GCSE Computing: Fundamentals of Computer Systems

GCSE Computing: Fundamentals of Computer SystemsContentsKeywordsComputer Systems The importance of computer systems in the modern world Reliability of Computer Systems Factors that concern making computer systems Ethics Environmental Legalities Dedicated vs. General Purpose StandardsStandards Proprietary Standards Industry Standards De Facto Standards Open Standards Summary__________________________________________KeywordsDedicated: Meaning a computer system has a fixed purpose.Embedded System: A computer system that forms part of an electronic device.Kernel: The lowest level of an operating system that controls hardware.HTML: HyperText Markup Language - a language based system for defining web pages.PDF: Portable Document Format - a file standard that displays a document accurately on any computer platform.ISO: International Organisation for Standardisation - the world's largest standards development organisation that produces international standards for engineering, agriculture, medicine and information for technology.TCP/IP: Transmission Control Protocol/Internet Protocol - a set of standards that control how data is sent across network, including the internet.De facto standard: Something that is used s widely that it is considered a standard for a given application, despite having no official status.Proprietary standards: Specifications for hardware or software that are controlled by one company.Open standards: Anybody can use this, to a point where anyone can modify it.Industry standards: Generally accepted requirements followed by the members of an industry.__________________________________________Computer Systems A computer system is interconnected computers that share a central storage system and various peripheral devices such as printers, scanners or routers. Each computer can operate independently, but has the ability to communicate with external devices and computers. The importance of computer systems in the modern worldNavigation: GPS, smart phone applicationsSafety: guiding aircraft, supporting signal systems, monitoring a patients body signsBusiness and Retail: stock controlEntertainment: DVD's, Blu Ray, MP3 playersCommunication: exam marking, unlimited sources of information on the internetPolitics and Government: campaigns, payment of taxesReliability of computer systemsThe reliability on computer systems is huge. Many things can go wrong: hardware failures, for example, the hardware stops working; softwares itself may contain bugs and errors; human error; malicious, deliberate damage to a system; natural disasters, for example, fires, power cuts, flooring or earthquakes.If any disruption is caused to critical systems like banking, emergency services etc, it could wreak immense havoc. Critical systems can be targeted by cyber terrorism.Methods of saving data include backing up information (full backup and incremental backup); UPS's (Uninterruptible Power Supply) or generators for disaster recovery; redundancy (extra or duplicate resources) and parallel setups; fault-tolerant design so that the system can 'fail gracefully'. This could include emergency copies of data. Defensive programming is also available, allowing the software to cope better with added checks in the code to ensure the programme works correctly. Factors that Concern Making Computer SystemsEthicsThe only ethical concern about creating computer systems is that it is reducing employment. Automated production lines for example, reduce the need for workers. Environmental Energy: Modern computer systems consume less power with new, improved monitors and sleep modes, however, it is still more energy than the aviation industry. Energy supplies are finite and expensive. They need to economically and reliably stable as we depend on it. Disposal: Computers contain toxic and carcinogenic components called dioxins. Most are sent to landfill site where toxins spread to the environments - this is a major issue. LegalitiesThe Data Protection Act 1998: this includes keeping data no longer than necessary, keeping it safe, and keeping the data accurate and up to date.The Computer Misuse Act 1990: this involves trying to access data or programs which are unauthorized, trying to access other computers to commit crime and the unauthorized changing of data. The Copyright, Design and Patents Act 1998: this prevents people from copying other people's data.The need for adherence to suitable professional standards in the development, use and maintenance of computer systems The software of a computer is designed by teams of programmers who write thousands, even millions lines of code. These programmers need knowledge in programming and require organization and discipline. For this to happen development standards are set, such as a way of capturing what the system needs to do; ways of breaking up a system into manageable chunks; ways of keeping track of changes; ways of allocating staff; ways of finding and correcting errors; ways of planning and carrying out testsSummaryDedicated vs. General Purpose StandardsA dedicated system is a computer system that has a fixed purpose, for example, an engine management system within a car, or WIFI; a general purpose system is one that can be used to multiple purposes, such as a desktop computer, or a modern games console, which allows you to play video games, surf the web and even watch movies.StandardsProprietary StandardsProprietary standards are specifications for hardware or software that are controlled by one company, for example, Apple chargers made specifically for iPhones, iPads, etc. Advantages of this standard are that all appliances are of the same quality and never vary.Industry StandardsIndustry standards generally accepted requirements followed by the members of an industry, for example, a USB port. Advantages of this standard is that such appliances can be found anywhere where this appliance is regularly used.De Facto StandardsA de facto standard is something that is used so widely that it considered a standard for a given application even though it doesn't hold any official status. Examples of de facto software includes Microsoft Office applications and examples of de facto hardware include the QWERTY keyboard.Open StandardsOpen standards are when anybody can use it to the point where anybody can modify it, for example, Linux and 'http://'fundamentals of Computer Systems SummaryComputer systems have developed extremely quickly, in terms of human history. They have proven to be so useful that life without them would be unacceptable to most of us. Like any advance, they have generated their own special problems and we are gradually coming to terms with understanding and dealing with them.