1 Digital devices Flashcards
Define mainframe computer
Large, powerful computer that can do a lot of jobs quickly
Define microprocessor
Device that controls what a computer does - takes data as input and provides output
E.g. in washing machines
Define peripheral
Equipment that is connected to a computer and used with it
State the advantages of desktop computers
- More space for components than laptops
- Provide users with the option to upgrade them or add additional components
- Less expensive to upgrade
- Monitors can come in many sizes
State the advantages of desktop computers
- More space for components than laptops
- Provide users with the option to upgrade them or add additional components
- Less expensive to upgrade
- Monitors can come in many sizes
State the disadvantages of desktop computers
- Require peripheral devices - monitor, mouse, keyboard
- Not portable - has to be connected to mains supply
- Takes up more space
- Loose cables - untidy and trip hazard
State the advantages of laptops
- Portable - has keyboard, screen, trackpad
- No need for peripherals - cheaper
- No loose cables - tidy and no trip hazard
State the disadvantages of laptops
- Limited battery life
- More expensive to repair and upgrade
- Can be stolen or lost more easily
What is a mobile phone SIM card used for?
To connect to a mobile phone network
To identify the subscriber to a mobile phone network
Define smartphone
Small computers with Wi-Fi and mobile phone connectivity to allow them to make phone calls and access the internet
Define Wi-Fi
A way of connecting computers or other electronics to a network or the internet by using radio signals rather than wires
Define application
A program that allows a user to perform a task
State the advantages of smartphones
- Multi-functional
2. Easy internet access
State the disadvantages of smartphones
- Shorter battery life - combine many features so use more power
- More expensive than other mobile phones
What effects do high and low frame rates produce?
High frame rates produce smooth results
Low frame rates produce results that appear to stutter or jump
Define resolution
The number of pixels used by a screen to display an image
What is the difference between smart TVs and normal ones?
Smart TVs use apps and can download and stream content from the internet
What do sound systems produce?
Loud, rich sound using high-quality speakers and amplifiers
electronic device that increases the voltage, current, or power of a signal
Define Blutooth
Wireless connectivity that allows devices to connect over short distances
Define personal video recorder
Device that records broadcasted content so that it can be watched at a later date
What are Blu-ray and DVD players used for?
To connect to TVs to play films and other content that is stored on DVD or Blu-ray disks
What is the advantages of Blu-ray players rather than DVD players
Blu-ray players will usually play DVD disks, but DVD players will not play Blu-ray disks
Blu-ray disks can store HD movies - higher quality pictures and sound
What do game consoles do?
Enable users to play video games on a television screen
What are the disadvantages of handheld consoles?
Less storage
Reduced image and sound quality
Reduced game complexity and limited storylines - reduces amount of data
What are media players?
Provide video and audio content to a television (e.g. Apple TV)
Wired and wirelessly
Can be controlled using a remote or smartphone app
What are the advantages of media players?
Compact, portable with local storage to hold files
Long battery life
Often use solid state flash memory - not affected by being moved or shaken
Define flash memory
Form of storage that stores data as electrical charges held in tiny electrical cells
Explain how navigation aids work
- Use information from GPS satellites to determine exact location of device on Earth
- Use orientation sensors to know which way the device is pointing, and this is displayed on a map
Define GPS
The global positioning system that uses radio signals from satellites to show your exact position on the Earth
Define multifunctional device
A device that can perform many functions
Define connectivity
Device’s ability to connect to networks and other devices
Define portability
How easy it is to carry a device around
Define performance
How fast of slow a device completes its tasks
Define storage
What is used to store files and programs
Define user interface
What a user will use to give commands to the device
Define command-line interface
User needs to type in command and will receive feedback on this
Define menu-driven interface
Where the interface is displayed as a list of options
Define graphical user interface
Controlled by a pointer on the screen that can select menus, windows and icons
Define voice interface
Users can give spoken commands
Define gesture interface
Typically seen on devices with a touchscreen - users can control the device by swiping or pinching fingers across screen
Define media support
Devices are able to read and write data from different types of media, e.g. SD card
Define energy consumption
The rate of power a device uses
Define software security
Used to prevent unautorised access to data
Define security
How protected your device is from potential threats
Define physical security
Method of preventing theft of a digital device
What do scanners do?
Use light sensors to record physical documents and save them as files to the computer
What is the difference between OCR and OMR?
OCR (optical character recognition) reads characters on the documents and stores the result as a text file
OMR (optical mark recognition) detects simple marks on a document - e.g. multiple choice tests
Define barcode
Pattern of lines and gaps that can be read by a device
What are the advantages of martix codes over linear barcodes
Matrix codes (QR codes) can hold much more information Can be scanned from any angle
What are the types of biometric scanners?
- Fingerprint recognition
- Facial recognition
- Voice recognition
- Iris recognition
What are the advantages of using biometric scanners?
- Easier than passwords as they cannot be forgotten
- Can speed up transactions
- Harder to confuse or trick biometric scanners
What are the disadvantages of using biometric scanners?
- Privacy and security concerns as detailed personal info is stored electronically
- Expensive to make and buy
- Can change due to injury
Define RFID (radio frequency identification) / NFC (near field communication)
Short range wireless communication method
RFID tags contain a unique ID that is linked to records in a database
Define sensor
Input peripheral that inputs data about the physical environment
State the advantages of sensors
- Can be placed in remote or dangerous places
- Can monitor continually
- Remove possiblity of human error
- Can sense things that people cannot (small changes in pressure or gas levels)
State the disadvantages of sensors
- Can be expensive to repair
- May not be able to detect if not working
- Uses higher energy consumption
Define dot matrix printer
Give one advantage and disadvantage
Print made by hitting the paper through a ribon of ink
Can make several copies at once
Very noisy
Define inkjet printer
Give one advantage and disadvantage
Use cartidges containing different coloured ink (black, cyan, magenta, yellow), tiny dots of ink sprayed onto the paper to form images or text
Better at blending colours
Slower than laser
Define laser printer
- Contain rotating cylinder or drum that holds electrical charge
- Laser used to discharge certain points on the drum to draw an image
- Electrically charged toner is attracted to those points on the drum
- Heated onto paper that is passed over the drum
Compare dot matrix, inkjet, laser printers in terms of
Speed
Slowest
Fast
Fastest
Compare dot matrix, inkjet, laser printers in terms of
Printer cost and cost per copy
Martix - cheap
Inkjet - medium
Laser - expensive
Matrix - low
Inkjet - high
Laser - medium
Compare dot matrix, inkjet, laser printers in terms of
Colour printing and quality
Rare
Yes
Yes
Low
High
Highest
Compare dot matrix, inkjet, laser printers in terms of
Examples of where it is used
When multiple copies are required
Home printing and photographs
High-colume printing in offices
How do 3D printers work?
Work by adding layers of heated material from the bottom of the mode to the top
Define plotter
Used to plot images on large sheets of paper
Moves a pen across the paper to draw lines
Used by product designers, engineers, architects
What do hard disk drives contain?
Hard disk media that is connected to the motherboard
What do solid state/ flash drives contain?
Contain flash memory media, same as HDD
What do optical disk drives contain?
Optical disk media
How do hard disks work?
These are made of circular plates called platters
A read/write head moves on an arm across the tracks on the platter
What are the types of optical media and how much storage do they hold?
CDs, DVDs and Blu-ray
CDs have the lowest storage amongst these three. Up 700MB of data can be stored.
DVDs can store about 4.7GB on one side, if it is dual-layer then 18GB.
Blu-ray use scratch protection coating. The violet laser used to store data has a greater density and therefore they can store 25GB or 50GB on a double layer.
What is the advantage of flash media?
More energy efficient than hard disks
No moving parts
Less likely to fail when moved about
Portable
What is magnetic tape used to record?
Originally used to record sound
Now used to record data
How does each media interpret the 0 or 1?
HARD DISKS – the magnetic charge of the platter changes to either negative or positive
OPTICAL MEDIA – tiny bumps on the surface represent the 0s and 1s
FLASH MEDIA – different levels of electric charges represent 0s and 1s
MAGNETIC TAPE – magnetic charge of the tape changes to either negative or positive
Name the units of storage capacity
Kilobyte - thousand
Megabyte - million
Gigabyte - billion
Terabyte - trillion
What is secondary storage used for?
Storing a document for future use
Storing an application, to be loaded into RAM when user opens the app
Virtual memory
Is secondary storage volatile or non-volatile?
Non-volatile
Define virtual memory
Space on a computer for storing instructions and programs until they are needed or being used
