Generations of Computer

Generations of Computer-Computer Generations Classified into Five Types. Each one of the five generations of computer is characterized by a major technological development that fundamentally changed the way computers operate

First Generation Computer (1949-55)

The first generation of computers used vacuum tubes for processing and machine language for giving instructions. These are extremely large in size, costly and require continuous maintenance.

Features of First Generation Computers

Used Vacuum Tubes
Big and Clumsy Computers
Electricity Consumption high
Electric Failure occurred regularly that means computers were not reliable
Large air conditioners were necessary
Programming in machine language

Some examples of First Generation computers are

ENIAC (Electronic Numerical Integrator and Calculator)
EDVAC(Electronic Discrete Variable Automatic Computer)
EDSAC(Electronic Delay Storage Automatic Computer
UNIVAC(Universal Automatic Computer)

Second Generation Computer (1956-65)

The second generation of computers used transistors in place of vacuum tubes for processing and assembly language for giving instructions. These are smaller than 1st Generation computers in size, low cost than 1st Generation computers, and require less maintenance than 1st Generation computers.

Features of Second Generation Computers

Transistor replaced Vacuum Tubes
Computer became smaller
Electricity Consumption lower
More reliable
Faster
Core memory developed
Magnetic tapes and disks used
First Operating System Developed
Programming in machine language as well as assembly language

Some examples of Second Generation computers are

LEO, ATLAS
PDP1, PDP3, PDP5, PDP8
IBM 1620, IBM 7090, IBM 7094

Third Generation Computer (1966-75)

The third generation of computers used IC(Integrated Circuits) or Chips such as SSI(Small Scale Integrated) circuits which had about 10 transistors per chip and MSI (Medium Scale Integrated) circuit which had about 100 transistors per chip in place of transistors for processing and HLL(High-Level Language) for giving instructions. These are smaller than 2nd Generation computers in size, low cost than 2nd Generation computers, and require less maintenance than 2nd Generation computers.

Features of Third Generation Computers

IC replaced Transistor
Computer became smaller, faster and more reliable
Electricity Consumption lower
High-Level language appeared

Some examples of Third Generation computers are

IBM-307, IBM-360
HONEYWELL-6000
CDC 7600
PDP II
CYBER-175

Fourth Generation Computer (1976-90)

The Fourth generation computers used VLSI(Very Large Scale Integrated) circuits which had about 50000 transistors per chip for processing and Improved HLL(High-Level Language) for giving instructions. These are smaller than 3rd Generation computers in size, low cost than 3rd Generation computers, and require less maintenance than 3rd Generation computers.

Features of Fourth Generation Computers

VLSI used
Microcomputer series such as IBM and APPLE developed
Portable computer developed
Great development in data communication
Different types of secondary memory with high storage capacity and fast access developed
Improved High-Level language appeared like C++, SQL

Some examples of Fourth Generation computers are

CRAY2, CRAY MP
IBM 3090, IBM 9000
WIPRO

Fifth Generation Computer (1990 to present)

The Fifth generation computers using ULSI (Ultra Large Scale Integrated) circuits, parallel processing, superconductors and these are helping to make artificial intelligence (AI) in reality.

Features of Fifth Generation Computers