fundamentals of computer systems

computer systems

• computer- electronic programmable data processing machine
• system- collection of parts that work together for some defined purpose
• computer system- collection of hardware and software that works together to achieve some data processing task
• systems recieve inputs from the outside
• they process these inputs
• they output the results of the processing
• a system is separated from the outside work by a system boundary
• boundaries are often called interfaces

importance of computer systems

• improved quality in manufacturing- robotic machinery is more accurate than humans
• cheaper manufacturing- automation reduces wage costs and allows 24/7 working
• faster access to information- many jobs can be done more quickly
• better decision making- with lots of facts organised and available, decisions can be better informed
• new ways of doing business- more buying online, more choice, cheaper goods, facilities such as the internet and ATM's would not be possible without computer systems
• new ways of communicating- email, SMS, cell phones, are being developed all the time

examples of computer systems

car engine management

• inputs- temperature, CO2 levels, speed
• outputs- signals to carburettor, data to engine diagnostics
• processing- check values against set parameters, produce fault codes

holiday booking

• inputs- dates, destinations, credit card details
• outputs- itineraries, air tickets, hotel reservations
• processing- check availability, produce documents

washing machine

• inputs- temperature, water levels, dirtiness
• outputs- signals to motor, heater, timer
• processing- check values, determine washing parameters

satnav

• inputs- signals from satellites, inputs from user
• outputs- route, places of interest, warnings
• processing- check position, locate on map, output map

atm

• inputs- card details, PIN, user requests
• outputs- balance, cash
• processing- check balance, adjust balance of account

travel card

• inputs- location of station, bus route number, top-up information, money
• outputs- open gate to station, display balance
• processing- calculate journey cost, adjust balance

types of computer system

general purpose systems

• designed to perform multiple tasks
• various applications can be loaded so that they can be used for a wide variety of purposes

dedicated systems

• specially produced to perform a single function or set of functions

control systems

• computer systems that control machinery
• particularly important in manufacturing processes
• increasingly part of common domestic and personal gadgets
• industrial robots are an important application of control systems

embedded systems

• computer systems that are part of a larger system
• usually also control systems
• include portable devices
• digital watches, satnavs, cameras, mp3 players
• also include larger installations
• traffic lights, controllers of machinery in factories
• can be very simple or highly complex

expert systems

• computer systems designed to behave like a human expert
• knowledge base- database of facts
• inference engine- software that makes deductions using the knowledge base
• interface- allows a human user access to the system
• commonly used for diagnosing diseases, finding faults in machinery, choosing complex products, suggesting purchases to consumers and making credit checks

management information systems

• bring together the information from all parts of an organisation so that managers can make sensible decisions
• cover technology, data, people
• typically produce regular reports based on the organisation's data
• Decision Support Systems
• Executive Information Systems
• Office Automation…