Chapter 1: Fundamentals of Computer Systems Flashcards
What is a computer system made up of?
Hardware and software
What is hardware?
Any physical component that makes up the computer
What is software?
Any program that runs on the computer
What are some examples of computer systems?
- PCs
- mobile phones
- cash machines
- supermarket tills
- engine management systems in a modern-day car
What is the basic model of any computer system?
Input–> CPU(processing)–> Output
What must all computer systems have?
At least one input device that gets data from the real world
What are some examples of input devices that get data from the real world?
- mouse
- keyboard
- temperature sensor(thermistor)
- microphone
What do input devices do with real-world data?
They convert it into a form that can be stored by the computer
What are some examples of an output device?
- a computer screen
- an actuator that opens or closes things
- speakers
What are the four components of any computer system?
- input device
- CPU
- output device
- storage
What does CPU stand for?
Central Processing Unit
What is the basic model showing the collection of input?
Real-world action–> analogue-to-digital conversion–> binary data to computer
What is the basic model showing the production of output?
Binary data from computer–> digital-to-analogue conversion–> real-world effect
Why are computers important within the modern world?
Because people are increasingly dependent on them at school,work and home
What are some ways people are dependent on computer systems?
- they are imbedded in household appliances
- mobile phones, TVs and games consoles are computer systems
- they control the engine, GPS, windows and stereo of a car
Why is the reliability of computer systems extremely important?
- if computer-controlled signage on motorways goes wrong there could be health and safety implications
- if computer systems in hospitals go wrong people could die
In certain situations, what two features can reliability sometimes be more important than?
- how quickly they work
- how many features they have
Who do you measure how reliable a computer is?
- system availability
- MTBF
What does MTBF stand for?
Mean Time Between Failure
What is system availability?
The percentage of time a system is available for
If a system is down for 1 hour in a 100 hour period, what is its system availability ?
99%
How does MTBF measure system availability?
It measures the length of time between system failures
What are two features it is important for computer systems to have?
- reliability
- robustness
What does robustness mean in terms of computer systems?
How tolerant the system is to failure
What can a robust system be described as?
Fault-tolerant
What will happen when a single failure happens in a system that isn’t robust?
It will take the whole system down
What is a way of protecting systems?
Hardware redundancy
What is hardware redundancy?
Having more than one of each critical component
What is usually at greatest risk when hardware or software problems occur?
Data
How should companies protect against system failures?
- hardware redundancy
- backing up data regularly
What needs to happen when a company dependent on computer systems experiences its failure?
Disaster recovery plans
What happens during disaster recovery plans?
A company switches over all it’s own data to a completely new system
How much time do disaster recovery plans usually have?
Hours
What are the three types of issues related to the use of computer technology in society?
Legal, ethical and environmental
What is the Data Protection Act?
A legal requirement stating that anyone who stores personal details must keep them secure
What must companies who store any personal data do in order to comply with the Data Protection Act?
Have processes and security mechanisms designed in the system to keep information secure
Why was the Data Protection Act created?
To protect individuals’ data
What are the three most widely known laws relating to computer systems?
- the Data Protection Act
- the Health and Safety at Work Act
- the Copyright, Designs and Patents Act
What areas does computer technology have an impact on society?
- communication
- employment
- social interaction
- shopping
- manufacturing
- safety
What is the positive effect of computer technology on safety?
Many dangerous jobs can now be done by remote controlled devices
What are the positive effects of computer technology on manufacturing?
- produces items more cheaply
- produced quicker and more precisely than if done by hand
What is the advantage of computer technology in the area of shopping?
Provides online shopping which can help people who can’t get to shops
What are the disadvantages of computer technology in the area of shopping?
- CD and DVD sales have dropped
- increase in credit card fraud and identity theft
