1. Activity 1 Research / Revise how RAM stores DATA 5 minutes 1 0

2. Binary Logic What is Binary?

3. Introduction to Binary Remembering how RAM store data? Ram holds data using capacitors and transistors. A capacitor can be thought of as a sink or bucket holding water. When it is full it’s holding a ‘bit’ of data (1), when it is empty it represents a zero (0). But obviously in RAM it holds an electrical current (not water). The transistor acts as a switch that lets the computer read the what is in the capacitor (bucket) or fill it up or empty it (change its state). http://www.howstuffworks.com/ram.htm Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram 1 0

4. How Capacitors and Transistors Work – a brief overview! Current (electrical flow) Capacitor (holding current) Transistor (switch allowing current to escape) When capacitor is full it represents a ‘ 1 ’ (data) When capacitor is empty it represents a ‘ 0 ’ (data) No Current Flow Current Escapes Capacitor Empties

5. What is Binary? So What is Binary? So we have just seen how capacitors and transistors store data in the RAM... …well, it is exactly the same in the CPU. The CPU is made up of millions of tiny switches (transistors) which are either: on/closed, (1) or off/open (0). Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram

6. What is Binary? So What is Binary? Because humans have 10 fingers, we count using a denary number system (base 10): We count to ten… Then we record it by placing a 1 in the 10s column… …and when we get to 100, we make a record of it by placing a 1 in the 100s column…and so on! Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram 123 4 56 7 8 9 123 4 56 7 8 9 1 2 123 4 56 7 8 9 0 0

7. What is Binary? So What is Binary? Computers don’t have 10 fingers, instead they have two states: electricity present (switch is on ) Or electricity not present (switch is off ). So computers count to two, then count to two again and so on… And for this reason, computers use the binary number system (zeros (0) and ones (1)). Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram

8. What is Binary? So What is Binary? This is how we (like computers) count in binary We count to 2… Then we record it by placing a 1 in the 2s column… …and when we get to 2 sets of 2s, we make a record of it by placing a 1 in the 4s column…and so on! Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram 1 0 1 1 0 1 0 01 1 0 1 1 0 00 1 1 0 1 1 00 1 10 1 100 0 0 …and so on!

9. What is Binary? Summary Computers represent numbers using zeros and ones (binary). This is because CPUs are made up of millions of tiny switches that have only 2 states (on or off, open or closed, true or false) Because of this computers can’t count higher than 2 without using a different number system – the binary number system. Here our number columns, instead of being units, tens, hundreds… are actually units, twos, fours, eights etc. Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram

10. Summary Video http://www.youtube.com/watch?v=kcTwu6TFZ08

11. TwosOnes 10

12. What is Binary? Summary Computers represent numbers using zeros and ones (binary). This is because CPUs are made up of millions of tiny switches that have only 2 states (on or off, open or closed, true or false) Because of this computers can’t count higher than 2 without using a different number system – the binary number system. Here our number columns, instead of being units, tens, hundreds… are actually units, twos, fours, eights etc. Learning Objectives: (a)Explain why data is represented in computer systems in binary form (b)Understand and produce simple logic diagrams using the operations NOT, AND and OR (c)Produce a truth table from a given logic diagram

13. Activity 2 Create a poster which clearly shows the following: 1.Why computers need to have their own number system (why they can’t use our ‘base 10’ number system). 2.An example of a binary number which is fully explained (in other words, how do we read the binary number). 30 minutes

14. Final Questions Explain why data is stored in computers in binary form (3 marks) Explain, in your own words and in as much detail as possible, how we read the following binary number: 1011 (3 marks) What is the value of the following binary number and how did you work it out? 10011 (2 marks)