Fifth-Generation Computers ( 1990 and Beyond)

Scientists are now at work on the fifth-generation of computers. this is still not a reality, but recent engineering advances have made it possible for computers to be able to accept spoken words (voice recognition) and inmate human reasoning. There-fore they are thought to have Artificial Intelligence. The ability to translate a foreign language is also moderately possible with fifth-generation computers.

The term fifth generation was intended to convey the system as being a leap beyond existing machines. Computers using vacuum tubes were called the first generation; transistors and diodes, the second; integrated circuits, the third; and those using microprocessors, the fourth. Whereas previous computer generations had focused on increasing the number of logic elements in a single CPU, the fifth generation, it was widely believed at the time, would instead turn to massive numbers of CPUs for added performance. The project was to create the computer over a ten year period, after which it was considered ended and investment in a new, Sixth Generation project, began. Opinions about its outcome are divided: Either it was a failure, or it was ahead of its time.

Fourth-Generation Computers ( 1971 onwards)

Fourth-Generation computers used Very Large Scale Integration (VLSI) technology. After the induction of integrated circuits, computers could only get smaller in size, since hundreds of components could fit onto one chip. By the 1980s, the use of VLSI technology had squeezed hundreds of thousands of components onto a single chip. Ultra-large Scale Integration (ULSI) increased that number to millions. This also helped decrease the price of computers. It also increased their power, efficiency and reliability. Examples of such computers are IBM-PC, Apple Machintosh, SUN SPARCstation, etc.

The advantages of fourth-generation computers over third-generation computers are:

1. They were cheaper

2. They had a larger memory and high functional speed.

3. They consumed less power.

4. They generated a negligible amount of heat.

Third-Generation Computers (1964 - 1971)

In the third generation of computers integrated circuits (ICs) began to be used. These ICs were called chips. An IC is more compact than a transistor. A single IC has many transistors, registers and capacitors, placed on a single thin slice of silicon. So, the computer built of such components become smaller. Some of the computers developed during this period were :

IBM-360: Developed by IBM in 1964

PDP-8: Developed by DEC in 1965

PDP-11: Developed by DEC in 1970

CRAY-1: Developed by Cray Research in 1974

VAX: Developed by DEC in 1978.

High-Level languages such as BASIC (Beginners All-purpose Symbolic Instruction Code) were developed during this period.

The advantages that the third-generation computers had over the second-generation computers were:

1. They were smaller in size as compared to the second-generation computers.

2. They generated less heat.

3. They reduced computational time.

4. They involved low maintenance cost.

5. They were easily portable.

6. They required less power to keep them going.

7. They were comparatively cheaper.

Second-Generation Computers

In this generation of computers, transistors were used in place of vacuum tubes. Transistors are more compact than vacuum tubes as they are made up of semiconductors. they are also more durable than vacuum tubes. Programming languages such as COBOL and FORTRAN were developed during this period. Some of the computers of the second generation are:

IBM 1620: Its size was smaller as compared to the first-generation computers and it was used mostly for scientific purposed.

IBM 1401: It was used for business applications

CDC 3600 : It was used for scientific purposes.

The advantages that the second-generation computers had over the first-generation computers are:

1. They were smaller as compared to the first-generation computers

2. They generated less heat.

3. They took comparatively less computational time.

4. They were less prone to failure.

The disadvantages that second-generation computers had as compared to the first-generation computers are:

1. They required air conditioning

2. Frequent maintenance was required.

3. They were difficult to produce and were quite expensive.

First Generation Computers (1945 - 1956)

First-generation computers used vacuum tubes and valves as their basic electronic component. They were extremely large in size and not reliable. The language used for storing and processing data was machine language. Some of the first-generation computers are:-

ENIAC (Electronic Numerical Integrator and Calculator): It was built in 1946 at the University of Pennsylvania, (USA, by John Eckert and John Mauchly.

EDVAC (Electronic Discrete Variable Automatic Computer): It was developed in 1950

EDSAC (Electronic Delay Storage Automatic computer): It was developed by MV Wilkes at Cambridge University in 1949.

UNIVAC-1: The Universal Automatic Computer was USA's first commercially available computer system. It was delivered in 1951 by the Eckert-Mauchly Computer Corp.

Disadvantages

The shortcomings of the first-generation computers were as follows:

1. They were too bulky

2. they emitted large amounts of heat because they used lots of vacuum tubes.

3. Air conditionaing was required.

4. They were prone to frequent faliure; that's why they were unreliable.

5. They were not portable