Computing A451

A Computer System is any device that can take inputs, process them and produce a set of outputs. These are alll carried out by the CPU. This is a fetch execute cycle.

For the computer to be able to process data there must be a set of instructions in place, this is your programme.

Three devices that are computer systems:

• Central Heating
• Tablet
• Laptop

A laptop is a computer system as you press a key (input), the computer turns it into an instruction which is then decoded. The ouput is the result shown on the monitor.

Computer Systems are all around us. They entertain us, help us to keep in touch, keep us safe and help us to complete work.

Home Computer Systems:

• At home there are lots of Computer Systems
• Burglar Alarm, Microwave, Central Heating, TV Box, Smart Phone
• All of these systems have been developed and programmed to do their job
  

Computers in the work place:

• Need access to printers, servers and different networks.
• They allow us to collaberate documents
• Video Conference

Person Failures:

• Loss of photos
• Loss of software
• Loss of documents

Business Failures:

• Loss of Customer Records
• High costs to repair
• Security Threats

Hardware Redundancy:

• Parts are duplicated 
• When one fails other will step in
• e.g Power Supply

Software Redundancy:

• Duplicate Software
• Important in medicine equiptment and transport

Data Redundancy:

• Duplication on another device
• Data is not lost
• Broken storage device is easily replaced

Ways to back up data:

• USB
• Cloud
• Hard-Drives

Hardware Redundancy:

• Parts are duplicated 
• When one fails other will step in

Software Redundancy:

• Duplicate Software
• Important in medicine equiptment and transport

Data Redundancy:

• Duplication on another device
• Broken storage device is easily replaced

Ways to back up data:

• USB
• Cloud
• Hard-Drives

Methods of Creating Software:

Waterfall:

• Define, Analyse, Design, Implement, Test, Installation, Maintenence

Prototyping:

• Needs, Part of Code, Customer test, feedback, code improved, CONTINUOUS

RAD (Rapid Application Development)

• Similar to prototyping
• Includes tools to rapidly change programmes.
• GUI - Graphical User Interface
• CASE - Computer Aided Software Equiptment
• EXPENSIVE

Computer Misuse Act:

• This is to stop people using computers to steal, delete, modify or gain unauthorised access to data.

Copyright, Designs and Patent Act:

• Anything that someone has created is called INTELLECTUAL PROPERTY. This stops people using the material without consent.

Data Protection Act 1998:

• A mass amount of data is held on computer systems.
• To protect this data all companies must follow the data protection act.
• It has eight principles

Enviromental:

• Recycling - ensuring that organisations such as schools or hospitals recycle rather than dispose.
• Energy - computers can save energy to help protect the enviroment. (Virtual Servers)

Ethical:

• Privacy - who keeps what and for how long
• Responsibility - being honourable and trusted engineer
• Disabilty - does the system cater to everyones needs
• Politics - freedom of information and how it is used