Know the fundamental logic circuits So that You understand how computers process data We’ve been looking at how data is stored as binary. What about how it’s processed?

A NOT gate: it inverts the signal. 1 becomes 0 and 0 becomes 1! ABCQ Truth table A B C Q

ABCDQ

Logic grids — 1 Three variables: Name, lunch type, sitting Who had a late lunch? Fred When is the packed lunch sitting? Late sitting (Note: all variables in these types of grids must be mutually exclusive: So Fred can’t be Sally! Early can’t be late! So for this example, Why can’t Sally be in the late sitting Because she can’t have school dinner late

Logic grids — 2 Questions 1.What are the three variables in this grid? Name, time activity 2.What activity was before the Cinema? 3.What activity was 2 hours after Bowling? 4.What did Fred do and at what time? 5.What did Sam do and at what time? 6.What would the incomplete part of the grid look like?

What’s going on here? The four symbols are called logic gates. There are four different types here. Try and work out what each one does.