Transcript History of Computers

CSE 101
Computer Engineering Concepts & Algorithms
Lecture 1
Historical Thoughts
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Introduction
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What is a computer?
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Computer as a useful tool:
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Wide application area: Companies, Schools, Airports, Hospitals,
Banks, Military, Airports...
Quite new: A product of information age.
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Industrial age:Electricity, telephones, radio, automobiles, planes
Information age: Computers, Internet, Mobile Communication.
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Calculation and Computation
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Calculation:
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determining something by mathematical or logical methods
Transforming one or more inputs into one or more results.
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Multiply 7 and 8.
Computation:
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can be defined as finding a solution to a problem from given
inputs by means of an algorithm.
Denotes a more general process involving data and algorithms.
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Algorithm: A well-defined set of instructions to perform a certain
task.
A program that keeps records of students in a school and
answers queries about the data it keeps.
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Timeline of Computer Technology
1900 – 1800 BC
The first use of place-value number system
(eg the decimal system – value of the number depends
both on the digit itself and the position of the digit)
1000 – 500 BC
The invention of abacus: the first actual calculating
mechanism known to man
300 – 600 AD
The first use of the number 0, and negative numbers
(first appeared in India)
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Blaise Pascal
In 1640 Pascal started developing a
device to help his father add sums of
money.
The Arithmetic Machine could only add
and subtract, while multiplication and
division operations were implemented by
performing a series of additions or
subtractions.
Gottfried von Leibniz
Leibniz developed Pascal's ideas and,
in 1671, introduced the Step Reckoner,
a device which, as well as performing
additions and subtractions, could
multiply, divide, and evaluate square
roots by series of stepped additions.
Arithmetic machine (1642)
Step Reckoner (1671)
Pascal's and Leibniz's devices were the forebears of today's desk-top computers, and
derivations of these machines continued to be produced until their electronic equivalents
finally became readily available and affordable in the early 1970s.
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In the early 1800s, a French silk weaver called Joseph-Marie Jacquard invented a way
of automatically controlling the silk loom by recording patterns of holes in a string of
cards.
In the years to come, variations on Jacquard's punched cards would find a variety of
uses, including representing the music to be played by automated pianos and the
storing of programs for computers
IBM 80-column punched card format
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Charles Babbage
The first device that might be considered to be a computer in
the modern sense of the word was conceived in 1822 by the
eccentric British mathematician and inventor
Charles Babbage.
The Difference Engine, which was reconstructed in 1970s
from cast iron, bronze and steel, consisted of 4,000
components, weighed three tons, and was 10 feet wide and
6½ feet tall.
In Babbage's time, mathematical tables, such as logarithmic and trigonometric
functions, were generated by teams of mathematicians working day and night on
primitive calculators.
Due to the fact that these people performed computations they were referred to as
"computers."
In fact the term "computer" was used as a job description (rather than referring to the
machines themselves) well into the 1940s.
This term later became associated with machines that could perform the computations
on their own.
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The Difference Engine was actually only partially completed when Babbage
conceived the idea of another, more sophisticated machine called an Analytical
Engine (around 1830).
The Analytical Engine was intended to use loops of Jacquard’s punched cards to
control an automatic calculator, which could make decisions based on the results of
previous computations. This machine was also intended to employ several features
subsequently used in modern computers, including sequential control, branching, and
looping.
Working with Babbage was Augusta Ada Lovelace, the
daughter of the English poet Lord Byron. Ada, who was a
splendid mathematician and one of the few people who fully
understood Babbage's vision, created a program for the
Analytical Engine.
Had the Analytical Engine ever actually worked, Ada's
program would have been able to compute a mathematical
sequence known as Bernoulli numbers. Based on this work,
Ada is now credited as being the first computer programmer
and, in 1979, a modern programming language was named
ADA in her honor.
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George Boole
Boole made significant contributions in several areas of
mathematics, but was immortalized for two works in 1847 and
1854, in which he represented logical expressions in a
mathematical form now known as Boolean Algebra.
Boole's work was all the more impressive because, with the
exception of elementary school and a short time in a
commercial school, he was almost completely self-educated.
Boole’s work was only learned by Philosophy and Logic
students, until in 1938 Claude E. Shannon published an
article based on his master's thesis at MIT, where he
showed how Boole's concepts of TRUE and FALSE could
be used to represent the functions of switches in
electronic circuits.
Claude Shannon,
Creator of information theory
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Alan Turing
In 1937 Turing invented a theoretical computer as an abstract
"paper exercise."
This theoretical model, which became known as a Turing
Machine, was both simple and elegant, and subsequently
inspired many "thought experiments."
During World War II, Alan Turing worked as a cryptographer, decoding codes and ciphers at
one of the British government's top-secret establishments.
Turing was a key player in the breaking of the German's now-famous ENIGMA Code.
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1943 – 1947
ENIAC – Electronic Numerical Integrator and Calculator:
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1943 – 1947
ENIAC – Electronic Numerical Integrator and Calculator:
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It could do nuclear physics calculations (in two
hours) which it would have taken 100 engineers a
year to do by hand.
The system's program could be changed by
rewiring a panel.
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Johann von Neumann
In June 1944, the Hungarian- American mathematician Johann (John) Von
Neumann first became aware of ENIAC.
Von Neumann, who was a consultant on the Manhattan Project, immediately
recognized the role that could be played by a computer like ENIAC in solving
the vast arrays of complex equations involved in designing atomic weapons.
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In 1945, he published a paper titled “First draft of a report to the EDVAC”:
A memory containing both data and instructions. Also to allow both data and
instruction memory locations to be read from, and written to, in any desired order.
A calculating unit capable of performing both arithmetic and logical operations on
the data.
A control unit, which could interpret an instruction retrieved from the memory and
select alternative courses of action based on the results of previous operations.
The computer structure resulting from the criteria presented in the "First Draft" is popularly
known as a von Neumann Machine, and virtually all digital computers from that time
forward have been based on this architecture
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SMIL, one of the first Swedish computers, built at Lund University in the mid-fifties.
The original SMIL consisted of about 2000 vacuum tubes.
SMIL was the main university computer for more than 15 years and wasn't
decommissioned until 1972.
This picture shows SMIL as it looked in 1956.
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Two of the greatest inventions of the 20th century:
Transistors and Integrated Circuits
Formed from materials known as semi-conductors,
not very well understood until 1950s
They would be much smaller, lighter and would require less power than the vacuum
tubes that were being used until that time.
The world's first transistor,
invented at Bell Labs in 1947
Dr. John Bardeen, Dr. William Shockley, and
Dr. Walter Brattain, inventors
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Transistors, may range in number from 2 to more than 100,000, are integrated
together on pieces of silicon to produce Integrated Circuits to perform more
complex functions.
An integrated circuit contains transistors, capacitors, resistors and other parts packed in
high density on one chip.
The transistors, resistors, and capacitors are formed very small, and in high density on a
foundation of silicon.
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Microprocessors
The first microprocessor developed by Hoff contained
approximately 2,300 transistors and could execute 60,000
operations per second.
In 1973 Intel presented the first true general-purpose
microprocessor, which contained around 4,500 transistors and could
perform 200,000 operations per second, and destined to be the
central processor of many of the early home computers.
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1973
The Intel Corporation delivers the first integrated circuit
capable of executing a fully usable programme, the Intel 8080.
The microprocessor is born.
1977
The Apple Computer Company is started by two collegedropouts in their garage, Steve Jobs and Steve Wozniak.
The machine uses inexpensive parts and home color television.
The BASIC programming language is written by Bill Gates of
Microsoft.
1981
Microsoft provides the Disk Operating System (DOS) for
the IBM Personal Computer
Late 1980s
The use of Windows operating shell produced by Microsoft
provides a Graphical User Interface (GUI) for users
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Computers can be generally classified by size and power, though there is considerable
overlap:
personal computer : A small, single-user computer based on a microprocessor. In
addition to the microprocessor, a personal computer has a keyboard for entering data, a
monitor for displaying information, and a storage device for saving data.
workstation : A powerful, single-user computer. A workstation is like a personal
computer, but it has a more powerful microprocessor and a higher-quality monitor.
minicomputer : A multi-user computer capable of supporting from 10 to hundreds of
users simultaneously.
mainframe : A powerful multi-user computer capable of supporting many hundreds or
thousands of users simultaneously.
supercomputer : An extremely fast computer that can perform hundreds of millions of
instructions per second.
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The actual machinery -- wires, transistors, and circuits is called the hardware;
the instructions and data are called software.
All general-purpose computers require the following hardware components:
memory : Enables a computer to store, at least temporarily, data and programs.
mass storage device : Allows a computer to permanently retain large amounts of data.
Common mass storage devices include disk drives.
input device : Usually a keyboard and mouse, the input device is the conduit through
which data and instructions enter a computer.
output device : A display screen, printer, or other device that lets you see what the
computer has accomplished.
central processing unit (CPU): The heart of the computer, this is the component that
actually executes instructions. (If the CPU is built around a microprocessor device, it is
also referred to as a Microprocessor Unit, MPU)
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