A computer is a general purpose device that can be programmed to carry out arithmetic and logical operations. It consists of at least one processing element and some form of memory. The processing element performs operations and is controlled by a sequencing unit that can change the order of operations based on stored information. Peripheral devices allow information to be retrieved from an external source and results saved. A computer's processing unit executes instructions that make it read, manipulate, and store data, with conditional instructions changing the sequence as a function of the machine's state. Programmers developed user interfaces to accept human input and return results for human consumption.
2. A computer is a general purpose device which can be programmed to
carry out a finite set of arithmetic or logical operations. Since a
sequence of operations can be readily changed, the computer can solve
more than one kind of problem. Conventionally, a computer consists of
at least one processing element and some form of memory. The
processing element carries out arithmetic and logic operations, and a
sequencing and control unit that can change the order of operations
based on stored information. Peripheral devices allow information to
be retrieved from an external source, and the result of operations
saved.
A computer's processing unit executes a series of instructions that
make it read, manipulate and then store data. Conditional instructions
change the sequence of instructions as a function of the current state of
the machine or its environment.
In order to interact with such a machine, programmers and engineers
developed the concept of a user interface in order to accept input from
humans and return results for human consumption.
3. ON THE BASIS OF
DATA HANDLING
PURPOSE
SIZE
APPLICATION
GENERATION/TECHNOLOGY
4. ANALOG COMPUTER
A form of computer that uses continuous physical phenomena such as
electrical, mechanical, or hydraulic quantities to model the problem
being solved.
They solve problem by translating physical conditions such as flow,
temperature, pressure, angular position or voltage into related
mechanical or electrical related circuits. speedometer
DIGITAL COMPUTER
A computer that performs calculations and logical operations with
quantities, numerical or otherwise, represented as digits, usually in the
binary number system
Digital computer represents physical quantities with the help of digits
or numbers.
HYBRID COMPUTER Digital watch
A combination of computers those are capable of inputting and
outputting in both digital and analog signals. A hybrid computer
system setup offers a cost effective method of performing complex
simulations.
The hybrid system provides the good precision that can be attained
with analog computers and the greater control that is possible with
digital computers, plus the ability to accept the input data in either
form.
ECG machine
5. 1. General Purpose Computers
General purpose computers are designed to solve a large variety
of problems. The different programs can be used to solve many
problems. Most digital computers are general purpose computers
and used in business and commercial data processing.
2. Special Purpose Computers
A computer designed for machine control or process control
would be different than a general purpose computer. The special
purpose computers are designed to solve specific problems. The
computer program for solving a specific problem is built right
into the computer. Most analog computers are special purpose
computers. These special purpose computers are widely used in
industrial robotics.
6. First Generation (vacuum tubes)
Second Generation (transistors)
Third Generation (integrated circuits)
Fourth Generation (microprocessors)
Fifth Generation (artificial intelligence)
7. The first generation of computers started
with the UNIVAC I (Universal Automatic
Computer) built by Mauchly and Eckert.
It was sold to the U.S. Census Bureau.
This machine was dedicated to business
data processing and not military or
scientific purposes.
The first computers used vacuum tubes
for circuitry and magnetic drums for
memory, and were often
enormous, taking up entire rooms.
They were very expensive to operate and
in addition to using a great deal of
electricity, generated a lot of heat, which
was often the cause of malfunctions.
First generation computers relied on
machine language, the lowest-level
programming language understood by
computers, to perform operations, and
they could only solve one problem at a
time. Input was based on punched cards
and paper tape, and output was
displayed on printouts.
UNIVAC 1
8. Use of transistors for internal operations: tiny
solid state transistors replace vacuum tubes in
computers.
Magnetic core as primary internal-storage
medium: Electric currents pass through wires
which magnetize the core to represent on and off
states .Data in the cores can be found and
retrieved for processing in a few millionths of a
second.
Increased main-storage capacity: The internal
or main storage was supplemented by use of
magnetic tapes for external storage. These tapes
substituted for punched cards or paper.
High-level programming
languages (COBOL,FORTRAN) : These
languages resembled English. FORTRAN
(FORmula TRANslator) was the first high-level
language that was accepted widely. This language
was used mostly for scientific applications.
COBOL (Common Business-Oriented Language)
was developed in 1961 for business data
processing. Its main features include: file-
processing, editing, and input/output
capabilities.
9. The development of the integrated circuit was
the hallmark of the third generation of
computers.
Instead of punched cards and printouts, users
interacted with third generation computers
through keyboards and monitors and
interfaced with an operating system.
Computers for the first time became accessible
to a mass audience because they were smaller
and cheaper than their predecessors.
Extensive use of high-level programming
languages: The software industry evolved
during this time.
Remote processing and time-
sharing through communication: Computers
were then able to perform several operations at
the same time.
Applications such as airline reservation
systems, market forecasting, credit card
billing. Multitasking was also accomplished.
Both scientific and business applications could
be run on the same machine.
Examples: IBM System/360 NCR 395
Burroughs B6500
10. The microprocessor brought the fourth
generation of computers, as thousands of
integrated circuits were built onto a
single silicon chip.
The Intel 4004 chip, developed in 1971,
located all the components of the
computer-from the central processing
unit and memory to input/output
controls-on a single chip.
Microprocessors also moved out of the
realm of desktop computers and into
many areas of life as more and more
everyday products began to use
microprocessors.
As these small computers became more
powerful, they could be linked together
to form networks, which eventually led
to the development of the Internet.
Versatility of input/ output devices.
Increased storage capacity and speed.
Increased use of minicomputers
Applications: mathematical modelling
and simulation, electronic funds transfer,
computer-aided instruction and home
computers. Internet Explosion.
11. Fifth generation computing devices,
based on artificial intelligence, are
still in development, though there
are some applications, such as voice
recognition, that are being used
today.
The use of parallel processing and
superconductors is helping to make
artificial intelligence a reality.
Quantum computation and
molecular and nanotechnology will
radically change the face of
computers in years to come.
The goal of fifth-generation
computing is to develop devices that
respond to natural language input
and are capable of learning and self-
organization.
12. Until recently computers were classified as :
Supercomputers
Main-Frame computers
Mini computers
Micro computers
Computer
↓---------------------↓----------------------↓
Analog Digital Hybrid
↓
1.Super Computers
2.Mainframe Computers
3.Mini Computers
4.Micro Computers
13. • Supercomputers are the fastest
computers available at any given
time and are normally used to solve
problems, which require intensive
numerical computations. They are
also very large in size.
• Examples of such problems are
weather forecasting, fluid dynamics,
nuclear simulations, animated
graphics, theoretical astrophysics,
and complex scientific
computations.
• These computers are extremely
expensive and the speed is measured
in billions of instructions per
seconds/floating point operations
per second or FLOPS.
• In terms of computational
capability, memory size and speed,
supercomputers are the most
powerful, are very expensive, and
not cost-effective just to perform
batch or transaction processing.
14. Supercomputers are built by
interconnecting thousands of processors
that can work in parallel.
Some examples of supercomputers are
IBM Roadrunner, IBM Blue gene and
Intel ASCI red.
PARAM is a series of supercomputer
assembled in India by C-DAC (Center for
Development of Advanced
Computing), in Pune. PARAM Padma is
the latest machine in this series. The
peak computing power of PARAM
Padma is 1 Tera FLOP (TFLOP).
• Drawbacks:
1. Operating Supercomputer
requires highly qualified staff.
2. Experts are required for such
computer engineering.
3. They are sensitive to
temperature, humidity, dust, etc.
4. Non portability & large size.
15. Mainframes are the second largest (in capability
and size) of the computer family.
The term mainframe computer was created to
distinguish the traditional, large, institutional
computer intended to service multiple users from
the smaller, single user machines. These
computers are capable of handling and processing
very large amounts of data quickly.
In some ways, mainframes are more powerful
than supercomputers because they support more
simultaneous programs. But supercomputers can
execute a single program faster than a mainframe.
It consists of a high-end computer processor, with
related peripheral devices, capable of supporting
large volumes of data processing, high-
performance online transaction processing, and
extensive data storage and retrieval.
16. Mainframe computers are used in large
institutions such as government, banks and
large corporations. Its computational power is
measured in MIPS (Million instructions per
second) and responds up to 100s of million
users at one time.
They normally use proprietary operating
systems, which usually provide high expensive
services such as user accounting, file security
and control. They are also very much
expensive.
Some examples of the mainframe are IBM’s
ES000, VAX 8000 and CDC 6600.
The chief difference between a supercomputer
and a mainframe is that a supercomputer
channels all its power into executing a few
programs as fast as possible, whereas a
mainframe uses its power to execute many
programs concurrently.
Drawbacks: same as those mentioned in
supercomputers.
17. Lies in between mainframe computers and
the microcomputers or personal computers.
Their speeds are rated between one and fifty
million instructions per second (MIPS).
They have primary storage in hundred to
three hundred megabytes range with direct
access storage device.
In general, a minicomputer is a
multiprocessing system capable of
supporting from 4 to about 200 users
simultaneously.
It serves as a centralized storehouse for a
cluster of workstations or as a network
server.
These are used in interactive applications in
industries, research organizations, colleges
and universities. They are also used for real-
time controls and engineering design work.
Disadvantages
Cannot connect all hardware devices
Cannot execute all languages and softwares.
18. Microcomputers are the most
common type of computers used
by people today.
These are the smallest range of
computers. They were introduced
in the early 70’s having less
storing space and processing
speed. The term “microcomputer”
was introduced with the advent of
single chip microprocessors. The
term "microcomputer" itself is
now practically an anachronism.
Microcomputers are small, low-
cost and single-user digital
computer. They consist of CPU,
input unit, output unit, storage
unit and the software.
Can be connected together to
create a network of computers IBM_PC-AT microcomputer
20. In most common use, server is a
physical computer (a computer
hardware system) dedicated to running
one or more such services (as a host), to
serve the needs of users of the other
computers on the network.
Depending on the computing service
that it offers it could be a database
server, file server, mail server, print
server, web server, gaming server, or
some other kind of server.
In the context of client-server
architecture, a server is a computer
program running to serve the requests of
other programs, the "clients". Thus, the
"server" performs some computational
task on behalf of "clients". The clients
either run on the same computer or
connect through the network.
21. A workstation is a high-end
microcomputer designed for technical or scientific
applications.
Both being microcomputers, workstations had
offered higher performance than desktop
computers, especially with respect
to CPU and graphics, memory capacity, and
multitasking capability.
They are optimized for the visualization and
manipulation of different types of complex data.
A workstation class PC may have some of the
following features:
support for ECC memory
a larger number of memory sockets which use
registered (buffered) modules
multiple processor sockets, powerful CPUs (for
Intel CPU it will be server derived Xeon instead of
typical for PCs Core)
multiple displays
run reliable operating system with advanced SGI Octane workstation
features
high performance graphics card
22. Embedded computers are
computers that are a part of a
machine or device.
Embedded computers
generally execute
a program that is stored
in non-volatile memory and
is only intended to operate a
specific machine or device.
Typically required to operate
continuously without being
reset or rebooted.
Software usually cannot be
BLU-RAY PLAYER
modified.
23. Alan Turing is widely regarded as the father of modern computer science.
In 1936 Turing provided an influential formalisation of the concept of the Alan Turing
algorithm and computation with the Turing machine, providing a blueprint
for the electronic digital computer.
25. 1949- Manchester mark 1
1951- UNIVAC
1951- Ferranti mark 1
1952- IBM mainframe computer
1954- Fortran
Early 1960s- IBM 1401
1964- IBM 360
1967- floppy disks
1969- UNIX
1970- RAM
1970- 1st dot matrix printer
1970- mouse invented
1971- 1st video game console
1972- Public demo of ARPANET
1974- Altair 8800
1974- Telnet is introduced
26. 1975- Microsoft formed
1976- Apple 1 computer-1976
1981- MS-DOS 1.0 released
1981- Osborne 1
1982- CD invented
1983- Microsoft windows announced
1984- 3.5 inch floppy disc introduced
1986- The AT or 101 key keyboard is introduced by IBM
1990- The first search engine Archie
1991- Internet opened for commercial use
1991- Linux is introduced
1993- Intel releases the Pentium Processor
1995- The first VoIP software (Vocaltec) is released
1995- Microsoft releases Internet Explorer 1.0
1997- IEEE releases 802.11 (Wi-Fi) standard
27. The first computers were designed by
Charles Babbage in the mid-1800s, and
are sometimes collectively known as the
Babbage Engines.
These early computers were never
completed during Babbage’s lifetime, but
their complete designs were preserved.
Eventually, one was built in 2002.
While these early mechanical computers
bore little resemblance to the computers
in use today, they paved the way for a
number of technologies that are used by
modern computers, or were instrumental
in their development.
Other important mechanical computers
are the Automatic Electrical Tabulating
Machine—which was used in the U.S.
Census of 1890 to handle data from more
than 62 million Americans—and the first
binary computer: Konrad Zuse’s Z1,
which was developed in 1938 and was the
precursor to the first electro-mechanical
computer.
28. Electro-mechanical computers generally
worked with relays and/or vacuum tubes,
which could be used as switches.
Some electro-mechanical computers—
such as the Differential Analyzer built in
1930—used purely mechanical internals
but employed electric motors to power
them.
These early electro-mechanical
computers were either analog or were
digital—such as the Model K and the
Complex Number Calculator, both
produced by George Stibitz.
Stibitz, by the way, was also responsible
for the first remote access computing,
done at a conference at Dartmouth
College in New Hampshire.
It was during the development of these
early electro-mechanical computers that
many of the technologies and concepts
still used today were first developed.
The Z3 developed by Konrad Zuse was
the first program-controlled digital
computer.
29. The first electronic computers were
developed during the World War II,
with the earliest of those being
the Colossus. It used vacuum tubes and
paper tape and could perform a number
of Boolean (e.g. true/false, yes/no)
logical operations.
Another notable early electronic
computer was nicknamed "The Baby"
(officially known as the Manchester
Small-Scale Experimental Machine).
While the computer itself wasn’t
remarkable—it was the first computer
to use the Williams Tube, a type of
random access memory (RAM) that
used a cathode-ray tube.
Some early electronic computers used
decimal numeric systems (such as the
ENIAC and the Harvard Mark 1), while
others—like the Atanasoff-Berry
Computer and the Colossus Mark 2—
used binary systems.
30. The first commercially available computers came in the 1950s. While
computing up until this time had mainly focused on scientific,
mathematical, and defence capabilities, new computers were designed
for business functions, such as banking and accounting.
In 1951, LEO (Lyons Electronic Office) became the first computer to
run a regular routine office job.
The UNIVAC was the first commercial computer developed in the U.S.,
with its first unit delivered to the U.S. Census Bureau. It was the first
mass-produced computer, with more than 45 units eventually
produced and sold.
The IBM 701 was another notable development in early commercial
computing; it was the first mainframe computer produced by IBM. It
was around the same time that the Fortran programming
language was being developed (for the 704).
A smaller IBM 650 was developed in the mid-1950s, and was popular
due to its smaller size and footprint (it still weighed over 900kg, with a
separate 1350kg power supply).
31. The development of transistors
led to the replacement of
vacuum tubes, and resulted in
significantly smaller computers.
In the beginning, they were less
reliable than the vacuum tubes
they replaced, but they also
consumed significantly less
power.
These transistors also led to
developments in computer
peripherals. The first disk
drive, the IBM 350 RAMAC, was
the first of these introduced in
1956. Remote terminals also
became more common with
these second-generation
computers.
32. The microchip (or integrated circuit) is
one of the most important advances in
computing technology.
The microchip spurred the production of
minicomputers and microcomputers,
which were small and inexpensive
enough for small businesses and even
individuals to own. The microchip also
led to the microprocessor, another
breakthrough technology that was
important in the development of the
personal computer.
There were three microprocessor designs
that came out at about the same time.
The first was produced by Intel (the
4004). Soon after, models from Texas
Instruments (the TMS 1000) and Garret
AiResearch (the Central Air Data
Computer, or CADC) followed.
The first processors were 4-bit, but 8-bit
models quickly followed by 1972.
33. The first personal computers were built in the
early 1970s. Most of these were limited-production
runs, and worked based on small-scale integrated
circuits and multi-chip CPUs.
The Altair 8800 was the first popular computer
using a single-chip microprocessor.
Clones of this machine quickly cropped up, and
soon there was an entire market based on the
design and architecture of the 8800. It also
spawned a club based around hobbyist computer
builders, the Homebrew Computer Club.
1977 saw the rise of the "Trinity" (based on a
reference in Byte magazine): the Commodore PET,
the Apple II, and the Tandy Corporation’s TRS-80.
These three computer models eventually went on
to sell millions.
These early PCs had between 4kB and 48kB of
RAM. The Apple II was the only one with a full-
colour, graphics-capable display, and eventually
Altair 8800
became the best-seller among the trinity, with
more than 4 million units sold.
34. One particularly notable development in the
1980s was the advent of the commercially
available portable computer.
The first of these was the Osborne 1, in 1981.
It had a tiny 5" monitor and was large and
heavy compared to modern laptops
(weighing in at 23.5 pounds). Portable
computers continued to develop, though,
and eventually became streamlined and
easily portable, as the notebooks we have
today are.
The first portable computer that was actually
marketed as a "laptop" was the Gavilan SC in
1983.
Early models had monochrome displays,
though there were colour displays available
starting in 1984 (the Commodore SX-64).
Laptops grew in popularity as they became
smaller and lighter. By 1988, displays had
reached VGA resolution, and by 1993 they Gavilan SC
had 256-color screens. Other hardware
features added during the 1990s and early
2000s included high-capacity hard drives and
optical drives.
35. Mobile computing is one of the most recent
major milestones in the history of computers.
Many smartphones today have higher processor
speeds and more memory than desktop PCs had
even ten years ago.
Mobile computing really got its start in the
1980s, with the pocket PCs of the era. These were
something like a cross between a calculator, a
small home computer and a PDA. They largely
fell out of favour by the 1990s. During the 1990s,
PDAs (Personal Digital Assistant) became
popular.
A number of manufacturers had models,
including Apple and Palm. The main feature
PDAs had that not all pocket PCs had was a
touchscreen interface. PDAs are still
manufactured and used today, though they’ve
largely been replaced by smartphones.
Smartphones have truly revolutionized mobile
computing. Most basic computing functions can
now be done on a smartphone, such as email,
browsing the internet, and uploading photos
and videos.
36. Another recent progression in
computing history is the development of
netbook computers. Netbooks are
smaller and more portable than standard
laptops, while still being capable of
performing most functions average
computer users need (using the Internet,
managing email, and using basic office
programs). Some netbooks go as far as to
have not only built-in Wi-Fi capabilities,
but also built-in mobile broadband
connectivity options.
The first mass-produced netbook was
the Asus Eee PC 700, released in 2007.
Another important development was the
evolution of multicore processors. Intel
released the Pentium D, their first dual-
core 64-bit desktop processor in mid
2005. AMD followed suite by releasing
the Athlon 64 X2, their first dual-core
64-bit desktop processor. Later quad-
and hexa- core processors also arrived.