Classification of Computers

Classification of Computers

There are 4 categories of computers-1. Super Computer2. Mainframe3. Mini Computer4. Micro Computer

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.

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.

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

Classification of Computers

…Mainframe

Separate processes (program) for •Task management •Program management •Job management •Serialisation •Catalogs •Inter address space •Communication

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.

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.

Classification of Computers

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.

Classification of Computers

…Mini Computer

• Lesser storage capacity. • Used for R&D Organisations and

Universities.• Range is from $18,000 to $50,000.

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.

Classification of Computers

…Micro Computer

• Support multitasking.

Types of Microcomputers are –

a)Desktop – small enough to fit on a desk but are too big to carry around.

b)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.

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.

Classification of Computers

Generations of Computers

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.

– Used machine language to perform operations.

UNIVAC & ENIAC

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

core storage instead of magnetic drum.

IBM-140, HONEY-WELL

…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

3rd Generation of Computers1964-1971: 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

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.

…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.

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.

…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.

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?