The Five Generations of Computers

Introduction

The first electronic computer was designed and built at the University of Pennsylvania based on the vacuum tube technology. Vacuum tubes were used to perform logic operations and to store data. Generation of computers has been divided into five according to the technology used to facilitate the processor memory, input/output units. Listed below are the various computer generation in the year of production.

First Generation (1945 - 1956)

A UNIVAC computer at the Census Bureau

Second Generation (1956-1963) Transistors

Third Generation (1964-1971) Integrated Circuits

Fourth Generation (1971-Present) Microprocessors

Fifth Generation (Present and Beyond) Artificial Intelligence

First Generation Computers

ENIAC – Electronic Numerical Integrator and Calculator

EDSAC – Electronic Daily Storage Automatic Calculator

EDVAC – Electronic Discrete Variable Automatic Computer

UNIVAC – Universal Automatic Computer

Characteristics

Vacuum tubes were used

Very bulky

Consumed more power and limited performance

High cost

Used assembly language to prepare programs.

Mercury delay line memories and electronic memories were used

Fixed point arithmetic was used.

Second Generation Computers

Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.

Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

The first computers of this generation were developed for the atomic energy industry.

Characteristics

Transistors were used in place of vacuum tubes

Smaller in size

Lesser power consumption and better performance

Lower cost

Magnetic ferrite core memory used as main memories which is a random access non volatile memory

Magnetic tape and magnetic disc were used as secondary memories

Hardware for floating point arithmetic operations were developed

Index registers were introduced which increased flexibility of programming

Separate Input/output processes were developed that could operate parallel with CPU

Third Generation Computers

The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

Characteristics

Integrated circuits were used

Small scale integration and medium scale integration technology was implemented in CPU

Small and better performance

Comparatively lesser cost

Faster processors

In the beginning magnetic core memories were used

Operating systems software were used

Fourth Generation Computers

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. 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.

In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. 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. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

Characteristics

(Intel 8086, 80186, 80286, 80386, 80486, Motorola 68000, 68030, 68040, Apple II etc)

Microprocessors were introduced as CPUs

Tens of thousands of transistors can be placed in a single chip

CRT screens, laser and inkjet printers, scanners etc were developed

Secondary memory were composed of hard discs

Floppy disk and magnetic tapes were used for backup memories

LAN and WAN were developed where desktop workstations interconnect

Graphic user interface was introduced

Less power consumption, high performance, lower cost

Much increase in speed of operation

Introduced C Language and UNIX Operation System

Fifth Generation Computers

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.

Characteristics

(IBM notebooks, Pentium PCs: Pentium I, Pentium II, Pentium III, Pentium IV, Dual core/Quad Core, Sunwork Stations, origin 2000, PARAM 10000, IBM SP/)

Computers used extensive parallel processing, multiple pipelines, multiple processors etc.

Massive parallel machines and extensively distributed systems connected by communication network fall in this category

Introduced ultra large scale integration technology, Intel Pentium microprocessor contains 55million transistors of components on a single chip, memory chip up to 1GB, hard disc drive up to 180GB and optical disc up to 27GB were available. Object oriented language like Java Script suitable for internet programming was developed. Introduced the World Wide Web.