1
Q
What are input devices used for?
A
- hardware components that allow users to interact with a computer system by inputting data or commands into the system for the computer to process
2
Q
What are output devices used for?
A
- hardware components that receive processed information from a computer system and present it to the user in a readable form
3
Q
What is primary memory and why is it needed?
A
- memory directly accessible by the CPU that temporarily stores data and instructions while the computer is on and running
- allows for faster fetch-execute cycles as it is closer to the CPU than the secondary storage
4
Q
What is secondary storage and why is it needed?
A
- hardware components that provide permanent data storage for accessing, retrieving, and storing data
5
Q
What are the benefits of magnetic storage?
A
- high storage capacity
- relatively low cost per gigabyte
- suitable for long-term storage and backup
6
Q
What are the disadvantages of magnetic storage?
A
- slower read/write speeds compared to solid state storage
- susceptible to physical damage, but not as badly as optical storage
- moving parts can wear out over time
7
Q
What are the benefits of optical storage?
A
- durable and relatively immune to environmental conditions
- easily portable
- suitable for distributing music, software, and movies
8
Q
What are the drawbacks of optical storage?
A
- lower storage capacity compared to other storage mediums
- can easily be scratched or damaged, risking loss or corruption of data
- slower read/write speeds compared to other storage mediums
9
Q
What are the benefits of solid state storage?
A
- fast read/write speeds
- no moving parts, so less likely to fail due to physical damage
- silent operation
10
Q
What are the drawbacks of solid state storage?
A
- high cost per gigabyte
- flash memory cells can wear out after a certain number of write cycles
11
Q
What is an embedded system?
A
- a microcontroller used to perform a dedicated function inside a larger system
12
Q
What are the benefits of embedded systems?
A
- small and compact, easy to fit into dedicated devices
- low power consumption, so efficient and cost effective
- fast and reliable as they are designed for quick, repetitive tasks
- cheap to produce as they require minimal hardware
- works in real time, ideal for sensitive operations
13
Q
What are the disadvantages of embedded systems?
A
- limited functionality, only meant for one task
- hard to upgrade or repair as they are built into the device
- limited memory and processing power
- can’t easily be reprogrammed for other tasks
- limited protection if connected to other systems, so may be less secure
14
Q
Describe how a laser printer works.
A
- laser beam draws the image of the page onto a photosensitive drum, changing its electric charge
- the toner sticks to the drum, and the toner powder is attracted to charged areas matching the image shape
- toner is transferred from the drum to the paper
- the process of fusing occurs, where the paper passes through hot rollers, which melts the toner onto the paper so it doesn’t smudge
15
Q
What is a 3D printer?
A
- a machine that builds objects layer by layer from the bottom up using materials such as thermoplastics, resin, and metals
16
Q
What are 3D printers used for?
A
- healthcare: prosthetics
- automotive/aerospace: custom parts
17
Q
What are the benefits of using 3D printers?
A
- allows high customisation and rapid prototyping
- handles complex shapes traditional methods can’t make easily
18
Q
What are the disadvantages of using 3D printers?
A
- can be slow for large/detailed objects
- some methods need costly/specialist materials
19
Q
FDM 3D printer
A
melts plastic and builds in layers
20
Q
SLA 3D printer
A
uses light to harden liquid resin
21
Q
Describe how a microphone works.
A
- allows users to record voice or send audio into a computer by converting sound waves into electrical signals
- sound waves cause vibrations of the microphone’s diaphragm
- this causes a coil to move past a magnet
- electrical signal produced
22
Q
Dynamic microphone
A
- when the sound waves cause vibrations of the mic’s diaphragm, it causes a magnet to move past a coil
- good for loud environments, used in concerts
23
Q
Condenser microphone
A
- when the sound waves cause vibrations of the mic’s diaphragm, it changes the capacitance
- more sensitive and accurate, used in studios
24
Q
Crystal microphone
A
- when the sound waves cause vibrations of the mic’s diaphragm, it deforms the crystal
- used for telephones and portable sound systems
25
Describe how speakers work.
- allows for sound to be projected by converting electrical signals into sound waves
26
Describe how magnetic hard disks work.
- multiple metal platters coated in a magnetic material store data as magnetised iron particles
- these metal platters are mounted on a spindle
- the platters are divided into concentric tracks and wedge-shaped sectors, forming track sectors, and spin at high speeds
- the read/write arm, controlled by an actuator, positions the read-write head over the correct track sector
- data is read/written using electromagnets, which cause a change in the magnetic field which then produces a change in the electric current
27
Describe how solid state memory works.
- it stores data in cells using transistors as switches and uses NAND or NOR gates to control the flow of electrons
- each cell contains a control gate that controls the current and a floating gate that stores charge
- to write data, high voltage pushes electrons onto the floating gate
- to erase data, a reverse high voltage pulls electrons off the floating gate
28
Describe how an optical disk reader/writer works.
- uses a laser moved by an arm to read/write data on optical disks
- to write data, the laser burns pits and lands onto the disk surface
- to read data, the laser scans the surface of the disk and detects changes in the reflection of the laser, which indicate 0s and 1s
29
CD-R optical disk
write once
30
CD-RW / DVD-RW
re-writeable
31
Describe how a touchscreen works.
- it detects a user's touch and converts it into an input command
32
Capacitative touchscreen
- responds to electrical charge from fingers
33
Resistive touchscreen
- responds to pressure
34
Why are touchscreens used nowadays?
- they are popular for direct, easy interaction and improved accessibility
35
Describe how virtual reality headsets work.
- it creates a fully immersive 360º digital environment using head tracking, motion sensors, and stereoscopic displays for 3D vision
- it allows users to look around and interact with the virtual world
36
What are the uses of virtual reality headsets?
- gaming
- education/training
- architecture/design
- medical/therapy
37
What are the challenges of using virtual reality headsets?
- expensive hardware
- possible eye strain or motion sickness
- time-intensive content creation
38
What is a buffer?
- a temporary storage area that holds data while it is being transferred between two devices or processes
39
How do buffers work?
1. data is collected by the buffer before being processed or output
2. when the receiving device is ready, it takes data from the buffer
40
Why are buffers needed?
- they synchronise data transfer between slow and fast devices or processes
- they improve efficiency and prevent bottlenecks
- they minimise the risk of losing or delaying data transfer if one device is not ready to process information
41
What is RAM?
- random access memory
- primary storage that directly connected to the CPU that holds data and instructions currently in use
42
What is ROM?
- read only memory
- a small memory chip on the computer's motherboard acting as primary storage holding the first start-up instructions the computer needs to start up as well as the BIOS (basic input output system)
43
Explain the differences between RAM and ROM.
- RAM is faster than ROM
- RAM has a higher capacity than ROM
- RAM stores data and instructions currently in use whilst ROM stores start-up instructions
- RAM is read and write whereas ROM is read only
- RAM is volatile whereas ROM is non-volatile
44
What is SRAM?
- static RAM
- form of RAM that keeps data as long as power is on
- uses transistors arranged as flip-flops so constant refreshing is not needed
45
What is SRAM usually used for?
- used in places where speed is more important than storage size, such as cache memory
46
What is DRAM?
- dynamic RAM
- form of RAM that stores each bit in a tiny capacitor, which are accessed and controlled by transistors
- needs constant refreshing to keep the data
47
What is DRAM usually used for?
- used in places where larger amounts of cheaper storage is needed, such as main memory (RAM)
48
Explain the difference between PROM, EPROM, and EEPROM
- PROM can be programmed once only, whilst EPROM and EEPROM can be reprogrammed multiple times
- PROM cannot be erased; EPROM is erased by UV light; EEPROM is erased by electric voltage
- EPROM must be removed from its device to be erased whereas this is not a requirement for EEPROM
- EPROM's entire chip gets wiped when it is erased whilst specific parts of EEPROM can be erased as needed
- PROM is commonly used for firmware; EPROM is commonly used for reprogrammable chip development; EEPROM is commonly used for flash memory and BIOS chips
49
Explain the differences between SRAM and DRAM.
- SRAM is faster than DRAM
- SRAM uses less power and is better for low-power devices; DRAM uses more power due to its constant refresh cycles
- SRAM is more expensive to make compared to DRAM because it prioritises speed
- SRAM takes up more space and has a lower storage capacity than DRAM
50
What are monitoring systems?
- a system used to collect data continuously through passively gathering data, designed for high accuracy using precise sensors and measurements
- it does not interact with or change the environment
- it does not take action based on the collected data
51
What are control systems?
- a system used to automatically manage or adjust a process based on data collected from sensors designed to keep systems stable, safe or working efficiently without human input
- works by monitoring input, then taking action if certain conditions are met
- they interact with the environment
52
What are sensors?
- input devices that measure a physical property of their environment
53
List down some sensors and their typical use
- temperature: used to maintain temperature in swimming pools
- pressure: can be for gas/liquid/physical pressure; typically used for monitoring tire pressure and pressure in pipes during the manufacturing process
- infrared: detects motion or a heat source; typically used for security systems detecting intruders who break the beam of radiation as well as for measuring heat radiation for emergency services to detect living creatures
- sound: converts sound waves into electrical signals that computers can process, typically used for voice recognition and security systems
54
What is a feedback loop?
- a process where a control system's outputs are recycled and used as inputs, creating a continuous cycle
- allows the system to automatically adjust and stay within set conditions
55
Why is feedback important?
Allows the system to check if it is working as expected
CS a levels
flashcards
Decks in class (11)
# Cards
-
Chapter 1 - Information Representation71
-
Chapter 2 - Networks & The Internet146
-
Chapter 3 - Hardware55
-
Chapter 5 - System Software39
-
Chapter 4 - Processor Fundamentals56
-
Chapter 6 - Security, Privacy, and Integrity40
-
Chapter 12 - Software Development34
-
Chapter 7 - Ethics & Ownership33
-
Chapter 8 - Databases23
-
Chapter 10 - Data Types & Structures49
-
Chapter 9 - Algorithm Design & Problem Solving3
