1. History of Computers
and its Types

2. Reedy (1984) quoted Aldous Huxley
thus:
‚that men do not learn very much
from the lessons of history is the
most important of all the lessons
that history has to teach.‛
This therefore emphasizes the
need to study history of the

3. What is a Computer?

4. A computer is any device which aids
humans in performing various kinds
of computations or calculations.
In that respect the earliest
computer was the abacus, used to
perform basic arithmetic
operations.
Every computer supports some form
of input, processing, and output.
We input information, the computer
processes it according to its basic

5. Introduction
The word ‘computer’ is an old word
that has changed its meaning several
times in the last few centuries.
The American Heritage Dictionary (1980) gives its first computer
definition as “a person who computes.”
Webster’s Dictionary (1980) defines it as “a programmable electronic
device that can store, retrieve, and process data”

6. Devices that comprise a
Computer
system Monitor Speaker
(output) (output) System unit
(processor, memory…)
Printer
(output)
Storage devices
(CD-RW, Floppy,
Hard disk, zip,…)
Mouse
(input)
Scanner Keyboard
(input) (input)
6

7. Computers can perform four general
operations, which comprise the
information processing cycle.
Input
Process
Output
Storage 7

8. Computers can be classified according to their CAPACITY
Volume of work or the data
processing capability a computer can
handle.
PERFORMANCE
Data that can be Amount and type of
Speed of software
stored in memory Number and type
internal available for use
of peripheral
operation
devices

9. Modern computers do this electronically, which
enables them to perform a vastly greater number of
calculations or computations in less time.
Graphics, sound etc. are merely abstractions of the
numbers being crunched within the machine; in
digital computers these are the ones and zeros,
representing electrical on and off states, and endless
combinations of those.
In other words every image, every sound, and every
word have a corresponding binary code.

10. HISTORY
Konrad Zuse John Mauchly & J Eckert Sir Frederick Williams & Tom Kilburn
Inventor of Modern Computer EINAC William Kilburn Tube - RAM
1939 1942 1946 1948 XXX XXX
John von Newman Dr Eckert & John Mauchly
John Atanasoff
EINAC Modified UNIVAC
Digital Computer

11. HISTORY OF
COMPUTERS
 First electronic computers used vacuum  The second generation of computers
tubes, and they were huge and complex. came about thanks to the invention
of the transistor, which then started
 The first general purpose electronic replacing vacuum tubes in computer
design.
computer was the ENIAC (Electronic
Numerical Integrator And Computer).
 The first transistor computer was
created at the University of
 It was programmed using plugboards and Manchester in 1953
switches, supporting input from an IBM
card reader, and output to an IBM card
 IBM also created the first disk drive
punch.
in 1956, the IBM 350 RAMAC
 It took up 167 square meters, weighed 27
tons, and consuming 150 kilowatts of
 Transistor computers consumed far
power. It used thousands of vacuum tubes, less power, produced far less heat,
crystal diodes, relays, resistors, and and were much smaller compared to
capacitors. the first generation, albeit still big by
today’s standards.

12. First generation
computers

13. Second generation
computer

14. Third Fourth
Generation Generation
Computers (1960) Computers (1971)
 The invention of the integrated circuits  First microchips-based central
(ICs), also known as microchips, paved processing units consisted of multiple
the way for computers as we know them microchips for different CPU
today. components.
 Making circuits out of single pieces of
silicon, which is a semiconductor,  The drive for ever greater integration and
allowed them to be much smaller and miniaturization led towards single-chip
more practical to produce. CPUs, where all of the necessary CPU
 This also started the ongoing process of components were put onto a single
integrating an ever larger number of microchip, called a microprocessor.
transistors onto a single microchip.
 During the sixties microchips started  The first single-chip CPU, or a
making their way into computers, but microprocessor, was Intel 4004.
the process was gradual, and second
generation of computers still held on.
 The advent of the microprocessor
 Minicomputers can be seen as a bridge
between mainframes and spawned the evolution of the
microcomputers, which came later as the microcomputers, the kind that would
proliferation of microchips in computers eventually become personal computers
grew. that we are familiar with today.

15. 3rd generation
computer

16. 4th generation
computer

17. First Generation of
Microcomputers (1971 – 1976)
 First microcomputers often came in kits, and many were just boxes with
lights and switches, usable only to engineers and hobbyists who could
understand binary code.
 Some, however, did come with a keyboard and/or a monitor, bearing
somewhat more resemblance to modern computers.
 The reason some might consider it a first microcomputer is because it
could be used as a de-facto standalone computer, it was small enough,
and its multi-chip CPU architecture actually became a basis for the x86
architecture later used in IBM PC and its descendants.
 However, if we are looking for the first microcomputer that came with a
proper microprocessor, was meant to be a standalone computer, and
didn’t come as a kit then it would be Micral N, which used Intel 8008
microprocessor.

18. 1st generation
microcomputer

19. Second Generation
Microcomputers (1977)
 As microcomputers continued to evolve they became easier to
operate, making them accessible to a larger audience.
 They typically came with a keyboard and a monitor, or could be
easily connected to a TV, and they supported visual
representation of text and numbers on the screen.
 Famous early examples of such computers include Commodore
PET, Apple II, and in the 80s the IBM PC.
 The nature of the underlying electronic components didn’t
change between these computers and modern computers we
know of today, but what changed was the number of circuits that
could be put onto a single microchip.
 Intel’s co-founder Gordon Moore predicted the doubling of
the number of transistor on a single chip every two years, which
became known as “Moore’s Law”, and this trend has roughly
held for over 30 years .

20. 2nd generation
computer

21. Types of
computers

22. Portable Computers



″




23. MINICOMPUTERS
 In the 1960s, the growing demand for a smaller stand-alone
machine brought about the manufacture of the minicomputer
 Minicomputer systems provide faster operating speeds and
larger storage capacities than microcomputer systems
 Operating systems developed for minicomputer systems
generally support both multiprogramming and virtual storage.
 5Minicomputers usually have from 8k to 256k memory
storage
 The PDP-8, the IBM systems 3 and the Honeywell 200 and 1200
computer are typical examples of minicomputers.

24. MEDIUM-SIZE COMPUTERS
 Medium-size computer systems provide faster
operating speeds and larger storage capacities.
 They can support a large number of high-speed
input/output devices and several disk drives.
 Medium-size computer can support a management
information system.
 IBM System 370, Burroughs 3500 System and NCR
Century 200 system are examples of medium-size
computers.
 They usually have memory sizes ranging from 32k to
512k.

25. LARGE COMPUTERS
 Large computers are next to Super Computers and
have bigger capacity than the Mediumsize computers.
 Large computers have storage capacities from 512k to
8192k.
 Expandability to 8 or even 16 million characters is
possible with some of these systems.
 They are used in complex modeling, or simulation,
business
 Operations, product testing, design and engineering
work and in the development of space technology.

26. SUPERCOMPUTERS
The supercomputers are the biggest and fastest
machines today
These machines are applied in nuclear weapon
development, accurate weather forecasting and as host
processors for local computer
Super computers have capabilities far beyond even the
traditional large-scale systems
Supercomputers may need the assistance of a
medium-size general purpose machines (usually called
front-end processor) to handle minor programs or
perform slower speed or smaller volume operation.

27. Classification by their basic
perating PRINCIPLE
ANALOG DIGITAL HYBRID
COMPUTERS COMPUTERS COMPUTERS

28. ANALOG COMPUTERS
Analog computers were well known in the 1940s they
are now uncommon.
In such machines, numbers to be used in some
calculation were represented by physical quantities
such as electrical voltages.
The computing units of analog computers respond
immediately to the changes which they detect in the
input variables.
Analog computers excel in solving differential
equations and are faster than digital computers.

29. DIGITAL COMPUTERS
Most computers today are digital. They represent
information discretely and use a binary system.
The Pocket Webster School & Office Dictionary
(1990) simply defines Digital computers as “a
computer using numbers in calculating.”
They process data in numerical form and their circuits
perform directly the mathematical operations of
addition, subtraction, multiplication and division.
Digital information is discrete, it can be copied
exactly but it is difficult to make exact copies of analog
information.

30. HYBRID COMPUTERS
These are machines that can work as both analog
and digital computers.

31. WHAT HAPPENS WHEN GREAT
MINDS COME TOGETHER?

32. Bill Gates
Inspiring the era of the home computer
Commercialising the operating system
Launching Windows 95
Evolution of microsoft

33. Steve jobs

34. Apple I, 1976
Apple Computer was founded on April
1, 1976 by a small group headed by
Jobs, engineer Steve Wozniak and
industry vet Ronald Wayne

35. Apple II, 1977
The company hit the jackpot one
year later with 1977's Apple II, a fully
assembled desktop computer in a
handsome case.
Hackers still took to it because of its
expandability.
 Schools used it to teach
programming (it ran Integer BASIC)
and offices started snatching them
up once VisiCalc launched on the
nascent platform.

36. Macintosh, 1984
The Macintosh arrived in 1984, and it was
the first computer to successfully
integrate two things that are now
commonplace: a graphical user interface
and a mouse.
 Little pictures of folders, the piece of
paper denoting a file, the trash can —
most of us learned how all of these things
worked when we sat down at the Mac.
Apple launched the Macintosh with a
massive media campaign spearheaded
by a minute-long TV commercial (riffing
on Orwell's 1984) that aired during the
Super Bowl.

37. Apple IIc,
1984 the Apple IIc, a slimmed-down version
 Apple released
of the Apple II that was much more portable.
 It had a handle on the back so you could carry it
around comfortably with one hand. It wasn't quite a
laptop — the monitor and power supply weren't
attached — and the guts weren't a whole lot different
than what you got in the bigger Apple II models.
 It was one of the first small-form-factor PCs to hit the
market, signaling the industry-wide move toward
compact.
 It was an era when computers beginning to creep into
middle-class homes, and first-time buyers found the IIc
a "friendly" and appealing option.
 It looked equally attractive in the family room as it
did in the office.


38. Apple IIc, 1984

39. LaserWriter, 1985
 The LaserWriter wasn't the first
desktop laser printer to hit the market,
but it was the first created for the
Macintosh, and the first to use the
cutting-edge PostScript language
 It was announced on the same day as
its killer app, Aldus PageMaker.
 the LaserWriter wasn't the first shot
fired in the desktop publishing
revolution, it was the first to draw
blood as it costs $7,000.

40. LaserWriter,
1985

41. Pixar, 1986
 Steve Jobs bought Pixar in 1986.Jobs paid $5 million to
George Lucas and sank $5 million of his own money into
the company.
 His original vision for Pixar was to develop graphics-
rendering hardware and software, but the business
eventually evolved into an animation studio.
 Jobs signed a distribution deal with Disney and Pixar
began cranking out a string of hit family films, all of
them computer-animated. 1995's Toy Story was the first
blockbuster. Toy Story 2, Monsters, Inc., Finding
Nemo, The Incredibles, Cars, WALL-E and Upfollowed.
Accolades and Oscars came rolling in, along with massive
mountains of cash.
 In 2006, Jobs flipped his original $10 million investment,
selling Pixar to Disney for $7.4 billion in stock.

42. Pixar,
1986

43. NeXT, 1988
 After the success of the Macintosh, Jobs was
marginalized by Apple's board of directors, so he left
to found a new computer company called NeXT.
 Jobs launched a new computer system at NeXT. Its
most famous workstation was an austere black cube
that cost $6,500. It ran a new operating system,
NeXTSTEP, which was based on Unix.
 It was fast and especially adept at math functions,
and it had a built-in Ethernet port in an age when
most computers still needed a network interface card.
 Tim Berners-Lee used one to write the first web server
and the first web browser.
 The first server node on the World Wide Web was a
NeXT box.

44. NeXT, 1988

45. iMac, 1998
After NeXT failed to gain traction, Jobs sold the
company to Apple and came back into the fold in 1996.
Two years later, the company released a complete
rewrite of the desktop PC — the candy-colored iMac.
The first iMac was a runaway hit, and the all-in-one
design is still used by today's iMac (and widely copied
by other PC manufacturers).

46. iMac, 1998

47. Power Mac G4 Cube, 2000
Jobs wasn't ready to let go of his dream of
a cube-shaped computer, which he first
tried at NeXT.
He encouraged Apple designer Jonathan
Ive to work the shape into the Power Mac
line, and the company pumped out the
eight-inch clear acrylic cube in 2000.
It didn't do so hot. It was $1,800, the disk
drive had problems, and the case
developed stress cracks easily.

48. Power Mac G4 Cube,
2000

49. iPod, 2001
The first iPod was a $400 MP3 player with a 5-
gigabyte hard drive and a mechanical scroll
wheel that didn't sync to Windows machines.
The iPod's all-white design was minimalist
compared to other players that came before
and, more importantly, the user interface was
remarkably easy for anyone who picked it up
to figure out.
The hardware had its quirks — if you got sand
in the scroll wheel, you'd get stuck listening to
Spin Doctors all day the touch-wheel, a color
screen for watching videos and eventually, the
industry-standard touchscreen.

50. iPod, 2001

52. BY:-SALMA.K
SAEEL.D
BINALI.K
SAGAR.K
JYOTSNA.S
HITEN.S