This document discusses binary logic and how logic gates work in computing. It introduces the logic gates NOT, AND, and OR and how their inputs affect their outputs. It provides examples of logic diagrams and truth tables. It also presents a scenario of a car warning system and challenges the reader to represent the system with logic gates and a truth table.

1. Binary Logic A451 – 2.12 Computer Hardware

2. Get your brains logged on Why do computers use binary?

3. Binary and computers

4. You need to be able to: explain why data is represented in computer systems in binary form understand and produce simple logic diagrams using the operations NOT, AND and OR produce a truth table from a given logic diagram.

5. NOT, AND, OR How does each gate work? How does the input(s) affect the output? a b a b NOT AND OR

6. Binary Logic Simulator http://logic.ly/demo

7. NOT, AND, OR Gates NOT AND OR

8. Logic Diagram Activity Without using the computer … complete the truth table for diagrams 1 to 3 on your worksheet.

9. Logic Diagram Activity Check your answers by using the logicly website to re-create the logic diagrams. http://logic.ly/demo

10. Car Safety System Scenario The car warning light turns on until: Driver’s seatbelt is fastened All doors are shut If night time, headlights should be on. Extension

11. Car System Solution

12. Headlight Extension Solution

13. Challenge Using the XOR (exclusive OR) could you adapt your logic diagram to check if all occupied seats have their seatbelts fastened .

14. Which truth table? A B C A B Output 0 0 0 0 1 1 1 0 1 1 1 0 A B Output 0 0 0 0 1 1 1 0 1 1 1 1 A B Output 0 0 0 0 1 0 1 0 0 1 1 1

15. Which truth table? A B C A B Output 0 0 1 0 1 1 1 0 1 1 1 0 A B Output 0 0 1 0 1 0 1 0 0 1 1 0 A B Output 0 0 0 0 1 0 1 0 0 1 1 1

16. Which truth table? A B C A B Output 0 0 1 0 1 0 1 0 1 1 1 0 A B Output 0 0 0 0 1 0 1 0 0 1 1 1 A B Output 0 0 1 0 1 0 1 0 0 1 1 0

17. Recap – can you: explain why data is represented in computer systems in binary form understand and produce simple logic diagrams using the operations NOT, AND and OR produce a truth table from a given logic diagram.