1

• A little bit of History:
The idea of a universal machine
• Systematic problem solving
• Algorithms
2

• Programmability
• Binary Code (everything stored as “0” or “1”)
• Program and Data are represented in the same form
• Electronic Components
3

Early Computing History in a Nutshell
200 BC - today Abacus
~1670
Leibniz’
“Rechenmaschine”
~1750
1820
1838
1841
Jacquard’s Loom
Babbage’s
“Difference Engine”
Babbage’s
“Analytical Engine”
Ada Byron,
Lady Lovelace
-
Fixed calculations
+, -, *, /, sqrt
Punch Tape
Fixed
Table Calculation
Program & Data separate
First program
(Bernoulli-
Numbers)
4

• Gottfried von Leibniz
1670
• Add, subtract, multiply, divide, square roots
5

• Joseph Marie Jacquard 1804
• punch cards used to operate loom
6

• Charles Babbage
(1791-1871)
Design for the analytical engine
•
Programmable, but mechanical.
•
Data+Program separate
7

• Lady Ada Augusta
Byron, Countess of
Lovelace (1815-1952)
(1791-1871)
8

Early Computing History in a Nutshell
200 BC - today Abacus
~1670
~1750
Leibniz’
“Rechenmaschine”
Jacquard’s Loom
1820
1838
Babbage’s
“Difference Engine”
Babbage’s
“Analytical Engine”
1841 Ada Byron,
Lady Lovelace
-
Fixed calculations
Punch Tape
Fixed
Table Calculation
Program & Data separate
First program
(Bernoulli-
Numbers)
First universal programmable machine
9

Binary code universal electronic
Integration:
•fully electronic
•binary
•Programmable
•universal
1943
1946
1949
The Ancestors
1886
1936
1941-1944
1944
Hollerith Punch Cards
Zuse Z1 Relais
Zuse Z3/Z4
“Plankalkül”
Mark I Partly mechanic
Colossus
Eniac
Manchester
Universal
Computer
Not universal
Programmable with
Re-wiring
Cathode-Ray
Tube Memory
10

• Herman Hollerith (1860-1929)
• Invented a punched card device to help analyse the 1890 US census data
• Founded “Tabulating Machine Company”
1896
• 1924 – Tabulating Machine Company merges with others to form IBM
Binary but not really programmable
11

• 1936: Z1 first binary computer using
Erector Set parts, keyboard and lights for output (relay memory)
• 1938: Z2 – using punched tape and relays
Z1
Z3: fully binary, fully programmable, but partly mechanical 12

• 1943 British Colossus –
(1,500 vacuum tubes)
– Decipher enigma coded messages at 5,000 chars/sec
– At peak, 10 machines ran 24 hours a day in Bletchley Park
A German enigma coding machine
Fully electronic, but not universally programmable 13

• 1943-44 Aiken at Harvard/IBM “Mark 1” – first electromechanical digital computer (electromagnetic relays – magnets open and close metal switches)
(recreation of Analytical Engine)
– 8 ft tall, 50 ft long, 1 million parts
– 323 decimal-digit additions per sec
– storage for 72 23-digit numbers.
Universal, fully programmable
But partly mechanical
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• 18,000 tubes, 1500 sq ft
• Programmed by wire plugs into panels
– 5,000 decimal-digit additions/sec
– 20 10-decimal digit “accumulators”
Von Neumann and ENIAC
Fully electronic, programmable
But extensive-wiring required
15

• 1941 Von Neumann proposes
EDVAC – Electronic Discrete
Variable Computer
• Computer should
– Use binary
– Have stored programs
– Be function-oriented
• Team Members from
Bletchley Park and EDVAC/ENIAC collaborate at Manchester
• Add CRT display memory
First fully electronic universal computer
16

Process
Analysis
Problem specification
Design
Algorithm
Implementation
Program
Compilation
Executable
( solution
)
"Doctor, my head hurts"
Patient has elevated pressure in anterior parietal lobe
1. Sterilize cranial saw
2. Anaesthetize patient
3. Remove top of skull
4. Get the big spoon...
5. etc., etc. sterilize(saw,alcohol); raise_hammer(); lower hammer(fast); start(saw);
/* etc. etc. */
0100111010110010101010101
0010101010101001100101010
1010100101101001110101010
1010010010111010011110101
010111110101010001101…
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Process
" Doctor , my head hurts"
Analysis
Problem specification
Design
Algorithm
Implementation
Program
Compilation
Executable
(solution)
Patient has elevated pressure in anterior parietal lobe.
1. Sterilize cranial saw
2. Anaesthetize patient
3. Remove top of skull
4. Get the big spoon...
5. etc., etc. sterilize(saw,alcohol); raise_hammer(); lower hammer(fast); start(saw);
/* etc. etc. */
01001110101100101010101010010
10101010100110010101010101001
011010011101010101010010010111
010011110101010111110101010001
10100001101...
19

Process
Analysis
Problem specification
Design
Algorithm
Implementation
Program
Compilation
Executable
(solution)
20

• A sequence of instructions specifying the steps required to accomplish some task
• Named after:
of Khowarezm (now Khiva in Uzbekistan )
Circa 780-850 C.E. (Common Era)
21

Muhammad ibn Musa Al-Khwarizmi http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Al-Khwarizmi.html
• Book on arithmetic:
– Hindu numeration, decimal numbers, use of zero, method for finding square root
– Latin translation (c.1120 CE): “
Algoritm i de numero Indorum ”
• Book on algebra
–
Hisab al-jabr w’al-muqabala
22

• A sequence of instructions describing how to do a task
[ As opposed to actually executing the instructions]
23

• A cooking recipe
• Assembly instructions for a model
• The rules of how to play a game
• VCR instructions
•
Description of a martial arts technique
•
Directions for driving from A to B
• A knitting pattern
• A car repair manual
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• Recipe for Almond and honey slice
• Recipe for Arroz con pollo
25

Almond and Honey Slice
1/2 quantity Shortcrust
Pastry
185 g unsalted butter
100 g castor sugar
5 tablespoons honey
50 ml cream
50 ml brandy or any other liqueur or spirit
300 g flaked almonds
From: Stephanie Alexander, The
Cook’s Companion, Viking/Penguin,
Ringwood, Victoria, 1996, p. 349.
Preheat oven for 200° C
Line a 30 cm

20 cm baking tray with baking paper, and then with pastry
Bake blind for 20 minutes, then remove weights and foil
Turn oven up to 220° C.
Bring remaining ingredients to a boil, stirring.
Spread evenly over pastry.
Bake until topping is bubbling and has caramelised evenly, about 15 minutes.
Cool before cutting into fingers or squares.
26

Almond and Honey Slice
1/2 quantity Shortcrust
Pastry
185 g unsalted butter
100 g castor sugar in the order in which
5 tablespoons honey they are performed
(“executed”)
50 ml brandy or any other liqueur or spirit
300 g flaked almonds
From: Stephanie Alexander, The
Cook’s Companion, Viking/Penguin,
Ringwood, Victoria, 1996, p. 349.
Preheat oven for 200° C
Line a 30 cm

20 cm baking tray with baking paper, and then with pastry
Bake blind for 20 minutes, then remove weights and foil
Turn oven up to 220° C.
Bring remaining ingredients to a boil, stirring.
Spread evenly over pastry.
Bake until topping is bubbling and has caramelised evenly, about 15 minutes.
Cool before cutting into fingers or squares.
27

Cut chicken into pieces and brown the pieces on all sides in a casserole dish in hot olive oil.
Remove the chicken and to the juices in the casserole add garlic, onions and green peppers, and sauté until onion is golden.
Add bay leaf, whole tomatoes, and chicken broth.
When the broth boils add salt, saffron and rice.
Arrange chicken on rice, cover casserole and bake in a moderate oven
(350°F) for 20 minutes or until the rice is tender.
Add beans and artichokes during last 10 minutes of cooking.
From: “Arroz Con Pollo” in The
Margaret Fulton Cookbook, Hamlyn,
Sydney, 1968.
28

Cut chicken into pieces and brown the pieces on all sides in a casserole dish in hot olive oil.
Remove the chicken and to the juices in the casserole add garlic, onions and green peppers, and sauté until onion is golden.
Add bay leaf, whole tomatoes, and chicken broth.
When the broth boils add salt, saffron and rice.
Arrange chicken on rice, cover casserole and bake in a moderate oven
(350°F) for 20 minutes or until the rice is tender.
Add beans and artichokes during last 10 minutes of cooking.
From: “Arroz Con Pollo” in The
Margaret Fulton Cookbook, Hamlyn,
Sydney, 1968.
29

Cut chicken into pieces and brown the pieces on all sides in a casserole dish in hot olive oil.
Remove the chicken and to the juices in the casserole add garlic, onions and green peppers, and sauté until onion is golden.
Add bay leaf, whole tomatoes, and chicken broth.
When the broth boils add salt, saffron and rice.
Arrange chicken on rice, cover casserole and bake in a moderate oven
(350°F) for 10 minutes.
Add beans and artichokes.
Cover, and bake for another
10 minutes or until rice is tender.
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Problem
Algorithm : A sequence of instructions describing how to do a task (or process)
C Program
31

• Variables and values
• Instructions
– Sequences
– Procedures
– Selections
– Repetitions
Also required: Documentation
32

• Represent quantities, amounts or measurements
• May be numerical or alphabetical
(or other things)
• Often have a unit related to their purpose
• Example:
– Recipe ingredients
33

Almond and Honey Slice
1/2 quantity Shortcrust
Pastry
185 g unsalted butter
100 g castor sugar
5 tablespoons honey
50 ml cream
50 ml brandy or any other liqueur or spirit
300 g flaked almonds
From: Stephanie Alexander, The
Cook’s Companion, Viking/Penguin,
Ringwood, Victoria, 1996, p. 349.
Preheat oven for 200° C
Line a 30 cm

20 cm baking tray with baking paper, and then with pastry
Bake blind for 20 minutes, then remove weights and foil
Turn oven up to 220° C.
Bring remaining ingredients to a boil, stirring.
Spread evenly over pastry.
Bake until topping is bubbling and has caramelised evenly, about 15 minutes.
Cool before cutting into fingers or squares.
34

Almond and Honey Slice
1/2 quantity Shotcrust Pastry
185 g unsalted butter
100 g castor sugar
5 tablespoons honey
50 ml cream
50 ml brandy or any other liqueur or spirit
300 g flaked almonds
From: Stephanie Alexander, The
Cook’s Companion, Viking/Penguin,
Ringwood, Victoria, 1996, p. 349.
Preheat oven for 200° C
Line a 30 cm

20 cm baking tray with baking paper , and then with pastry
Bake blind for 20 minutes , then remove weights and foil
Turn oven up to 220° C .
Bring remaining ingredients to a boil, stirring.
Spread evenly over pastry.
Bake until topping is bubbling and has caramelised evenly, about 15 minutes .
Cool before cutting into fingers or squares.
35

• Are containers for values
– places to store values
• Example:
Variable Values
This jar can contain
10 cookies
50 grams of sugar
3 slices of cake etc.
36

• Variables may be restricted to contain a specific type of value
37


Values and Variables
• Instruction (a.k.a. primitive)
• Sequence (of instructions)
• Procedure (involving instructions)
• Selection (between instructions)
• Repetition (of instructions)
•
Documentation (beside instructions)
38

• Problem Solving Process
• Algorithms
• Components of Algorithms
– Values and Variables
– Instructions
– to be continued...
• Deitel & Deitel,
C: How to program
– Chapter 3, Sections 3.1 to 3.3
39