1. Maths and the History of ICT

2. Charles Babbage 1791-1871 English Mathematician and Philosopher
Originated the concept of a programmable computer

3. Computers
In Babbage’s day a ‘computer’ was a person who was good at arithmetic and was employed to work out the results of calculations.
There were many errors, so Babbage set out to build a machine that could do the calculations. It used the concept of ‘finite differences’ so avoided the need for multiplication and division.

4. Babbage’s Difference Engine
Part of Babbage’s Difference Engine

5. Babbage’s Difference Engine
A Difference Engine built from Babbage’s design. It weighs kg.

6. Babbage’s Brain
Babbage died at the age of 79. His brain was cut in two. Half of it is preserved at the Hunterian Museum in the Royal College of Surgeons in London. The other half is on display in the Science Museum, London.

7. Ada Lovelace 1815-1852 English Writer Daughter of poet Lord Byron
The first computer programmer

8. Ada Lovelace
Although she never saw Babbage’s Difference Engine completed, she wrote the first computer program for it for finding Bernoulli Numbers.
In 1980 a computer language used by the US Department of Defence was named after her: ‘Ada’.
March 24 is commemorated by some as Ada Lovelace Day. This is a day to celebrate the achievements of woman in technology and science.

9. George Boole 1815-1864 English Contributed to:
Logic
Maths philosophy
Married daughter of George Everest
Developed Boolean Logic

10. Boolean Logic
This is a special algebra which uses the values 1 and 0 only. These values 1 and 0 are sometimes called ‘true’ and ‘false’.
There are a number of operations, the primary ones are: and &
or ||
not ¬
xor ⊕ (called exclusive-or)
This logic is at the heart of your computer and helps it make decisions and do arithmetic.

11. Boolean Logic p q p & q True False
The operations can be shown in ‘truth tables’. This is the truth table for the operation and: p q
p & q
True
False
The result is True when both p and q are True.
If 1s and 0s are used it is the same as multiplication

12. Boolean Logic p q p || q True False
This is the truth table for the operation or: p q
p || q
True
False
The result is True when either p or q are True.

13. The result is the opposite of p.
Boolean Logic
This is the truth table for the operation not: p ¬p
True
False
The result is the opposite of p.

14. Boolean Logic p q p ⊕ q True False
This is the truth table for the operation xor: p q
p ⊕ q
True
False
The result is True when either p or q are True but not when they are both True.

15. This combination is called NAND (i.e. not and)
Boolean Logic
This combination is called NAND (i.e. not and)
Some combinations of operations can be show to be equivalent to other combinations. p q
¬(p & q)
¬p || ¬q
True
False

16. Alan Turing 1912-1954 English Contributed to:
Logic
Cryptanalysis
Computing
Broke war codes created by the German ‘Enigma’ machine
Significant in creation of the modern computer

17. Bombe