by the end of this lesson you will be able to:
- Understand what a computer system is
- Identify different types of computer systems
- Create algorithms and identify the inputs, process and outputs of each
Input
The role of an input in a computer system is to provide data for further processing.
An input consists of data or commands that are entered into the computer system usually via an input device such as a keyboard, mouse, OMR, barcode reader, scanner etc…
The input data is converted into digital data that can be dealt with by the computer. Sometimes the input is already in digital format, for example when it has been transmitted from another computer but most of the time it needs to be converted into a digital format before processing can take place.
Process
The central part of a computer system is ‘processing’. Processing is the stage where the input data is manipulated in order to produce meaningful information. Processing can include a number of stages such as sorting, searching, calculations, graphing. The results obtained from processing the data can then be used in the next stage, called “output”.
Some examples of processing could include:
- searching sales data to find which products in a supermarket have sold the most
- sorting a list of customer data into alphabetical order
- after a barcode has been scanned (input), retrieving the price of the item from the supermarket database and using this data to calculate the customer’s bill
- sorting a list of customer data into alphabetical order
autotune software: You are at a concert of a world famous singer. The singer knows their voice is a bit wonky this evening with some ‘off’ notes. So they use a computer processing system between the microphone and the main sound system to ‘correct’ these duff notes in real-time. The audience enjoys a perfect rendition. This is real-time processing in action.
Output
Output is the stage where the information obtained via processing is presented to the user in a suitable format.
Most outputs involve converting digital data into some physical effect that the person senses with eyes or ears. This means that you might be able to see the output, perhaps a print out or displayed on the computer screen. Maybe you can hear the output via music, voice instructions or a computer generated alarm.
Examples of output could include:
- a printout of student examination results displayed in order from highest to lowest
- a digital display at the petrol pump showing how much fuel has been delivered and the cost of that fuel
- an alarm from a fire alarm system which has detected smoke in the room
- a digital display at the petrol pump showing how much fuel has been delivered and the cost of that fuel
The other kind of output is where the data remains in digital form such as sending data directly to another computer. But eventually the data has to be converted to a form that a person can use.