of resistive technology
- waterproof
- cheap to buy/manufacture
- does not easily shatter
- low power consumption
81
What are the drawbacks of resistive touch screen technology
- prone to scratches
- lower resolution
- not very touch sensitive
82
Does the RAM have moving parts
No
83
What is the only primary storage
RAM and ROM and cache and registers
84
Explain how a keyboard works
When a key is pressed on a keyboard a peg under the key is pressed into a springy layer to make contact with a conducting membrane
85
Explain how mice work as an input device
Uses red LED and sensor to determine the movement of the mouse relative to a surface. The speed and distance is analysed by a processor to create the same movement on the cursor
86
Explain how infra-red touch screens work
- LED shine infrared light across the screen from the top and sides
- this makes a grad across the screen
- when the screen in touched, the beams are interrupted
- a microprocessor calculates the coordinates of where the screen was touches
87
Explain how capacitive touch screens work
- made up of layers of glass
- the bottom surface of the upper layer and top surface of the bottom layer are coated with transparent conductive material
- this forms a grid
- screen stores electrical energy
- when touched, there is a change in the electrical field
- microprocessor calculates position where the field changed
88
What type of touch screen do smart phones have and why
Capacitive - allows for multi touch
89
What are the two different types of screens
- liquid crystal display = made from millions of pixels which turn on and off to make an image
- light emitting diode screens = uses light from LEDs (sports stadiums, concerts)
90
What are the different types of projectors
- digital light processing projector = millions of min to mirrors that change the intensity of colour
- liquid crystal display = uses light theee mirror filters combined to procure full colour images
91
What are the benefits of the different types of projectors
- digital light processing projector = higher contrast and definition, smoother video, smaller
- liquid crystal display = cheaper, quieter, less power output
92
Is the bootloader firmware
Yes
93
What is firmware run on
The ROM
