1. Brief History of Computers
HASEEB AHMAD KHAN
Sarhad University of Science & Information Technology Peshawar
2. History of Computer
The five generations of computers are:
First generation electronic computers(1942-1955)
Second generation (1955-1964)
Third generation (1964-1975)
Forth generation (1975-onwards)
Fifth generation
3. The Dark Ages (5000 BC 1890 AD)
Abacus (5000 BC)
As computer is primarily used for calculating purposes and so as ABACUS therefore computer professionals relate
computer with this manual calculating device. Structurally, it consists of frame with beads strung on wire or rods.
It was used to perform simple addition and subtraction can be carried out rapidly and efficiently by positioning the beads
appropriately. It consists of wooden beads and calculation were performed by moving these beads properly.
Four different types of ABACUS were:
1. Roman ABACUS
2. The Chinese Swanpan.
3. The Japanese Soroban
4. Russian Schotty.
NAPIER’S BONES (1617……………17th century)
It was a cupboard multiplication calculator invented by john Napier.
John Napier invented Napier Bone for calculation of logarithmic values.
It was used to perform difficult multiplication operations to simple addition of entries in a table
Another manual calculating device was napier’s bones (or Cardboard multiplication calculator) developed by john Napier, a scottish
mathematician. It consists of a set of eleven rods with numbers marked on them in such a way that by simply placing the roads side-by-side
products and quotients of large numbers can be obtained.
4. Pascaline or Pascal Calculator (17th century)
It was invented by Blaise Pascal.
It was first mechanical adding machine
It had a series of wheels with teeth which could be turned
using hands.
5. JACQUARD’S LOOM (1801)
Punched cards
Joseph Marie jacquard, a French textile manufacturer, invented the first punched cards machine. This machine
was designed for automatically creating weaving patterns on cloths.
They were able to read information that which have been punched
into the cards automatically
DIFFERENCE ENGINE (1822)
in 1822 Charles Babbage, a British scientist and mathematician at Cambridge University, invented a huge
mechanical machine called difference engine. It is based on the principle of difference of the squares of
number . Babbage is considered to the father for modern digital computers.
ANALYTICAL ENGINE(1833)
In 1833, Babbage came out with a new idea of Analytical engine, the first programmable machine. Which was
intended to be completely automatic machine having punched card input,storage unit, arithmetitc,printing unitand
control by a sequential program. Unfortunately, Babbage could not produce a working model of this machine mainly
because the standard of engineering technology was not so high at that time. However his research laid down
principles for the development of computers and is truly considered to be the father of modern digital computer,
6. The modern ages (1944 onwards)
MARK 1
The first fully automatic calculating machine was developed by Howard G
Aiken, a mathematician at Harvard University, in collaboration with
IBM(International Business Machines) corporation and was named as Mark
1. it is also known as automatic sequence controlled calculator (ASCC). it
was basically an Electro Mechanical ( relay)device since both electrical
and mechanical components were used in its design subsequent
computers were all electronic.
The Mark 1, capable of performing both arithmetic and logical opreation
was 50 feet long, 8feet high, contained 3000 electrically actuated
switches to control its operations, used 500 miles long wires and weighed
about 5 tons.
51 feet long and weighed over 5 tons
8. • The ENIAC 1946( Electronic Numerical Integrator And Calculator)
• The first all electronic computer ENIAC ( Electronic Numerical Integrator And Calculator)was
completed in 1946 by professor J.Presper Eckert and john Mouchly at the Moore School of
Electrical Engineering at the University of Pennsylvania.
• ENIAC was a comparatively fast and huge computer which occupied 20x40 square feet
room and used 18,000 vacuum tubes that is why it is called large-scale vacuum tube
computer.
• The ENIAC had two major problems, it could store and manipulate only a very limited
amount of information and its programs were wired on boards. These limitations made it
difficult to detect errors and to change the programs.
1946
9. • THE EDVAC (1949)
• To overcome the problems faced with ENIAC, john von Neumann
developed the idea of “stored program”. The first computer designed on
the stored program conept was EDVAC (electronic Discrete Variable Automatic
Computer),introduced by john von neumann.
• UNIVAC (Universal Automatic Calculator)
forty of these computers were sold to businesses. General Electric
was the first company to acquire a UNIVAC.
• The first UNIVACs were used in the US Army, Air Force, Navy,
and Atomic Energy Commission.
10. First generation Electronic computers
(1942-1955)
Major development: vacuum tubes were introduced in place of relays, stored programs
concept.
vacuum tube computer are known as “The 1st Generation” machine. A computers
developed in the initial phase of computer development (ENIAC,EDVAC,EDSAC,UNIVAC AND
MARK-1) belong to the 1st generation of computers. These generation computer used the
electronic devices like vacuum tubes, capacitor and resistors. A vacuum tube could control
and amplify electronic signals.
Advantages
1. These computers were fastest calculating devices of their time which cloud perform
computations in milliseconds.
2. Magnetic tape, Drums and Punched Cards were Developed.
Disadvantages
1. Their memory size was very limited.
2. Unreliable
3. They were too bulky in size and non –portable
4. Very expensive
5. Air conditioning requried
6. No operating system was available.
7. Slow operating speed
11. Second Generation (1955-1964)
Major Development: Transistors were used in place of vacuum tubes.
Efforts were made of reduce the size and cost of computers and also to
increase the speed and reliabilitof computers. Hence and electronic device
called transistor was invented. Transistors replaced vacuum tubes and gave
birth to 2nd generations computers.
2nd Generation computers are:
UNIACIII, IBM-1401, CDC 1604 AND IBM 7070:1400 Series;1600 series etc..
Advantages:
1. Smaller in size
2. More reliable
3. Bette portability
4. Less heat generated
5. Magnetic core used as primary memory (IBM 1401)
Disadvantages:
1. Commercial production was difficult and costly.
2. Air Conditioning required
12. Third Generation (1964-1975)
Major developments: integrated solid state circuitry, improved secondary storage devices,
new input/output devices. This generation computers also contained secondary storage
devices for large data storage. Some third generation computers are:
IBM system/360series, PDP-8Series, PDP-11Series, NCR century series etc.
Advantages :
1. Smaller in sixe than the previous generations computers.
2. Evan more reliable
3. Best portability
4. Lesser heat generated than the second generations computers
5. Less electrical consumption
Disadvantages :
1. Highly sophisticated technology required for the manufacture of IC chips
2. Air conditioning required
13. Fourth generation (1975-0NWARDS)
Major Development : Microprocessor, fourth improvement in input. Output devices.
Microprocessors were introduced as CPU
Improvements to IC technology made it possible to integrate more and more transistors in a single chip
SSI, MSI, LSI and VLSI circuits were used at the place of IC’s. They are also a single silicon chips.
SSI (Small Scale Integration): 10-100
MSI (Medium Scale Integration): 100-1,000
LSI (Large Scale Integration): 1,000-10,000
VLSI (Very Large Scale Integration): >10,000
CRT screen, laser & ink jet printers, scanners etc were developed.
Secondary memory was composed of hard disks – Floppy disks & magnetic tapes were used for backup memory.
Advantages :
1. Small in size because of high component density.
2. Very much reliable
3. Disks were used as secondary storage devices
4. Greate versatility in software
5. Introduction of micro and super computer
Disadvantages :
1. Highly sophisticated technology required for the manufacture of chips
14. Forth generation (1972-1984)
Parallelism, cache memory and virtual memory were applied
in a better way
LAN and WANS were developed (where desktop computers
were interconnected)
Introduced C language and Unix OS
Introduced Graphical User Interface
Less power consumption
High performance, lower cost and very compact
Much increase in the speed of operation
Examples are Apple Macintosh and IBM PC
15. Fifth Generation
Scientists are now working on the fifth generations computers. A promise, but
not yet a reality. They aim to bring us machines with genuine I.Q. thus, unlike
the last generations which naturally followed its growth. The fifth generation
will be totally new and totally novel. These computers will have the following
capabilities:
1. These computer will be equipped with, thinking power capabilities of
reasoning, learning, drawing inferences and making decisions like human
beings.
2. These machines will be equipped with VLSI(very large scale integration
techniques.
3. This generations of computers will depend on major advance in artificial
intelligence.
4. Highly sophisticated operating systems.
5. Introduction of parallel processing
6. Robotics
7. Super speed
16. Fifth Generation (1983-1990)
Portable note book computers introduced
Storage technology advanced – large main memory and
disk storage available
Introduced World Wide Web. (and other existing
applications like e-mail, e Commerce, Virtual
libraries/Classrooms, multimedia applications etc.)
New operating systems developed – Windows 95/98/XP/…,
LINUX, etc.
Got hot pluggable features – which enable a failed
component to be replaced with a new one without the
need to shutdown the system, allowing the uptime of the
system to be very high.
18. Analog Computers
Analog computers are used to process analog data . Analog data is one
which is of continuous nature and is not discrete or separate. Such type of
data includes temerature,pressure,speeed,weight,voltage,depth etc.
these quantities are continuous in nature. Examples of analog devices are,
watch or clock in which time is represented in a continues fashion and an
automobile speedometer etc.
Analog computers are the first computers being developed and provided
bases for development of modern digital computers.
An analog computer recognizes data as a continuous measurement of a
physical property.
It has no state
Its output is usually displayed on a meter or graphs.
Examples are Analog clock, speedo-meter of a car, thermo-meter etc
19. Digital Computers
It works with numbers
They breaks all types of information into tiny units and use
numbers to represent those pieces of information.
Everything is described in two states i.e. either ON (1) or OFF (0).
They are very fast and have big memory
