1. National Diploma Unit 4 Introduction to Software Development Input and output processing

2. Input devices Within the Windows environment, mouse and keyboard are the default Other specialist devices may be required e.g. OMR Optical Mark Readers Barcode scanners Sensors e.g. temperature

3. Input interface Think about how the user is going to use the program What will they need to do first? What features will they need? Can they easily undo a mistake? What kind of help will be needed? How can I design the program so that it is easy to use and learn?

4. Validation How can I determine that the data that they enter is reasonable? What are the tolerance limits? What formatting is needed of input data? Do I allow null data to be added? E.g. zeros and empty text boxes

5. Output processing Key output devices are the VDU and printer Output may also be stored in a file on a disc Sound output may also be required It may also be sent to devices such as motors, buzzers or lamps

6. Output processing Similar rules apply to input Is there any way of checking that the output is reasonable? What kind of formatting is required? Am I required to show null values? What happens if there isn’t enough room on the disc to store the data? How will my output be displayed on different size screens/ different resolution or different printers?

7. Exercise Consider the program from last time (the sick pay calculator) On paper, design the input and output for this system Address all of the questions about input and output processing in the previous slides

8. Exercise Consider some specialist input devices Voice recognition Touch screen Optical Mark Readers Optical Character Readers Bar code scanners Give one use for each and give one advantage and one disadvantage