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!

A B C Q

0 0 0 0

0 0 1 0

0 1 0 1

0 1 1 0

1 0 0 1

1 0 1 0

1 1 0 1

1 1 1 0

Truth tableTruth table

A

B

C

Q

A B C D Q

0 0 0 0 1

0 0 0 1 0

0 0 1 0 0

0 0 1 1 0

0 1 0 0 1

0 1 0 1 0

1 1 0 1 1

1 1 1 1 1

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 sittingBecause she can’t have school dinner late

Pack

ed P

unch

Scho

ol d

inne

r

early

sitti

ng

late

sitti

ngFred x o o xSally o x x o

early sitting o x

late sitting x

Nam

eSi

tting

Type Sitting

Logic grids — 2Questions

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?

Fred

Sally

Sam

Cine

ma

Pizz

a

Bow

ling

17:00 o o x

18:00 x o o

19:00 o x o

Cinema x o oPizza o o x

Bowling o x o

ActivityName

Tim

eAc

tivity

What’s going on here?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.