computer system Flashcards
bruh
What is ‘hardware’?
all of the physical components of a computer system
Examples of internal hardware
internal:
RAM
ROM
processor
video cards
What is ‘software’?
coded programs that control how the computer works
Examples of applications software
disk cleaners
virus protection
word processors
Motherboard
Circuit board that allows CPU, RAM and other hardware components to communicate with each other
All components plug into the motherboard
ROM (Internal memory)
Secondary storage
* ROM: read only memory
* Used to store permanent information
* Chips cannot be altered, only read from
* Nonvolatile memory: data not lost when computer turned off
used to store computer’s configuration data, such as BIOS.
Processor (CPU)
Brain of the computer
Controls what computer does + is responsible for performing calculations and data processing
recieves and decodes instructions and carries them out
RAM (Internal memory)
- ‘Primary Storage’
- RAM: random access memory
- All programs and data in current use is stored on RAM
- Volatile memory: data lost when computer turned off
Video card / graphics card
Plug into motherboard, enables computer to display images on monitor
Sound card
Plug into motherboard – allow computer system to produce sound + connect microphones
Storage devices (secondary backing storage) definition
Stores data that is not instantly used by the computer
What is an ‘operating system’?
a software program that manages computer resources.
Operating systems allow components to communicate with each other and enables the computer to run software applications.
Command Line Interface (CLI)
Older style operating system → users type in commands using keyboard.
Do not make use of images, icons or graphics. All the user is seen is a plain black screen
Advantages of CLI
ads:
If user knows correct commands then can be faster than any other type of interface
Uses less RAM
Does not use as much CPU processing time
Cheaper monitor can be used
Graphical User Interface (GUI)
makes use of pictures, graphics and icons
Uses WIMP (windows icons menu and pointing device)
Advantages of GUI
ads:
Easy to use for beginners (intuitive)
Don’t have to learn complicated commands
Advantages of PC
They are easier and less costly to upgrade and expand.
No critical power consumption because they plug into a wall socket.
Due to fixed positions, they are less likely to be damaged or stolen.
As they usually have wired connections, they have more stable internet access.
Laptop
Portable computers that fit on your laps.
Can be used almost anywhere due to small size and built-in batteries.
Powerful as PCs and can perform similar tasks.
Advantages of laptops
ads:
Smaller and lighter than PCs. portable Components are low-power Built-in rechargeable battery means they can work without a constant power supply Come with built-in Wi-Fi. No need to transfer files as can take your laptop with you.
External hardware example
keyboard
mouse
monitor
speakers
webcam
scanner
System software example
operating system
linkers
compiler
device driver
Disadvantages of CLI
disads:
Can be confusing for new users
Commands have to be typed precisely
If mistype an instruction, start from scratch
Large number of commands to be learned
Disadvantages of GUI
disads:
Take up larger amount of hard disk space
Need significantly more RAM to run
More processing power than other interfaces
Slow for experienced programmers
Disadvantage of PC
disads:
Large and bulky. not portable Constant power supply / do not use batteries. Need to copy files onto portable storage or send via email if work in a different location.
Disadvantage of laptop
disads:
portability makes it easier for them to be stolen. limited battery life means the user needs to carry a charger at all times. keyboards and pointing devices may be awkward to use. not easy to upgrade, like adding more RAM.
digital data
high bandwidth
discrete
binary ( 0,1s)
can be processed without conversion
Uses sampling to capture data
analogue data
continuous
waveform
low bandwidth ( less data transfer)
needs to be converted to be processed by computer
application software defintion
Provides services that allow the user to do specific tasks.
It can be general-purpose software or custom-made software. (Specialist software)
E.g., Spreadsheets, databases, and word processors.
system software definition
provide a platform all other software can run
controls hardware + software
provides link between hardware and user
provides the services required for the computer to operate
cpu
understands and executes hardware and software operations.
consists of a control unit (CU) that manages the input and output devices, an arithmetic and logic unit (ALU) that performs computations and makes logical judgments, and tiny memory regions known as registers.
phone advantage
Advantages:
very small in size and lightweight, makes them portable.
wifi makes them portable too
they can be used almost anywhere.
they have apps which can tell instant location
they have reasonable battery life.
phone disadvantage
small screens and keyboards make pages difficult to read.
more difficult and slower when typing things in
Memory size in most phones is not very large when compared to laptops and desktops.
Not all website features are compatible with smartphone operating systems.
easy to lose
use of phone / tablet
They allow users to send/receive emails.
They allow users to use a number of apps.
They allow users to use a camera feature (to take photos or videos).
They allow users to use an MP3/4 player (for music and videos).
advantage of tablet vs laptop
( found this on znotes its kinda goofy)
fully portable
touch screen technology means they are simple to use and don’t need any other input devices.
The battery life of a tablet is a lot longer.
when the power button is pressed, it goes into standby but remains connected to the internet so the user still hears alerts when emails or other ‘events’ are received.
disadvantage of tablet vs laptop
( found this on znotes its kinda goofy)
tend to be rather expensive when compared to laptops.
they often have limited memory/storage when compared to a laptop.
typing on a touch screen can be slow and error-prone compared to a standard keyboard.
AI artifical intelligence
AI is a machine or application which carries out a task that requires some degree of intelligence.
ai use
recognizing a person’s face, the ability to operate machinery, such as a car, analyzing data to predict the outcome of a future event, such as weather forecasting. Impact:
Everyday uses:
An autonomous (driverless) vehicle – Robotic research help amputees and people with disabilities. Robots are used to help people carry out dangerous or unpleasant tasks – for example, bomb disposal.
negative of ai
Unemployment, robots are capable of doing tedious human tasks with much more efficiency and excellence than humans.
Dependency on technology could lead to problems in the future.
De-skilling: Talents are now done on a regular basis by machines.
Augmented reality (AR) is
lays objects onto pre-existing objects. e.g., Pokémon GO!
Uses:
gaming
healthcare
Inversive education
layering filters in social media
Virtual reality (VR)
enables an entirely new world to be created, no link to the actual surroundings of the user.
It requires the user to be specially equipped with a VR headset, joystick, and headphones.
Impact: Military applications, educational purposes (looking at ancient buildings), healthcare, media (interactive special effects in a movie), scientific visualization (part of molecular structures/cells).
Dialogue-based user interface:
use the human voice to give commands to a computer system.
useful for people with disabilities
unreliable, with many commands not being recognized or needing to be repeated several times (especially if there is background noise).
Can be quite complex to setup. User needs to know which commands can be used.
Gesture-based user interface:
relies on human interaction by the moving of hands, head or even feet.
Very natural interface for a human operator. No training is needed to interface with the computer.
It is possible for unintentional movement to be picked up.
Only works near the camera or sensor (maximum of 1.5 meters).
May only accept a limited number of movements (for example, it may take several attempts to determine exactly what finger movements are recognized).
can get tired
