Computer system

Computer system

1. Definition

   • A collection of parts that work together for a common purpose
   • It requires an input which is processed and then output
     • Can have many inputs and outputs
   • Many systems can join together and interact with eachother

2. Importance of computer systems in the modern world

   • Involved in most human activities
     • Safety
       • Airport control
       • Signaling systems
     • Travel
       • Sat nav's
       • Train timetables
       • Flight information
     • Communication
       • Phones
       • Email
       • Social media

3. Dedicated and embedded

   • Examples
     • Washing machine
     • Calculator
     • Toaster

4. Why do we need reliability

   • Security
     • Peoples data stolen
   • Safety
   • Reputation
   • Financial

5. Testing

   • Types of test
     • Valid
     • Invalid
     • Extreme
     • Alpha
       • The pogrammer testing it
     • Beta
       • The user tests it
   • Occurs throughout development and after release
     • The user reports back bugs and fixes so that the software can constantly be kept up to date

6. Standards

   • Can be used to make systems more reliable as it will adhere to certain standards. Makes it more likely to be successful and useful
   • Proprietary
     • Standards that are owned by a company
     • Windows software has to work together perfectly
     • Advantages
       • Look and feel familiar to the user which speeds up learning new systems
       • Work in a predictable way which will in turn improve reliability
       • Maintained by a single company
         • Free minor updates
   • Industry
     • Mostly hardware to allow easy interconnection between devices
     • E.g: USB (Universal Serial Bus)
   • De Facto
     • Standards that develop through common usage untill they become the accepted way
     • E.g: HTML was De Facto but is now De Jure
     • ISO
       • Internation standardisation organisation
       • Worlds largest standardising organisation
   • Open
     • Standards that are publicly available so that software developed under them can be modified by users
     • E.g: WWW, HTML, TCP/IP, C#, Linux, Android OS

7. Considerations

   • Ethical
     • What is right or wrong
     • Respecting someones privacy
   • Environmentsl
     • Energy
       • How much energy is used in the computer system
       • Cooling units
     • Disposal
       • e-waste
       • Computers are full of toxins and need to be recycled carefully
   • Legal
     • Data protection act - 1998
       • Contains personal safeguards and rules
     • Computer misuse act - 1990
       • Illegal for un authorised acces or mosifying data in computer systems