Unit 1-Digital devices Flashcards
A supercomputer is essentially a stronger….
Mainframe computer
Mainframe is for _____ data processing
Bulk
Super computers are used for…..
Calculations
Micorprocessors are the…
‘engine’ of the computer
peripheral devices are…
connected externally or on outside or edge of computer.
Who sends request? Client computer or server computer?
Client computer, server computer sends the data/service. For e.g: Google web page, our computer and typing is client and server fetches data.
Servers are used to….
Provide data unlike supercomputers or mainfframes that manage the data and utilize it.
Super computers do _______ of______s per second
- trillions
2.calculations
Super computers can be used for ……
Nuclear research
upgrades are added to make something…
easier and better for use.
Use of personal computer
To generally carry out many tasks, such as:
-carry otu tasks
- Play games
- Browsing world wide web
- Designa nd build web pages
-Accessing internet.
-etc.
What does ‘www’ stand for
world wide web
When was desktop computer come to being?
1980
What was the purpose of Desktop computers
Small enough to fit on a desk, cheap enough for everyone to have their own PC, and so everyone wouldnt have to share a mainframe.
Typical destop computer shared the same components as….
A mainframe computer, for a fraction of the cost
What components does a mainframe computer share with a desktop computer?
CPU, RAM, storage, etc.
Laptops have a ___ monitor
LCD
____ use a tracker pad and wireless connections rather than a mouse and network/printer
Laptop
Pros of a laptop
-rechargable battery
-portable.
Name some digital devices
-PC’s
-desktop
-mainframe coputer
-supercomputer
-server
-lapotp
What does ‘CPU’ stand for?
Central Processing Unit
Name 3 main parts of a CPU
- ALU= arithmetical/logical unit
- CU= Control unit.
- Memory/storage Unit
Memory is typically measured in…
Bytes
Define volatile
Memory that needs power to preserve data
Is a hard drive volatile?
no-it can store memory without a power source
Is the RAM volatile
Yes! It needs a power source to back-up data
CPU parts
In the memory storage unit, its used for temporarily storing data while the computer is on
RAM-since its volatile
Where can a hybrid computer be used?
A hospital, real-time modeling.
and a gas pump.
define analog computer
Use physical surrounding and signals to perform calculation. Suited for complex real-time simulations.
Define digital computer
Use binary to provide high accuracy.
What a key difference between anolog and digital computer?
Digital uses 0’s and 1’s to perfom calculations and logical math problems while analog uses signals and models to solve physical and mathematical calculations/problems
What are tablets mostly designed/used for?
Consuming media, web browsing.
What does SIM stand for?
‘Subscriber Identity Module’
What does Wi-Fi stand for?
Wireless fidelity
Wireless fidelity allows devices to connect to the ____ using ______ _____ instead of wires
1.internet
2.Radio signals
The SIM (_____ ______ ____) lets the ____ network know who you are and with the phone/network provider,(Du, etisalat)
- subscriber identity module
- phone
Define ‘mobile network’
Allows for connection and services in SIM card.
Microchip and processor
if a microship has more than one processsor, what do we call-
-the chip?
-the processors?
1.the chip is now refferred to as a processore
2.the processors are now called ‘cores’
define a hardware
Physical device
Define input and an example
The information or data we provide/givent o device, e.g: asking the computer a question
Defien output and an example
result or information genereated in response/we recieve, e.g: answer from google
3 types of peripheral devices
- Input
- Output
- Storage
input devices
What does OMR stand for and what does it do?
Optical mark reader-can mark papers
What is OCR and what does it do?
Optical character recognition- A scanner that allows recognition of text and saves it as a text file/pdf.
Input devices
QR codes are also known as
Matrix Codes
2 types of barcodes
- Linear
- matrix
3 types of perpheral devices?
- Input
- Output
- Storage
Name the 4 biometric scanners
- Iris(120x more reliable than finger scan)
- Finger
- Facial structure
- Voice print
Input devices
3 card types
- Magnetic strip
- Radio frequemcy identification and Near field communication
- Programmable chip
RFID and NFC (definition and purpose)
Near field communication is essentially a brand if not part of Radio Frequency Identification, RFID are short-range wireless communication basically a tag in keys and cards that stores data into data base.
Input devices
Programmable chip
A chip in credit cards that reduced fraud by 67% in the UK in 2005. As it requires a PIN
Magnetic strip(Cards)
Least secure, the strip stores data and is to be swiped, can be swiped without owners knowledge.
Manual and direct input differences.
Manual: input by human. e.g: keyboard
Direct: input by computer. e.g: Scanner
Advantages of biometric scanners
(name 2 atleast)
- Cannot be forgotten like passwords can.
- dont rrequire langauage(no language barrier)
- Cannot be manipulated easily
- Fast and efficient in transactions.
Disadvantages of biometric scanners
(name atleast 2)
- People can be uncomfortable
- Concern of personal data stored electronically
- can POSSIBLY be stolen
- Expensive to make and buy
2 types of touch screen
Resistive touch and how it works
More durable than capacitive, touch measured by pressure of 2 layers once the top one has applied force however the thickness cuts the clarity of the screen. also cannot withstand multiple touches.
2 types of touch screen
Capacitive touch and how it works
Touch sensed by electrical conductivity and can give high clarity.
Define resolution
Number of pixels in an image
What is the SIM’s purpose in terms of ‘staying online’ ?
The SIM provides the mobile network your identity so you can sstay online with no WiFi signals.(does NOT provide WiFi, provides mobile network [mobile data] )
3 factors affecting performance of a device.
- Hardware( RAM, CPU)
- Software(optimization and upgradees)
- Workload given
What is an SBC and what is it used for?
(also provide name of 2 types)
A single board computer used for educationa and is affordable, has 2 types-
1. physical computing-
2. Embedded computing
What are uses of Physical embedding SBC?
Can carry out physical programs(connect to physical world and collect data) in a robot if embedded via sensors
in ‘()’ is an accurate exam answer.
Embedded SBC function
Carry out specific functions.
5 user interfaces
- Graphical
- Menu driven
- Voice
- Command line
- Gesture
Define interface
Essentially a bridge between programs and softwafare of a computer, helps them work together effectively.
Graphical interface has — parts. These are known as —-,—-,and —-. Main purpose of the interface is to —
- 3;
- Windows(for apps and software)
- Icons(graphical images of apps)
- Menu(for operating system)
- visual for user
Voice interface allows for …..
Voice spoken commands
Define menu-driven interface and and exmaple.
- Helps a user interact with the software itself.
- Smartphone- helps you naviagte through apps.
Command line interface and example.
- Unlike menu driven, we use text to inetract with the software like coding and commands.
- An example is the text based prompts in windows you can use to alter system configurtaion.
Gesture interface and example
Use body or hand to interact with software like a joystick, it will interact with the sprite when you interact with the joystick with your hands.
(though a joysitck is a device it still helps bridge between software and helps us work effectively so can be considred an interface)
What is a sensor?
collect data on physical surroundings via input w/- need of human touch.
Why do washing machines have sensors?
Measure the temeperature of water, if it’s too hot the actuator tells the machine to fill with cooler water, if it’s too cold the actuator informs the computer to make it warmer.
A common use of pressure sensor
Burglary-under the doormart to detect pressure.
5 types of output display
- Electronic display
- Audio
- Video
- Tactile(touch) form
- Printed text
What is the slowest type of printer
Dot matrix
Dot matrix characteristics
- slowest
- loudest
- poor quality
- ‘impact printer’ as a ribbon of ink hits the paper -
- carbon layers of paper so many copies can be made.
- Used in pharmacies
2 common printers
- inkjet
- laser printer
The most efficient printer in work places and why
Laser printer - fast, not noisy, pay for expenses once and then only cheap ink is needed to be refilled.
How does a laser printer work?
A laser draws the image on a drum and then toner(powder ink for printer) is sprinkled on the drum, only sticking to the lasered area. The drum rolls over the paper producing a nice high-quality print.
Which printer is for bulk printing?
Laser printer
3 colour cartidges in inkjet printer
- cyan
- yellow
- magenta
name….
1. A printer most likely in your home
2. A printer for work spaces
3. a printer for airplane parts, recently developed a way to turn stem cells into organs
4. A printer for printing large billboards, and uses a pen across the large paper
5. Used for pharmacy reciepts
- Inkjet
- laser
- 3D printer
- Plotter
- Dot matrix
Define mono sound and stereo sound
Mono sound: single channel on all speakers, e.g: speech in auditorium, more clear
Stereo sound: 2 or more channels on each speaker, e.g: theatre, more detailed
Define “surround sound”
sound from all 4 directions at viewer for realism
Amount of —– on screen is the resolution, to find this we multiply the — by the —
- pixels
- Length
- Width
What is the only input **and **output device?
Touch screen
Components/characteristics of a data projector
- Portability
- Light bulbs: luminous and brightness
- Like monitors, have resolution
- Zoom functionalities:
-Digital zoom: enlarges a part of image creating an effect of zoom
-Optical zoom: zooming with lens
What is a control device
Make something change in the physical world(often mechanical) . The actuator is what does this.
Step by step on how the control device makes a change.
- A sensor gathers data
- Data is processed
- Data sent to control device
- Control device physically changes something
- Actuators are the part that physically change it.
Where is 3D printing used?
- hospitals
- houses
- airplanes
A mobile device is just —— computer, although a mobile device with ——–s is considered a smartphone.
1.smaller
2.application
A tablet is essentially a —– screen computer made for —– and —–.
1.touch
2.browsing
3.media
2 primary storages
RAm and ROM
Benefits/Uses of secondary storage
- non-volatile: will save data if computer looses power.
- Used for storing documents
- For storing applications for when user needs it, will open via RAM(primary storage)
- Virtual memory: exists in primary storage- stores OS’s, code, instructions and programs on computer, used in secondary only going to primary/main when needed.
Storage media —– data while storage device —— it.
- stores
- accesses
What do storage peripheral devices do?
Store data or software components
Can storage devices also be internal? How?
yes- these internal storage devices connecting, exists in the motherboard(circuit connecting to other components).
2 Data access types
- Serial access data
- Direct access data
Which data access type is faster
Direct access
Describe the process and give a characteristic of serial accessing of data
Scrolling through base of file and every record to find specific file.
- Very slow
Where is serial accessing of data used/required?
Name 5 atleast
- Clearing cheques
- Utility bills
- Library checkouts
- Student attendance
- Parking tickets
- Super market reciepts
- Producing slips
- Medical records
What is direct accessing of data?
Typing in a key field to find file. E.g: ctrl+F to find a file in folder.
Where is direct accessing of data used?
Storage devices using serial accessing?
Magnetic tape drives and RFID systems
Storage devices using direct accessing?
HDD’s and SDD’s
Why do we back-up data?
- To protect original if sending a file
- Incase is lost
- Incase data is damaged
Magnetic backing stoorage, how does it work(briefly)?
Magnetically holds data by magnetizing surface charges: positiv or negative charges based on 0 or 1
Magnetic tape drive uses
When lots of storage is needed, but not where speed is needed, the slowest at transferring. But for bulk data processing
Magnetic tape drive advantages and disadvantages
list 2 of each.
Advantages:
- less expensive than HDD’s
- Large storage capacity
- Durable
Disadvantages:
- Use serial access
- Another tape is required to update data
- Affected by magnetic field
Hard disk drives(fixed) can store….
- OS(can be installed into HDD
- Software systems: device drives like ports and instructions to handle and produce data via software.
- Web data is also installed on HDD sometimes
- File servers
Advantages and disadvantages of HDD’s(fixed)
Advantages:
- Fast access to data
- Large memory capacity
- * Lower cost per gigabite*
Disadvantages:
- Not durable
- Not portable
- Easily damaged: Has lots of moving parts that can be damaged or damage data.
HDD’s (portable) can be used for….
Any 3 uses
- Back up data
- Transfer files
- Gaming
- Digital library
- Archiving files
Advantages and disadvantages of fixed HDD’s
Advantages:
- Data access time is fast
- transfer rate is fast
- Large memory
- Can be used between computers
Disadvantages:
- Easily damaged if dropped or incorrectly shut down
- Not as much storage as fixed HDD
- If walking and magnetic field inteferes with device, all data is at risk of corruption.
How does optical backing storage media work?
A laser burns dots and bumps into a disk differentiating between two patterns for 1 or 0
CD-R/DVD-R uses
List any 3
- Store films
- Data for transfer
- Software distrubution
- Software backup
- media storage
- Legal and business docs
CD-R/DVD-R advantages and disadvantages.
3 of each
Advantages:
- Cheaper than RW disks
- Once finalized, behave like ROM
- Portable
- Reliable and durable
- Compatibility(universally)
Disadvantages:
- Can only be recorder once; if editing needed another purchase must be made
- Must be thrown away if error
- Some CD/DVD players can’t read C-R and DVD-R
- Prone to scratches
- though has a large storage, risks limited storage as you can only archive and finalize once.
CD-RW/DVD-RW uses
atleast 3
- Record CCTV
- Television programs to be rewatched(Multisession recording)
- Software testing
- Backing up-data
- Mixtapes and playlists
.
CD-RW/DVD-RW advantages and disadvantages
Advantages:
- Can be re-written many times
- Can use different file formats
- Not as wasteful as R
- Can be re-used
- Multisession recording
Disadvantages:
- Limited capacity
- Slower writing rate
- Fragile
- May not be “backward compatible” sometimes.\
- Costly sometimes
Blu-ray disk v.s DVD
3 points
- Blu-ray uses blue laser(not red) with a shorter wavelength allowing for tinier bumps to be lasered allowing more storage.(5x more)
- Blu-ray automatically incripts data to prevent copyright and piracy
- Transfer rates:
- Bluray: 36 Mbps
- DVD: 10 Mbps(megabits per second)
Blu-ray disk uses
- Movies
- Games
- High access speed rate
- Large storage
- Educational content
- Interactive media
Advantages and disadvantages of Blu-ray disks
Advantages:
- Large storage capacity
- Scratch proof
- Automatically encrypts data
- Acces speed is faster than other optical devices
- High definition/quality
Disadvantages:
- Expensive
- encryption problems
- DVD’s have HD quality
- though more storage, limited for large files
- Fragile.
How does a SSD work?
A solid state drive stores data without moving parts but rather in cells.
SSD uses
- Store files
- Store OS
- Tranfer files with ease
- transfer codes easily
- easiest form of transfer.
- Applications
- Games
- Research and computing(for quick analysis.)
SSD(E.g: pen drive) advantages and disadvantages
Advantages:
- Compact - doesn’t require additional software to operate
- Very fast( can simply copy and paste)
- Very durable and backwards compatible
- Very reliable as no risk of moving parts
- Silent operation
Disadvantages:
- Easy to loose
- Can’t archive/”read-only” data.
- Incorrect removal can remove everything
- Can still wear out over time via multiple re-writes
- Some may be effected when neaaring full capacity of storage.
How much data can a CD store? (in Mb)
700 Mb
Storage of…
- Single sided DVD
- Dual sided DVD
- 4.7 GB
- 18 GB
What does CD stand for?
Compact disk
What does DVD stand for?
Digital video disk
Define backwards compatibility
Older computer software or hardware being able to be used with newer hardware/software, without special adaptations.
Define seek time, which device it’s directed and which part as well as the speed.
The time for the read/write hand to move over the disk essentially reading the disk. Directed at hard disk drive and it’s read/write hand. The average time/usual time is 4-15 milliseconds.
what is the spot size of the laser used for CD’s, DVD’s, and Blu-ray disks?
- CD : 1.6-2.11µm
- DVD : 0.8-1.3 µm
- Blu-ray disk : 0.35-0.58 µm
Order these from highest to lowest
- Magnetic tape
- HDD
- Flash media
- Optical media
Order these from highest to lowest in terms of speed(data access rate):
- Magnetic tape
- HDD
- Flash media
- Optical media
- Flash media
- HDD
- Optical media
- Magnetic tape.
Order these from highest to lowest in terms of storage:
- Magnetic tape
- HDD
- Flash media
- Optical media
- Magnetic tape
- HDD
- Optical media
- Flash media
How is data stored?(in what format)
hint: —- form
Binary- 1 and 0’s
Order these from highest to lowest in terms of cost:
- Magnetic tape
- HDD
- Flash media
- Optical media
- Flash media
- HDD
- Optical media
- Magnetic Tape
How many bytes is a mega-byte?
1,000,000
How many bytes in a GB?
1,000,000,000
What is a TB?
A terabyte is 1,000,000,000,000 bytes.
How does a HDD store Binary
Changing the magnetic field on the platter to positive or negative for 1 or 0.
How does Flash media store binary?
Cells coded for 1 or 0
Purpose of system software?
Maintain or operate computer system
2 primary memories
- RAM
- ROM
2 secondary memories
- Pen drive
- HDD
What are 2 types of softwares and the key difference between them?
- Application software: we use it
- System software: helps run hardware so computer can run
What is software?
A program that runs on your computer
Utility software is a form of —- software, it carries out —- and —- taks
- System
- Configuration
- Maintanence
4 uses of utility software
- Re-arranging (de fragmentation)
- Opening/running programs
- Ordering files
- Backup data
A key difference between utility software and application software?
Utility software runs programs like hardware and OS, however WE run application i.e application software is user specific, utility software isn’t.
An ability of utility software that can be automatic or user specifically started in a computer?
De-fragmentation
What is a specialist phone?
A phone fit for users specific needs: for example a phone may have emergency contacts, the phone will call every one in order until one picks up.
The alto 2 is a kind of…… phone, it helps —- people by —- the name of contacts out loud. Nicknamed the “— —”
- Specialist
- blind
- Saying
- Talking phone
