basics of computers

1. Classification of Computers

2. Classification of Computers
There are 4 categories of computers-
2. Super Computer
3. Mainframe
4. Mini Computer
5. Micro Computer

3. Classification of Computers
Super Computer
• The highly sophisticated computer.
• The most powerful computer made till now.
• Used for very special, highly calculation-
intensive tasks like scientific research,
weather forecasting, quantum mechanical
physics, climate research (global warming),
molecular modeling, physical simulations
(nuclear weapons), pollution control. Major
universities, military agencies and scientific
research laboratories are heavy users.

4. Classification of Computers
…Super Computer
• Very expensive, priced from $ 2 million to $
20 million.
• Consume huge electricity, enough to lighten
about 100 houses.
• Can have hundreds of processors.
• Speed is measured in nanoseconds.

5. Classification of Computers
Mainframe
A mainframe has
•1 to 16 CPUs (modern machines more)
•Memory ranges from 128 Mb over 8 Gigabyte
on line RAM
•Its processing power ranges from 80 over 550
Mips
It has often different cabinets for
•Storage
•I/O
•RAM

6. Classification of Computers
…Mainframe
Separate processes (program) for
•Task management
•Program management
•Job management
•Serialisation
•Catalogs
•Inter address space
•Communication

7. Classification of Computers
… Mainframe
• Used by large organisations for critical
applications, where many people need frequent
access to the same information.
• large and expensive
• have the ability to run multiple operating systems
and thereby operate not as a single computer but
as a number of virtual machines. A single
mainframe can replace dozens or even hundreds of
smaller servers, reducing management and
administrative costs while providing greatly
improved reliability.

8. Classification of Computers
…Mainframe
• Front End processor handles communication to
& from all the remote terminals connected to the
computer system.
•Back End processor handles retrieval operations.
• Cost is above $35000.
•Occupy entire rooms or sometimes entire floor of
a building.
• Can support upto several hundred users
simultaneously.
• Supports multiprogramming.

9. Classification of Computers
Mini Computer
• A midsized computer. In size and power, it is
less than mainframes.
• Is a multiprocessing system capable of
supporting from 4 to 200 users
simultaneously.
• Can handle a great amount of data
• Can support a number of terminals.
• Slower than mainframes but support as many
terminals as a mainframe can.

10. Classification of Computers
…Mini Computer
• Lesser storage capacity.
• Used for R&D Organisations and Universities.
• Range is from $18,000 to $50,000.

11. Classification of Computers
Micro Computer
• Small in size.
• Single user computer.
• Much slower than the larger computers.
• Used in small businesses, homes, and school/
colleges classrooms.
• Inexpensive and easy to use.
• Also called PCs in short for Personal
computers.

12. Classification of Computers
…Micro Computer
• Support multitasking.
Types of Microcomputers are –
• Desktop – small enough to fit on a desk but
are too big to carry around.
• Laptop/Notebook – portable, light weight
computers, can be carried around. can store
the same amount of data and having a
memory of the same size as that of a
personal computer.

13. Classification of Computers
…Micro Computer
c) PDA – Personal Digital Assistant is the
smallest portable computer, not bigger than a
cheque book, also known as palmtops. These
are used for keeping record of phone
numbers, dates etc. These also come with
touch screen or electronic pen.

14. Generations of Computers

15. 1st Generation of Computers
1940-1956: Vacuum Tubes
– Technology used was vacuum
tubes
– Very large in size, taking up
entire rooms.
– Generated lot of heat
– Consumed a lot of electricity
– Low capacity internal storage
– Individual non related models
– Speed of processors was in
milliseconds
– Used magnetic drum and
delay lines for Internal storage. UNIVAC & ENIAC
– Used machine language to
perform operations.

16. 2nd Generation of Computers
1956-1963: Transistors
– Vacuum tubes were replaced
with transistors
– Smaller in size than the
previous Generation
– Generated low level of heat as
components were much
smaller
– Greater reliability
– Higher capacity internal
storage
– Individual non related models
– Faster, speed of processors
was in microseconds
– Use of high cost magnetic IBM-140, HONEY-WELL
core storage instead of
magnetic drum.

17. …2nd Generation of Computers
1956-1963: Transistors
– Used Assembly
Language to perform
operations.
– High Level Programming
Languages like early
versions of COBOL &
FORTRAN were also
being developed.
IBM-1400, HONEYWELL400

18. 3rd Generation of Computers
1964-1971: Integrated Circuits
– Transistors were replaced with
IC
– Smaller in size than the
previous generation
– Remote communication facility
– Multi programming facility
– Reduced cost of direct storage
– Higher capacity of internal
storage
– Speed of processors was in
nanoseconds
– Use of high level languages
like COBOL
– Use of wide range of optical
peripherals

19. 4th Generation of Computers
1971-Present: Microprocessor
– ICs were improvised to LSI and then VLSI
– The Microprocessor brought the fourth generation
of computers, as thousands of integrated circuits
were built onto a single silicon chip.
– Smaller in size, could now fit in the palm of the hand
– Network Communication facility enhanced
– Multi programming/ Multi processing facilities
– Reduced cost of direct access storage
– Higher capacity of internal storage
– Speed of processors in picoseconds.

20. …4th Generation of Computers
1971-Present: Microprocessor
– Use of 4th generation languages.
– Much greater data processing capacity.
– Development of GUIs, the mouse, and handheld
devices.
– Web based software development for business
and other applications.

21. 5th Generation of Computers
Present and Beyond: Artificial Intelligence
– Based on Artificial Intelligence.
– Easy to use computers with high intelligence &
natural human I/P, O/P mechanisms.
– Reliable & efficient software development by new
languages, new computer architectures & system
software which overcomes previous shortcomings.
– Improved overall functions & performance aimed at
making computers smaller, lighter, faster, of greater
capacity, more flexible & more reliable.
– Are still in development, though there are some
applications, such as voice recognition, that are being
used today.

22. …5th Generation of Computers
– The use of parallel processing and
superconductors is helping to make artificial
intelligence a reality.
– The goal of fifth-generation computing is to develop
devices that respond to natural language input and
are capable of learning and self-organisation.
– Focus on Internet and Intranets.
– Non-procedural programming environment.

23. Assignment
• What is LSI, VLSI?
• Describe First generation, second
generation, third generation computers.
• Differentiate super computer and mainframe.
• Identify characteristics of fifth generation
computers.
• What is the similarity between mainframes
and minicomputers?