History of Computing
INTRODUCTION
It took thousands of years for the computer to
develop in to the present state.
 Earlier the process of computing was done by
counting with their own figures, stones & through
scratches on the sand or walls. But this idea is
only for the counting of small entities.
 Later, various types of computing devices such as
ABACUS, Napier's bone slide rule, diffence engine,
lady Augusta Ada Lovelace, etc. On the processing
of previous calculating machines & continuous
development on them, makes modern computer
come to this stage

PRIMATIVE CALCULATORS
THE ABBACUS
EARLY COMPUTATIONAL DEVICES

(Chinese) Abacus
 Used
for performing arithmetic operations
AL’KHOWARIZMI AND THE
ALGORITHM




12th Century Tashkent Cleric
Developed the concept of a
written process for doing
something
Published a book on the
process of algorithms
The basis of software
EARLY COMPUTATIONAL DEVICES

Napier’s Bones, 1617
 For
performing multiplication & division
John Napier
1550-1617
PHILOSOPHER FOREFATHERS OF
MODERN COMPUTING
1600-1700
 Von Leibniz developed
Blaise
Pascal –
developed the
Pascaline.
Desk
top calculator
worked lik an
odometer.

binary arithmetic and a
hand cranked
calculator.
Calculator was able to
add, subtract, multiply
and divide.
BLAISE PASCAL

Pascal (1623-62) was the son of a tax collector
and a mathematical genius. He designed the
first mechanical calculator (Pascaline) based
on gears. It performed addition and
subtraction.
EARLY COMPUTATIONAL DEVICES

Pascaline mechanical calculator
Blaise Pascal
1623-1662
EARLY COMPUTATIONAL DEVICES

Slide Calculators
William Oughtred
1574-1660
GOTTFRIED WILHELM VON LEIBNIZ
Leibnitz (1646-1716) was a German
mathematician and built the first calculator to
do multiplication and division. It was not
reliable due to accuracy of contemporary parts.
 He also documented the binary number system
which is used in all modern computers.

COUNT TO 8 IN BINARY
0001
 0010
 0011
 0100
 0101
 0110
 0111
 1000

MODERN COMPUTERS USE BINARY

Why?
 Much
simpler circuits needed for performing
arithmetic
EARLY COMPUTATIONAL DEVICES

Leibniz’s calculating machine, 1674
Gottfried Wilhelm von Leibniz
1646-1716
GEORGE BOOLE (1815-1864)

Invented Boolean Algebra





System of logic using boolean values
Used to establish inequalities:
symbolic use of <, or >, or <>
Used in computer switching
Modern use in library searches
CHARLES BABBAGE

Babbage (1792-1872) was a British inventor
who designed an two important machines:
 Difference
engine
 Analytical engine

He saw a need to replace the human
computers used to calculate numerical tables
which were prone to error with a more accurate
machine.
CHARLES BABBAGE

Difference engine
 Designed
to compute values of polynomial
functions automatically
 No multiplication was needed because he used the
method of finite differences
 He never built one
 It was built from 1989 – 1991 for the London
Science Museum
CHARLES BABBAGE DIFFERENCE ENGINE
CHARLES BABBAGE
THE NEXT LEAP FORWARD
1800’S
CHARLES BABBAGE

Analytical Engine
 Could
be programmed using punch cards – totally
revolutionary idea
 Sequential control / branching / looping
 Turing complete
The analytical engine
of Charles Babbage
LADY ADA BYRON – WORLD’S FIRST
PROGRAMMER





Countess of Lovelace,
daughter of Lord Byron.
One of the first women
mathematicians in England
Documented Babbage’s
work.
Wrote an account of the
difference engine.
Wrote a program for the
difference engine for
computing Bernoulli numbers
HERMAN HOLLERITH

Hollerith developed an electromechanical punched-card
tabulator to tabulate the data for 1890 U.S. census. Data
was entered on punched cards and could be sorted
according to the census requirements. The machine was
powered by electricity. He formed the Tabulating Machine
Company which became International Business Machines
(IBM). IBM is currently the largest computer manufacturer,
employing in excess of 300,000 people.
HERMAN HOLLERITH PUNCH CARD
TABULATING MACHINE
1890 CENSUS
HOLLERITH TABLES AND THE CENSUS
Improved the
speed of the
census
Reduced cost by
$5 million
Greater accuracy
of data collected
Hollerith –
unemployed after
the census
KONRAD ZUSE - FIRST CALCULATOR 1938
THE WAR YEARS 1939-1945
TWO PRIMARY USES

Artillery Tables



Hand calculation replaced by machine calculation
Department of the Navy
Cryptologist :
Cryptography
The art or process of writing in or deciphering secret writing
Bletchley House
The Enigma Codes – U23

THE BRITISH EFFORT
HISTORY OF COMPUTERS




Alan Turing was a British mathematician who also made significant
contributions to the early development of computing, especially to the
theory of computation.
He developed an abstract theoretical model of a computer called a
Turing machine which is used to capture the notion of computable i.e.
what problems can and what problems cannot be computed.
Not all problems can be solved on a computer.
Note: A Turing machine is an abstract model and not a physical
computer
ALAN TURING
MISUNDERSTOOD GENIUS
1936


Published a paper “On
Computable Numbers”
Turing’s machine hypothetical computer
that could perform any
computation or logical
operation a human
could devise.
TURINGS HERITAGE



Code breaking was
Touring’s strength.
Colossus a computer to
break the German
enigma code - 100
Billion alternatives.
Ran at rate of 25,000
characters per second
THE UNITED STATES EFFORT
THE II WORLD WAR YEARS
1945




Calculate artillery tables.
Used to break codes like
the Colossus.
Used to model future
events - Atomic and
Hydrogen Bombs.
Cmdr. Grace Hooper
1939 -
HOWARD AIKEN (1900 – 73)


Aiken, a Harvard professor, with the backing of IBM
built the Harvard Mark I computer (51ft long) in 1944. It
was based on relays (operate in milliseconds) as
opposed to the use of gears. It required 3 seconds for a
multiplication.
Aiken’s Mark 1. (1944) based on Babbage’s original
design - built at IBM labs, electro-mechanical, weighed
5 tons. Admiral Grace Hopper worked as programmer
on this computer, and coined the term 'bug' for a
computer fault.
HARVARD MARK - 1, 1944
THE MARK I - A DINOSAUR





51 feet long
3,304 electro mechanical
switches
Add or subtract 23 digit
numbers in 3/10 of a
second.
Instructions (software)
loaded by paper tape.
The infamous “Bug”
ENIAC - THE NEXT JUMP FORWARD 1946






1st electronic digital computer
Operated with vacuum tubes
rather electro-mechanical
switches
1000 times faster than Mark I
No program storage - wired
into circuitry.
This was still based on the
decimal numbering system.
“programmed” by switches
and cords
ENIAC
THE ADVENT OF THE
SEMICONDUCTOR - 1947


Developed at Bell Labs
by Shockley & Bardeen –
Nobel Prize
Point Contact Transistor
replaced power hungry,
hot and short lived
vacuum tubes
HISTORY OF COMPUTERS



Von Neumann was a scientific genius and was a consultant on the
ENIAC project. He formulated plans with Mauchly and Eckert for a new
computer (EDVAC) which was to store programs as well as data.
This is called the stored program concept and Von Neumann is credited
with it. Almost all modern computers are based on this idea and are
referred to as Von Neumann machines.
He also concluded that the binary system was more suitable for
computers since switches have only two values. He went on to design
his own computer at Princeton which was a general purpose machine.
COMPUTER
GENERATIONS
st

1 generation computers


Vacuum tube, 1946-1957, 40K operations/sec
2nd generation computers

Transistor, 1958-1964, 200 K operations/sec
Smaller, cheaper, less heat dissipation
 William Shockley et al. in 1947 at Bell Labs


3rd generation computers


4th generation computers


SSI, MSI, 1965-1971, 1 M operations/sec
LSI, 1972-1977, 10 M operations/sec
5th generation computers

VLSI, 1978 to date, 100 M operations/sec
FIRST GENERATION COMPUTERS (1951-58)


These machines were used in business for accounting and
payroll applications. Valves were unreliable components
generating a lot of heat (still a problem in computers).
They had very limited memory capacity. Magnetic drums
were developed to store information and tapes were also
developed for secondary storage.
They were initially programmed in machine language
(binary). A major breakthrough was the development of
assemblers and assembly language.
EDVAC - ELECTRONIC DISCREET VARIABLE
AUTOMATIC COMPUTER 1951



Data stored internally on
a magnetic drum
Random access
magnetic storage device
First stored program
computer
THE 50’S THE ERA OF ADVANCES
SECOND GENERATION
(1959-64)



The development of the transistor revolutionised the development of
computers. Invented at Bell Labs in 1948, transistors were much
smaller, more rugged, cheaper to make and far more reliable than
valves.
Core memory (non-volatile) was introduced and disk storage was also
used. The hardware became smaller and more reliable, a trend that still
continues.
Another major feature of the second generation was the use of high-level
programming languages such as Fortran and Cobol. These
revolutionised the development of software for computers. The
computer industry experienced explosive growth.
TECHNICAL ADVANCES IN THE 60’S





John Mccarthy coins the term “Artificial Intelligence”
1960 - Removable Disks appear
1964 - BASIC - Beginners-all purpose Symbolic Instruction
Language
Texas Instruments offers the first solid- state hand-held
calculator
1967 - 1st issue of Computerworld published
THIRD GENERATION
(1965-71)



IC’s (Integrated Circuits) were again smaller, cheaper, faster and more
reliable than transistors. Speeds went from the microsecond to the
nanosecond (billionth) to the picosecond (trillionth) range. ICs were used
for main memory despite the disadvantage of being volatile.
Minicomputers were developed at this time.
Terminals replaced punched cards for data entry and disk packs
became popular for secondary storage.
IBM introduced the idea of a compatible family of computers, 360
family, easing the problem of upgrading to a more powerful machine
THIRD GENERATION
(1965-71)



Substantial operating systems were developed to manage and share the
computing resources and time sharing operating systems were
developed. These greatly improved the efficiency of computers.
Computers had by now pervaded most areas of business and
administration.
The number of transistors that be fabricated on a chip is referred to as
the scale of integration (SI). Early chips had SSI (small SI) of tens to a
few hundreds. Later chips were MSI (Medium SI): hundreds to a few
thousands,. Then came LSI chips (Large SI) in the thousands range.
MOORE’S LAW

In 1965 Gordon Moore graphed data about growth in memory
chip performance.

Realized each new chip roughly twice capacity of predecessor,
and released within ~2 yrs of it => computing power would rise
exponentially over relatively brief periods of time.

Still fairly accurate. In 30 years, no of transistors on a chip has
increased ~20,000 times, from 2,300 on the 4004 in 1971 to
42 million on the Pentium® IV.
THE 1970’S - THE MICROPROCESSOR
REVOLUTION


A single chip containing
all the elements of a
computer’s central
processing unit.
Small, integrated,
relatively cheap to
manufacture.
THE SUPER COMPUTERS





The Cray
Parallel processing power
Speed 100 million
arithmetical functions per
second
Sensitive to heat - cooled with
liquid nitrogen
Very expensive
- 1972
FOURTH GENERATION


VLSI allowed the equivalent of tens of thousand of
transistors to be incorporated on a single chip. This led to
the development of the microprocessor a processor on a
chip.
Intel produced the 4004 which was followed by the
8008,8080, 8088 and 8086 etc. Other companies
developing microprocessors included Motorolla (6800,
68000), Texas Instruments and Zilog.
FOURTH GENERATION





Personal computers were developed and IBM launched
the IBM PC based on the 8088 and 8086
microprocessors.
Mainframe computers have grown in power.
Memory chips are in the megabit range.
VLSI chips had enough transistors to build 20 ENIACs.
Secondary storage has also evolved at fantastic rates with
storage devices holding gigabytes (1000Mb = 1 Gb) of
data.
FOURTH GENERATION




On the software side, more powerful operating systems
are available such as Unix.
Applications software has become cheaper and easier to
use.
Software development techniques have vastly improved.
Fourth generation languages 4GLs make the development
process much easier and faster.
FOURTH GENERATION



Languages are also classified according to generations
from machine language (1GL), assembly language (2GL),
high level languages (3GL) to 4GLs.
Software is often developed as application packages.
VisiCalc a spreadsheet program, was the pioneering
application package and the original killer application.
Killer application: A piece of software that is so useful that
people will buy a computer to use that application.
THE ALTAIR FROM A VOYAGE TO ALTAIR STAR TREK -1975
THE BIRTH OF THE MICRO
COMPUTER 1975




Jobs and Wozniac develop
the Apple II
Commodore PET, programs
stored on a cassette
Tandy-Radio Shack TRS-80
5 1/2 inch floppy disk
becomes the standard for
software
FINALLY, THE COMPUTER AS MAN OF THE
YEAR - 1982
REVENGE OF THE NERDS
Bill Gates
Microsoft, 1978
Steve Jobs
Steve Wozniak
Alan Turing