This document provides a brief history of computers from ancient times to the development of mainframes. It discusses early mechanical calculating devices like the abacus and slide rule. It then covers the development of mechanical computers in the 17th-18th centuries and early electromechanical computers. A key focus is the development of programmable computers in the 1940s, including ENIAC, EDSAC, and the work of pioneers like Turing. The document concludes with the transition to transistor-based computers in the 1950s.

1. Universidade PresbiterianaUniversidade Presbiteriana
MackenzieMackenzie
A Brief History of Computers
From the early days to the mainframes
Faculdade de Computação e Informática
São Paulo, Brasil

2. Prof. Dr. Vivaldo José
Breternitz
Acad. Marta D.
Magalhães Santos
Prof. Esp. Elisabete
Panssonatto Breternitz

3. To plan your future wisely is necessary to
know the past of the tools you will use

4. Sometimes planning is difficult since we face the arrogance of the
owners of the truth…
• "I think there is a world market for maybe five computers.“ - Thomas Watson, chairman of
IBM, 1943
• "Computers in the future may weigh no more than 1.5 tons.“ - Popular Mechanics,
forecasting the relentless march of science, 1949
• "I have traveled the length and breadth of this country and talked with the best people,
and I can assure you that data processing is a fad that won't last out the year.“ - The editor
in charge of business books for Prentice Hall, 1957
• "There is no reason anyone would want a computer in their home.“ - Ken Olson,
president, chairman and founder of Digital Equipment Corp., 1977
• "640k ought to be enough for anybody.“ - Bill Gates, 1981
• "We don't like their sound, and guitar music is on the way out.“ - Decca Recording Co.
rejecting the Beatles, 1962.

5. So, let's talk a little
about the history of
computers – maybe
it can help you…

6. The early days

7. Abacus – c. 4000 BCE
On the left, you see two abacuses (abaci is
also correct). On both abacuses, we see the
number 1998. The top area of each abacus
is used for fives, and the bottom area is
used for ones. Abacuses are used for doing
arithmetic. When doing arithmetic, you
move the beads. The position of the beads
represents the sum, or product, so far. It is
how you can remember the partial sum or
product.
Experts in the use of the abacus can be very
fast (and accurate), often faster than an
expert with a calculator, especially addition
and subtraction.
The abacus is still a mainstay of basic
computation in some societies.

8. Slide rules
The slide rule, also known colloquially as a slipstick,is a
mechanical analog computer. The slide rule is used
primarily for multiplication and division, and also for
functions such as roots, logarithms and trigonometry, but is
not normally used for addition or subtraction.
William Oughtred and others developed the slide rule in the
17th century based on the emerging work on logarithms by
John Napier.
Napier

9. Before the advent of the pocket
calculator, the slide rule was the
most commonly used calculation
tool in science and engineering.
The use of slide rules continued
to grow through the 1950s and
1960s even as digital computing
devices were being gradually
introduced; but around 1974 the
electronic scientific calculator
made it largely obsolete and most
suppliers left the business.

10. Wilhelm Schickard (1592 –1635) was
a German scientist who designed a
calculating machine in 1623.
Unfortunately a fire destroyed the
machine as it was being built in 1624
and Schickard decided to abandon his
project.
Unknown to the world for more than
three centuries it was rediscovered in
1957 and therefore had no impact on
the development of mechanical
calculators

11. Blaise Pascal, a famous French
philosopher and mathematician
invented the first digital calculator, the
Pascaline, to help his father with his
work collecting taxes.
He worked on it for three years between
1642 and 1645.
The device resembled a mechanical
calculator of the 1940's. It could add
and subtract by the simple rotation of
dials on the machine’s face.

12. Gottfried Wilhelm Leibniz (1646 –1716) was a
German philosopher and mathematician.
While working on adding automatic multiplication
and division to Pascal's calculator, he was the first
to describe a pinwheel calculator in 1685 and
invented the Leibniz wheel, used in the
arithmometer, the first mass-produced mechanical
calculator.
He also refined the binary number system, which is
at the foundation of virtually all digital computers.

13. Joseph Marie Charles, nicknamed Jacquard
(1752– 1834, played an important role in the
development of the earliest programmable loom
(the "Jacquard loom"), which in turn played an
important role in the development of other
programmable machines, such as computers.
• This portrait of Jacquard was woven in silk on a
Jacquard loom and required 24,000 punched cards
to create (1839).
• It was only produced to order.
• Charles Babbage owned one of these portraits ; it
inspired him in using perforated cards in his
analytical engine

14. Charles Xavier Thomas de Colmar (1785–1870) was a French
inventor and entrepreneur best known for designing, patenting
and manufacturing the first commercially successful mechanical
calculator, the Arithmometer.
The device was manufactured from 1851 to 1915 - there were
about 5,000 machines built during that time
Eventually about twenty European companies built clones of the
Arithmometer until the beginning of World War II.

15. Charles Babbage (1791 – 1871)
was an English mathematician
and is recognized today as the
Father of Computers because
his impressive designs for the
Difference Engine and
Analytical Engine foreshadowed
the invention of the modern
electronic digital computer.

16. The Difference Engine was
never fully built. Babbage
drew up the blueprints for it
while still an undergrad at
Cambridge University in
England.
But while it was in process of
being manufactured, he got a
better idea and left this work
unfinished in favor of the
Analytical Engine illustrated
on the next slide.
The
Difference
Engine

17. The Analytical Engine was
eventually built completely in the
latter half of the 19th
century, by
Georg and Edvard Schuetz as per
Babbage’s blueprints.
Film footage exists of the
machine in operation, and it is
truly a sight to behold, a
testament not only to Babbage’s
genius, but also to the
manufacturing prowess of the
The Analytical Engine incorporated an
arithmetical unit, control flow in the form of
conditional branching and loops, and integrated
memory, making it the first Turing-complete
design for a general-purpose computer.

18. Lady Augusta Ada, Countess of Lovelace
(1815 – 1856), was a mathematician who
helped Babbage in his work.
Above all, she documented his work, which
Babbage never could bother to do. As a
result we know about Babbage at all.
Lady Augusta Ada also wrote programs to
be run on Babbage’s machines, what made
her the first computer programmer.

19. Electro-mechanical
computers

20. Hermann Hollerith (1860 – 1920) worked as a statistician
for the U.S. Census Bureau in the 1880s and 1890s.
The 1880 census took seven years to be processed.
Hollerith deduced that the next census would take longer
than ten years.
So, as the saying goes, “necessity became the mother of
invention” and Hollerith designed and built the Census
Counting Machine illustrated in the next slide.

21. Punched cards (a la Jacquard looms) were
used to collect the census data (the origin of
the IBM punched cards) and the cards were
fed into a sorting machine before being read
by the census counting machine which
recorded and tabulated the results.
The 1890 census took just three months to
process even though quite a bit more data
was collected than ever before.

22. Hollerith’s company, the Tabulating
Machine Company, became the
Computer Tabulating Recording
Company in 1913 after merging with
another company that produced a
similar product.
1917: CTRC starts operations in Brazil;
the first big project was the 1920
census
In 1924, the company was renamed
International Business Machines (IBM)

23. Konrad Zuse and the Z3
• The Z3 was an electromechanical computer
designed by Konrad Zuse (1910-1995) , a
German scientist.
• The Z3 was one of the first machines that
could be considered a complete computing
machine. Program code and data were stored
on punched 35 mm film.
• The Z3 was completed in Berlin in 1941. The
German Aircraft Research Institute used it to
perform statistical analyses of wing flutter;
the machine was destroyed in 1943 during
an Allied bombardment.
• Zuse asked the German government for
money to develop a new machine, but
funding was denied, since such development
was deemed "not war-important"

24. While being a professor of Physics at Harvard, Howard Aiken (1900 – 1973) was
supported by IBM to build the ASCC computer (Automatic Sequence Controlled
Calculator), aka Harvard Mark I.
The computer had mechanical relays (switches) which flip-flopped back and forth to
represent mathematical data. It was huge, weighting some 35 tons with 500 miles of
wiring.

25. Rear Admiral Grace Murray
Hopper (1906 –1992) was an
American computer scientist and
United States Navy officer.
A pioneer in the field, she was one
of the first computer
programmers, and developed the
first compiler for a computer
programming language.
She conceptualized the idea of
machine-independent
programming languages, which
led to the development of COBOL.

26. One day, the program Dr. Hopper was running gave incorrect results
and, upon examination, a moth was found blocking one of the
relays. The bug was removed and the program performed to
perfection. Since then, a program error in a computer has been
called a bug

27. From the electro-
mechanical computers to
mainframes

28. The vacuum tube
In electronics, a vacuum tube ("tube" or "valve") is a
device that can be used to replace electromechanical
relays, because it is faster
Valves made electronic computing possible for the
first time, but the cost and relatively short Mean Time
Between Failure (MBTF) of valves were limiting
factors in the 1930s.
Later work confirmed that tube unreliability was not as
serious an issue as generally believed; the 1946
ENIAC, with over 17,000 tubes, had a tube failure
(which took 15 minutes to locate and fix) on average
every two days.

29. Alan Mathison Turing (1912 – 1954),
was an English mathematician,
cryptographer and computer scientist.
He was highly influential in the
development of computer science,
providing a formalization of the concepts
of "algorithm" and "computation" with
the Turing machine, which played a
significant role in the creation of the
modern computer.
Turing is widely considered to be the
father of computer science and artificial
intelligence.

30. During WWII Turing made a major contribution to
the development of a sophisticated computing
machine called Colossus which was used to help
crack the codes of the German Enigma Machine.
The Enigma machine was an electro-mechanical
machine used for the encryption and decryption of
secret messages, widely used for the Germans in
the war.
Turing’s work helped Allied codebreakers to
decrypt a vast number of messages that had been
enciphered using the Enigma. The intelligence
gleaned from this source was a substantial aid to
the Allied war effort.
The BBC broadcasted in 1991 the serie 'The dream
machine‘. You can know something more about
Turing and his work visiting
http://www.youtube.com/watch?
v=NbhbssXWDAE&feature=related
Germans working with the Enigma

31. The Colossus
Eleven Colossus
were built during
World War II (one
Mark 1, ten Mark
2) – the first
started running in
Feb 1944.
Colossus Mark 1 contained 1,500 electronic valves;
Colossus Mark 2 with 2,400 valves was both 5 times
faster and simpler to operate than Mark 1, greatly
speeding the decoding process.

32. Alan Turing: a tragic character
• Turing was an athlete: he achieved world-class Marathon standards - his best time was
only 11 minutes slower than the winner in the 1948 Olympic Games. In a 1948 cross-
country race he finished ahead of Tom Richards who won the silver medal in the Olympics.
• Turing's homosexuality resulted in a criminal prosecution in 1952, when homosexual acts
were still illegal in the United Kingdom. He accepted treatment with female hormones
(chemical castration) as an alternative to prison
• He died in 1954, several weeks before his 42nd birthday, from cyanide poisoning - an
inquest determined it was suicide. When his body was discovered an apple lay half-eaten
beside his bed, and although the apple was not tested for cyanide, it is speculated that
this was the mean by which a fatal dose was delivered.
• On 10 September 2009, following an Internet campaign, British Prime Minister Gordon
Brown made an official public apology on behalf of the British government for the way in
which Turing was treated after the war

33. The ENIAC: Electronic Numerical Integrator and Computer
This 1946 photograph
shows ENIAC , the first
general purpose
electronic computer,
housed at the
University of
Pennsylvania.
Developed in secret
starting in 1943, ENIAC
was designed to
calculate artillery firing
tables for the US Army.

34. The ENIAC: Electronic Numerical Integrator and Computer
When ENIAC was announced in 1946 it
was heralded in the press as a "Giant
Brain“ (in Brazil, “Cérebro Eletrônico”). It
boasted speeds one thousand times faster
than electro-mechanical machines.
The inventors of ENIAC promoted the
spread of the new technologies through a
series of lectures on the construction of
electronic digital computers at the
University of Pennsylvania in 1946, known
as the Moore School Lectures.

35. The ENIAC: Electronic Numerical Integrator and Computer
Besides its speed, the most remarkable thing
about ENIAC was its size and complexity.
ENIAC contained 17,468 valves, around 5
million hand-soldered joints. It weighed 30 ton.,
was roughly 2.4 m × 0.9 m × 30 m and took
up 167 m2
.
Input was possible from an IBM card reader,
and an IBM card punch was used for output.
These cards could be used to produce printed
output offline using an IBM accounting
machine, such as the IBM 405.
The task of programming was complex. After the program was figured out on paper,
the process of getting the program "into" the ENIAC by manipulating its switches and
cables took days. This was followed by a period of verification and debugging.
Programming the ENIAC

36. John von Neumann was a
mathematician working on the
hydrogen bomb project and became
aware of the ENIAC
Von Neumann came up with the bright
idea of using part of the ENIAC
internal memory (called Primary
Memory) to “store” the program inside
the computer and have the computer
go get the instructions from its own
memory - the stored program concept
was born!

37. Scandal!
ENIAC was conceived and designed by John Mauchly and J. Presper
Eckert of the University of Pennsylvania – they stole ideas from John
Vincent Atanasoff , from the Iowa State University and Clifford Berry.
Mauchly and Eckert successfully filed for the patent as inventors of the
electronic digital computer, ignoring Berry and Atanasoff’s work.
In 1972, this injustice was rectified when Honeywell (for Atanasoff)
successfully challenged Sperry Rand (the company that acquired
Eckert and Mauchly’s patent), and Atanasoff and Berry were credited
as being the inventors of the electronic digital computer.
- .

38. EDSAC
• The Electronic Delay Storage
Automatic Calculator (EDSAC)
was a UK made computer.
• The machine, having been
inspired by John von Neumann's
ideas was the first practical
stored-program electronic
computer.
• EDSAC ran its first program on
6 May 1949
• Later the project was supported by J. Lyons & Co. Ltd., a British restaurant-chain,
food manufacturing and hotel conglomerate founded in 1887, who were
rewarded with the first commercially applied computer, LEO I, based on the
EDSAC design.

39. The Transistor era
• The transistor is the fundamental
building block of modern electronic
devices, and is ubiquitous in modern
electronic systems. It replaced the valves
• Following its release in the early 1950s
the transistor revolutionized the field of
electronics, and paved the way for
smaller, faster and cheaper computers.
• John Bardeen, Walter Brattain, and
William Shockley (seated) working in
the laboratory where they built the first
transistor. Electronics magazine called
the device a "Crystal Triode."

40. What was the first thing that we
built with this miraculous new
technology?

41. A hearing aid ! ….1953
Zenith Royal-T
hearing aid - 3”
tall, 2.5” wide
A prehistoric iPod?

42. Followed
immediately
by the first
“pocket
radio” in
1954!

43. The TRADIC (for TRansistorized Airborne
DIgital Computer) was the first
transistorized computer, completed in 1954
The project initially examined the feasibility
of constructing a transistorized airborne
digital computer.
The TRADIC was small and light enough to
be installed in a B-52 Stratofortress

44. In the early 1950s, there were three main
computers makers
• UNIVAC
• Burroughs
• IBM

45. • March 1951: the Census Bureau
accepted delivery of the first
UNIVAC computer - Remington
Rand became the first American
manufacturers of a commercial
computer system
• Their first non-government
contract was for General Electric's
Appliance Park facility in Louisville,
Kentucky, who used the UNIVAC
computer for a payroll application.

46. Univac was used to forecast the 1952 presidential election (USA)
Polls gave the 1952 Presidential
election to Adlai Stevenson. UNIVAC,
star of CBS’ election coverage,
predicted an Eisenhower landslide.
UNIVAC was right.
The computer’s TV debut captivated
an audience already enthralled by
technology and confronting new
tools—and new terminology—
almost daily.

47. Computers in popular culture
“UNIVAC” became synonymous
with “computer” to the
American public in the 1950s.
This comic book combines
computerized matchmaking,
which began in the late 1950s,
with a popular television dating
show format

48. THE 2ND GENERATION COMPUTERS (from 1955)
• Programming languages such as FORTRAN (FORmula TRANslator) and
COBOL (COmmon Business Oriented Language) were developed at that
time
• Typical of that era were the IBM 1401 and Burroughs B200
• Smaller in size
• All transistorized
• Reliable
IBM 1401Burroughs B200

49. In 1957 the first computer
came to Brazil. It was a
Univac 120, purchased by
the State of Sao Paulo to
control the water supply
service in the capital.
We talked a lot about Univac, which was the first e bigger computer
manufacturer and no longer exists. You can guess why?
No planning, bad management!

50. In 1959 Anderson Clayton bought a IBM 305 RAMAC,
the first computer in the Brazilian private sector
IBM 305 RAMAC, announced 1956, was the first commercial computer that used a
moving head hard disk drive (5 MB, 1 ton) for secondary storage. RAMAC stood for
"Random Access Method of Accounting and Control".
RAMAC’s HD

51. In the 60's, the world was in the middle of
the space race. With that came the need
to build lightweight and powerful
computers that could be embedded in
rockets.
NASA has spent billions of dollars on its
space program in the hiring of
manufacturers of transistors to perform an
even more radical miniaturization.
Thus were created the first integrated
circuits, also called chips. Basically, a chip
is an electronic component comprising
hundreds or thousands of transistors.
This led to the third generation of
computers

52. Example of this time is the IBM 360,
sold between 1964 and 1978

53. Programming in the 1960’s and 1970’s
IBM programmer drawing a flowchart

54. Data entry at the time could be made with​​
punched paper tape (replacing the punched
cards)

55. Data were mainly stored in magnetic
tapes and disks, such as the IBM 2314
(1966, 30 mb)

56. From that point, mainframe
computers have evolved to the
point where they are today, even
using elements also used in
microcomputers

57. 57
Internal
Batteries
(optional)
Power
Supplies
3x
I/O
cages
Fiber Quick Connect
(FQC) Feature
(optional)
2 x Support
Elements
Processor Books,
Memory, MBA and
HCA cards
2 x Cooling
Units
InfiniBand I/O
Interconnects
FICON &
ESCON
FQC
Ethernet cables for
internal System
LAN connecting
Flexible Service
Processor (FSP)
cage controller
cards
z10 EC – Under the covers (Model E56 or E64)

58. Evolution!

59. And to avoid this...

60. Prof. Dr. Vivaldo José Breternitz
Acad. Marta D. Magalhães Santos
Prof. Esp. Elisabete Panssonatto Breternitz
Os autores agradecem seus comentários
através do vjbreternitz@mackenzie.br

61. vjbreternitz@mackenzie.br