Fundamentals of a Computer System

Fundamentals of a Computer System

1. Computer system = one that is able to take a set of inputs, process them and create a set of outputs. It may be able to store information and/or communicate with other systems

   • a computer system can : receive, store, process and output data
   • the computer systems consists of: input devices, output devices, internal memory, processing devices, storage devices and software which provides instructions to the processing devices.
   • safety critical or life critical systems: failure of computer systems can result in serious damage or death

2. Importance is to : to keep us safe, to enable us to do our jobs, to entertain us, to run our homes, to enable to communicate with other people.

3. reliability = the probability that a computer will produce the correct output

   • have a clear design that satisfies user requirements
   • designed with safety and possible failure in mind
   • design must make testing easy and include test plans
   • design must be developed according to defined standards
   • testing should be carried out throughout development
   • maintenance should be carried out after the system goes live
   • systems can have failsafe mechanisms built in
   • system must be design and created to defined standards

4. Legal aspects when making computer system:

   • sharing and distributing films and other media: illegal to rip a copyright DVD and distribute online, P2P makes it easy for people to share online with file sharing networks and hosting websites
   • hacking: and activity which makes unusual use of, or attempts to break, a computer system.
     • can be used to look for weaknesses in systems to access and steal private data
     • creatively explore new ways of using a program or computer
     • working around bugs in code
     • exposing security risks in software and websites, warning the general public
     • testing the security of a program
     • a 'hack day'- where people get together to explore new technologies
   • data protection act sets out principles that govern:
     • who can access data
     • the accuracy and validity of data
     • selling data
     • removal of data
     • breaching the data protection act can lead to prison or heavy fines
   • sharing data online
     • when signing up for social media sites we are creating a record of our interests
     • when signing up we are agreeing to share a certain amount of personal data with the privder
     • this data can help marketing companies to target the right market of people
   • proxy servers
     • IP adresses can be masked using a proxy server
     • criminal gangs set them up to entice people to download software with viruses
     • businesses can mask their internal company work by using a proxy server
   • computer misuse act makes it an offence to:
     • access computer material without permission
     • access computer material without permission with the intent to commit a criminal offence
     • alter computer data without permission. eg writing a virus

5. computers and the environment

   • advantages
     • using email and working electronically means less printing is required
     • using FaceTime and Skype and video conferences means people don't need to travel to meet each other, less fuel is used
     • people can work from home- which reduces commuting
   • disadvantages
     • technology consumes energy with electricity
     • creating technological waste which can contain poisonous chemicals

6. Patents

   • to register ownership of an invention or new process and be given a patent
   • can stop people from copying the idea for a set number of years

7. copyright

   • gives the creators of media the rights to control how media is used and distributed
   • music, books, video and software can all be copyrighted