3 Hardware Flashcards
What is a CPU?
A component in a computer system that processes data and instructions.
What is a microprocessor?
an integrated circuit that is able to perform many of the functions of a CPU.
What is an embedded system?
a computer system that performs a dedicated function.
What is the fetch-decode-execute cycle?
the cycle through which data and instructions are processed.
What is the role of a CPU in a computer?
The CPU processes instructions and data that are input into the computer so that the result can be output.
What is the role of busses?
Carry data through components.
What is RAM?
Random Access Memory is a component in the CPU that holds data and programs that are currently in use.
What is hard drive?
a storage that stores data permanently, until it is deleted by the user.
What are the units in a computer that has von neumann architecture?
Arthimetic logic unit (ALU)
Control Unit (CU)
What is CU?
Control Unit. The component in the CPU that controls all the operations in the CPU.
What are the registers in a computer that has von neumann architecture?
- Program Counter (PC)
- Memory Address Register (MAR)
- Memory Data Register (MDR)
- Current Instruction Register (CIR)
- Accumulator (ACC)
What are the buses in a computer that has von neumann architecture?
- Address bus
- Data bus
- Control Bus
What is PC?
Program counter is a component in the CPU that stores the next address of the next instruction to be processed.
What is CIR?
Current instruction register. Stores the instruction the CPU is currently decoding or executing.
What is MDR?
A component in the CPU that stores the data or instructions that are fetched from the RAM.
What is ACC?
Accumulator. A register that is built into the ALU. During calculations, data is temporarily held in it.
What is ALU?
Arithmetic Logic Unit. The component in the CPU that performs all the mathematical and logical operations required when processing data and instructions.
What is address?
A memory location in RAM.
What is MAR?
Memory Address Register is a component in the CPU that holds the address of the data or instruction to be located in RAM.
What is address bus?
Wires used for the transmission of addresses between components in a computer.
What is the data bus?
wires used for the transmission of data and instructions between components in a computer.
What is a control bus?
wires used for the transmission of control signals between components in a computer.
Can you describe the process of the FDE cycle including the role of each component in the process?
- PC contains the address of the next instruction to be fetched.
- This address is copied to the MAR via the address bus
- The instruction of the address is copied into the MDR temporarily
- The instruction in the MDR is then placed in the CIR.
- The value in the PC is incremented by 1, pointing to the next instruction to be fetched.
- Instruction is decoded by CU.
- It is then executed by the ALU and the result is stored in the ACC or written to a memory location within memory.
What are the 3 main factors that can affect the performance of a CPU?
- Number of cores
- Clock speed
- Size of cache
What is meant by a core?
the part of the CPU that contains all the components that are used to perform the fetch-decode-execute cycle.
Each core runs seperate FDE cycles, independently from each and at the same time. This means parallel processing can take place.
What is clock speed?
the number of fetch-decode-execute cycles that can be performed in a second.
What is clock speed measured in?
Hertz.
How many instructions are 1gigahertz and 1 megahertz?
1 Gigahertz(GHz) = 1 billion instructions per second
1 Megahertz(MHz)= 1 million instructions per second
What is meant by cache?
a type of storage that is built into the CPU, to store the most frequently used data and instructions.
How can cores affect CPU performance?
The more cores in the CPU, the more instructions that can be executed per second resulting in better performance.
eg. Dual cores = 2 cores, Quad cores = 4 cores
How can clock speed affect CPU performance?
By increasing clock speed, the computer’s processing speed also increases, this doesn’t mean the computer’s performance is increased however.
How can cache affect CPU performance?
The impact of increasing the amount of cache is that more data can be stored there and accessed faster if it was in the RAM, which improves the performance of the CPU.
What is an instruction set?
It is a list of all the commands that can be processed by a CPU and the commands are machine code.
Each command has a unique binary code
What is an embedded system?
An embedded sytem is a computer system with either one function or limited specific functions built within a larger mechanical device.
What is the purpose of an embedded system?
It is used to perform a dedicated function, eg. domestic appliances, lighting systems. This is different from a general purpose computer that is used to perform many different functions.
Can you identify devices in which embedded systems are commonly used?
- Digital Clock
- Traffic Lights
- Lighting System
- Vending Machine
What is an output device?
a device that can be used to obtain the results of data that has been processed.
What is an input device?
A device that allows data to be entered into a computer system.
What are some examples of input devices?
- barcode scanner
- digital camera
- keyboard
- microphone
- optical mouse
- QR code scanner
- Scanner (2d and 3d)
- touch screen
What is a sensor?
A type of input device that is used to capture data from its immediate environment.
What is an automated system?
a system that is designed to operate without the need for any human intervention.
What are the example uses and benefits of a barcode scanner?
Example Uses:
* checkouts
* parcel deliveries
Benefits:
* faster checkouts
* less errors
* detailed stock info
What are the example uses and benefits of a digital camera?
Example Uses:
* Smartphones
* security systems
* Cameras
Benefits:
* instant preview and image
What are the example uses and benefits of a keyboard?
Example Uses:
* Entering text
Benefits:
* Universal
* Easy to use
What are the example uses of a microphone?
Example Uses:
* Recording real-world sound
* Musical recordings
* Telephone calls
What are the example uses and benefits of a mouse?
Example Uses:
* Navigating a GUI
* Making selections and entering commands
Benefits:
* Intuitive
What are the example uses and benefits of a QR code scanner?
Example uses:
* Advertising products
* Linking to websites
* e-tickets
Benefits:
* Can hold more information than a barcode
* No need for user to write down website address, can be scanned using camera on a mobile device
What are the example uses and benefits of a scanner?
Example Uses:
* Scan documents, photos AIRPORT
* Scan objects (3D only)
Benefits:
* Converts 2D and 3D objects into digital data which is easier and quicker to transmit, duplicate or manipulate.
What are the example uses and benefits of touchscreens?
Example Uses:
* Cash machines
* Info screens
* Entering text and commands on mobile devices
Benefits:
* Can be durable
* Good image quality
* Intuitive/ Easy to use.
What are some examples of output devices?
- actuator
- digital light processing (DLP) projector
- inkjet printer
- laser printer
- 3d printer
- LED screen
- LCD screen
- LCD projector
- speaker
What are example uses of actuators and when are they used?
Example Uses:
* starting or stopping a pump
* moving robotic arms
* opening or closing a valve.
They are often used with sensors. The input of the sensor is checked against stored values and a decision is taken.
What is the use of a light projector and what are the 2 types of light projectors?
Used to project computer outputs onto a large screen.
The two types are- DLP (Digital Light Processing) and LCD (Liquid Crystal Display).
What are the advantages and disadvantages of a DLP?
Advantages:
* Higher reliability
* Smaller and lighter
* Higher contrast ratios- Smooth video
Disadvantages:
* Image tends to suffer from “shadows” when showing a moving image
* The colour definition is not as good as LCD projectors
What are the advantages and disadvantages of LCDs?
Advantages:
* Give a sharper image than DLP projectors
* Better colour saturation and intensity than DLP projectors
* Use less power and generate less heat
Disadvantages:
* Have a limited life
* Contrast ratios are not as good as DLPs
* LCD panels degrade over time.
What is the use of laser and inkjet printers and when are they used?
Both printers create hard copies of a digital document.
They are used when hard copies are needed but you do not have access to an electronic device.
What are the uses of 3D printers?
Create 3D modles of a digital model by depositing layers of material on top of one another.
Used in architecture.
What are uses the advantages of LCD screens?
Used in TVs. monitors, tablets and phones.
Advantages:
* low power consumption
* run at cool temperature
* do not suffer image burn or flicker issues
* provide bright images and colours
* cheaper to produce than LED screens.
What are the uses and advantages of LEDs?
Uses include: Replacing LCD displays in TVs, monitors, laptops and mobile devices.
Advantages:
* better image quality
* longer life span
* can be used to create very large screens
* consume very little power.
What are the uses of speakers?
Typical uses include listening to music, listening to video sound, telephone calls and alarms.
How does a sensor work?
Sensors are used to capture analogue data from its immediate surroundings. This data can then be processed and analysed by a computer system. Sensors are normally set to capture data at given time intervals.
What are the 14 sensors?
- acoustic
- accelerometer
- flow
- gas
- humidity
- infra-red
- level
- light
- magnetic field
- moisture
- pH
- pressure
- proximity
- temperature
What does an acoustic sensor measure and what is it’s typical use?
It measures sound levels
The typical uses are:
* monitor noise pollution
* detect changes in sound levels of industrial machinery
What does an accelerometer sensor measure and what is it’s typical use?
It measures: acceleration rate, tilt, vibration
Its typical uses are:
* detecting sudden changes in vehicle movement and deploy safety features if needed
* in mobiles to detect orientation of the device.
What does a flow sensor measure and what is it’s typical use?
it measures: rate of gas, powder or liquid flow.
Its typical use is:
* Detect changes in the flow through pipes in water system
What does a gas sensor measure and what is it’s typical use?
Measures: presence of a gas e.g. carbon monoxide
Its typical use is:
* Detect levels of gas in confined spaces
* Detect gas levels when fixing gas leaks
What does a humidity sensor measure and what is it’s typical use?
Measures: levels of water vapour
Its typical uses:
* Monitor humidity in greenhouses
What does an infra-red sensor measure and what is it’s typical use?
Measures: Detecting motion or a heat source
Its typical uses are:
* Security systems detecting intruders who break the beam
* Measures heat radiation of objects - used by emergency services to detect people
What does a level sensor measure and what is it’s typical use?
Measures: liquid levels
Its typical use:
* Detects levels of petrol in a car tank
* Detect levels of water in a water tank
What does a light sensor measure and what is it’s typical use?
Measures: Light levels
It’s typical uses:
* Automatically switching on lights when it gets dark (street lights, headlights)
What does a magnetic field sensor measure and what is it’s typical use?
Measures: Change in magnetic fields
It’s typical uses:
* counting how many cars pass through a certain area as the cars will disrupt the Earth’s naturally magnetic field as it passes over the sensor.
* monitoring rotating machinery such as wind turbines.
What does a moisture sensor measure and what is it’s typical use?
Measures: Presence and levels of moisture
Its typical uses:
* Monitoring moisture in a soil
* Monitoring damp in buildings
What does a pH sensor measure and what is it’s typical use?
Measures: acidity or alkalinity
Its typical uses:
* Monitoring soil to ensure optimum growing conditions
* Monitor pHlevels in chemical processes
What does a pressure sensor measure and what is it’s typical use?
Measures: Gas, liquid or physical pressure
It’s typical uses:
* Monitoring tyre perssure
* Monitoring pressure in pipes during manufacturing process
What does a proximity sensor measure and what is it’s typical use?
Measures: Distance
Its typical uses:
* Monitoring position of objects in robotics
* Used in safety systems to prevent objects colliding
What does a temperature sensor measure and what is it’s typical use?
Measures: Temperature in Celsius, Fahrenheit or Kelvin
It’s typical uses:
* Used to mantain temp in swimming pools
* Used to control temp in chemical processes.
What is primary storage?
Directly accessible by the CPU, includes RAM, Cache and ROM
What is the role of RAM?
Is to store data, instructions and software currently in use.
What are the characteristics of RAM?
- Volatile/temporary memory. If power is turned off, contents of RAM are lost.
- Used to store; data and programs currently in use by the computer.
- It can be written to or read from and the contents can be changed.
What is ROM?
A type of primary storage that stores the start up instruction for a computer.
What are the characteristics of ROM?
- Non volatile/permanent storage. Contents of ROM are retained even if power is removed.
- It stores programs that initially boot the computer, such as bootstrap and the BIOS.
- Contents of ROM are fixed and do not normally change. It is possible to reprogram it but this is complex.
What is secondary storage?
A type of storage that is designed to store data permanently until it is deleted by the user. It is not directly accessible by the CPU.
What are the 3 main types of secondary storage?
- Magnetic storage
- Optical storage
- Solid-State Storage
What is magnetic storage?
a type of secondary storage that uses the properties of magnetism to store data.
What is optical storage?
A type of secondary storage that uses lasers to store data.
What is solid-state storage?
A type of secondary storage that uses transistors to store data.
How does magnetic storage work and give an example of magnetic storage?
- have platters that spin to allow data to be read and written.
- Each platter is divided into tracks and sectors.
- A read/write head arm controlled by an actuator moves across the platter.
- Arm Reads/Writes data using electromagnets.
- Uses electromagnets to magnetize dots one each platter.
- Magnetic fields of dots determine binary value.
Example is: Hard Disk Drive
Why are solid state drives increasingly popular in place of HDD/Magnetic Storage?
- Durability
- Lower Power consumption
- High-read/write speeds
- More reliable (No moving parts)
- Lighter
What are examples of optical storage and each one’s features?
-
Blu-rays
have the largest capacity -
CDs
lowest capacity -
CD-R
are read-only -
CD-RW
can be written to and read from -
DVD-RW
can be written to or read from
How do optical storage devices operate?
- Work by shining a laser at the disk and processing the reflection.
- An arm moves the laser across the surface of the disk.
- in CD-Rs a laser burns the data, permanently on to the disk, by creating pits and lands.
- The laser is also used to read the data from the pits and lands.
- In CD-RW the chemical composition of the disk is changed to represent 0s and 1s. This change can be overwritten.
What are the benefits of optical device storage?
- High storage capacity compared to magnetic storage devices.
- Fast data transfer rates
- Considerable degree of durability
How do solid-state storage devices operate to store data and give an example?
- Storage is made of transistors that are arranged in a grid layout.
- Uses NAND or NOR gates in electrical circuits to persistently control the flow of electrons.
- Current flowing is 1, no current is 0- which is how electrical flow can represent binary values.
- A NAND gate will take in two inputs and produce an output(1/electrical current) as long as both inputs are not 1.
- A NOR gate will produce an output(1) only when both inputs are 0
Examples are: USB flash drives, solid state drives for mobiles
What are the drawbacks of solid state storage devices?
-
Storage capacity
Traditional hard drives offer more storage at lower cost. -
Data recovery limitations
Recovering data from a damaged or failed solid-state drive can be more challenging compared to traditional hard drives.
What is virtual memory?
a type of memory that can be used as an extension to RAM.
What is the purpose of virtual memory?
Amount of physical RAM available is limited. Some programs are larger than this.
- Extends the RAM capacity
- It prevents the system from crashing
- It allows the computer to process large amounts of data required
What is cloud storage?
data storage that is owned by a third party and accessed by the user using the internet.
What is a server?
A component that acts as a central resource for the storage of data and applications or for providing a service.
What are the advantages of cloud storage over storing data on a local secondary storage device?
- Accessibility
- Data can be accessed from anywhere
- Data can be accessed by anyone with revelent persmissions making it quicker to share files.
- Scalability
- Cloud storage providers allow customers to increase or decrease their storage capacity as needed.
-
Reliability
-Cloud storage providers often use multiple servers to store and back-up data, reducing the risk of data loss due to hardware failure. -
Security
-Cloud storage providers offer advanced security features, such as data encryption, multi-factor authentication to protect user data from unauthorized access.
What are the disadvantages of cloud storage?
- Slow or unreliable internet connection would mean problems accessing files.
- storing a lot of data can be expensive
_ pay the cloud storage provider
_commit to an annual subscription
_pay for high download and upload data transfer limits. - Data being sent over the internet can be intercepted.
- Security is managed by cloud storage provider which means user does not have complete control over it but is still legally responsible for ensuring any personal and sensitive data is secure.
What is a network?
computers and devices that are joined together using cables or wireless technology
