Chapter 1 - Fundamentals Of Computer Systems Flashcards
What cycle does a system carry out?
Input, process, output. (+ sometimes stores data for later use or transmitted to another computer system)
What is a system boundary?
A system is separated from the outside world by a system boundary, also called interfaces.
What are benefits of computer systems?
- improved quality in manufacturing, robotic machinery is more accurate than humans
- faster access to information
- new ways of communicating eg email SMS etc.
- cheaper manufacturing, automation reduces wage cost and allows 24/7 working
What is a general purpose system?
A personal computer designed to perform various tasks.
Various applications can be loaded so that they can be used for a wide variety of purposes.
What is a dedicated system?
Specially produced to perform a single function or set of functions.
What is an embedded system?
Computer systems which are part of a larger system , they usually also control systems.
They can be highly complex or very simple.
What is an expert system?
Computer systems designed to behave like a human expert. They have three main component parts.
What are the three main component parts of an expert system?
They have three parts:
- a knowledge base (a database of facts)
- an interface engine (software that makes deductions using the knowledge base)
- an interface (to allow a human user access to the system)
Examples of an embedded system?
Digital watches Cameras MP3 players Controllers of machinery in factories Traffic lights
Examples of uses of an expert system?
Finding faults in machinery
Choosing complex products such as mortgages and insurance policies
Suggesting products to customers
Examples of a general purpose system?
Desktop Laptop Notebooks Tablet computers Smartphones
Example of a dedicated system?
Ticket vending machine
Why is reliability important?
Because computers are central to most of our work and leisure activities and play a central part in many life or death situations (aircraft navigation, railway signalling and medical situations).
What can mistakes in design and production of systems lead to? (Making computer less reliable)
Down time
Expensive errors
Data loss
Compromised privacy
What is data integrity?
When data is accurate and consistent throughout its life. Also mean arhat the stored data reflects real world reality.
Database systems normally have rules that prevent inconsistent changes being made to the underlying data.
How can data integrity be compromised?
Human error when data is entered
Errors that occur when data is transmitted from one computer to another
Software bugs
Viruses and other malware
How can you reduce the risks to data?
Backing up data regularly
Controlling access to data via security mechanisms
Using validation rules to prevent the input of invalid data
Using error detection and correction software when transmitting data
How can you improve reliability?
Through thorough testing - testing is designed to uncover errors.
Why can testing never be complete?
Software is too complex
Testing is expensive
Testing is time consuming
What are standards?
Conventions and rules.
Why are standards important?
- They enable equipment from different manufacturers to work together
- Make learning new systems easier because they have similar characteristics
- minimise waste
- Help to ensure fair play and access to markets
- Bring costs down by opening markets to competition
What are the 5 type of standards?
De facto De jute Propriety Industry Open
What are de facto standards?
Standards which have developed over time because of common usage. They are important because they ensure that files and systems can be see by anyone.
Examples of a de facto standards?
The QWERTY keyboard
Microsoft word
What are de jure standards?
Standards that have become so universally accepted that they have to be adhered to or communication is impossible.
Examples of de jure standards?
ASCII
PDF
Unicode
What are propriety standards?
propriety standards are owned by organisations. They ensure compatibility between the company’s product.
What are industry standards?
Set by recognised non commercial organisations
Examples of industry standards?
ANSI which sets standards for some programming languages
ITU sets standards for communication protocols
IEEE sets standards for electrical interfaces
Characteristics of open standards?
Publicly available
Produced collaboratively
Not dominated by one interest group
Not for profit
What do open standards ensure?
That access to resources is not dependent upon a single application or particular hardware
Examples of open standards?
HTTP
HTML
SQL
WAP
Examples of ethical and legal issues involving computer use?
Privacy Data security Espionage Copyright Terrorism Cyber crime
What is a computer system?
A collection o hardware and software that works together to achieve some data processing tasks.
How does the government protect the privacy of individuals?
They put in place laws such as the UK Data Protection Act
Why are legislations needed to protect individuals privacy?
Because it is easy to copy, transmit, match data and make judgement on people from data
What are environmental advantages associated to computer use?
Less paper used
Manufactured goods are maxed to a greyer degree of precision, am king them more efficient
Environmental disadvantages associated to computer use?
observer computers have to be disposed of, however they contain toxic materials (lead, cadmium, beryllium, flame retardants)
Plastic of computer is burned to extract valuable metals however this releases dangerous chemicals
Uses lots of energy - fossil fuels
Where is computer waste shipped to?
E-waste is shipped to developing countries where there are few safeguards and standards are poorer
Most e waste goes to landfill, chemicals leach into soil
How is the amount of energy used by computers reduced?
Solid state storage uses less energy than roaring disk drives
Automatic stand by turns of computer when they are not in use
Laying out equipment so that it can be cooled efficiently
Modern screens are less energy intensive
Virtual servers reduce the number of physical servers in a data center
Why do computers use so much energy?
Energy used to run sir conditioning to cool computers
