The First Generation Of Computers



The first generation of computers was introduced in 1946 and lasted until 1959.
During this era, computers usually worked with batch processing operating systems, which allows an execution of programs without manual intervention. Punched cards, magnetic tape as well as paper tape Input & Output devices were utilized as well.
The Central Processing Unit, often referred to as CPU is one of the most important parts in any computer.
The computer's memory and circuitry was built by using vacuum tubes.  
During this time only large and wealthy organizations were able to work with these computers. In order to understand why this was the case, we need to take a closer look at these vacuum tubes. Since their heat production was similar to electric bulbs and installations were often fused, repairs and exchanges of parts were highly expensive and therefore frequent.
Machine codes and electric wired board languages were also used for the first generation computers.

Some computers of this generation were:
  • ENIAC
  • EDVAC
  • UNIVAC
  • IBM-701
  • IBM-650




The IBM-701 




The  EDVAC 
(Electronic discrete variable automatic computer)





The main features of this generation are:
  • Vacuum tube technology
  • Unreliable
  • Supported Machine language only
  • Costly to maintain
  • High production of heat
  • Slow Input/Output device
  • Air conditioning was needed
  • Non-portable due to size
  • High consumption of energy

The Second Generation Of Computers

 

The second generation Computer IBM 1620    


The period of the second generation of computers dates from 1959 until 1965.  
As you can see in the opening picture, this generation looks more stable, more compact and easier to operate.
Due to its usage of the transistor, the computer was now cheaper to build, less power consuming and therefore became faster and more reliable than previous models.

The primary memory for this generation was made up of a magnetic core and magnetic disks, but also used tapes as a secondary storage device.
During this time of computer innovation, multiprogramming operating systems were introduced and worked alongside the batch processing system, which already aided the first generation of computers.
The newly used languages were assembly languages and high-level programming languages like FORTRAN or COBOL.
Some computers of this generation were:
  • IBM 1620
  • IBM 7094
  • CDC 1604
  • CDC 3600
  • UNIVAC 1108



The CDC 3600

The main features of this generation are:
  • Use of transistors
  • More reliable
  • More compact
  • Less consumption of energy
  • Faster 
  • Still very costly
  • Still in need of a cooling system
  • assembly and high-level programming language

The Third Generation Of Computers

The period of third generation computers started in1965 and lasted until 1971.
The third generation of computers replaced the transistor with the integrated circuit (IC), which is a set of electronic circuits on one chip.
This replacement had a strong impact on size, reliability and efficiency due to the size and structure of the integrated circuit
A single integrated circuit consists of resistors and capacitors along with the assiciated circuitry as well as many transistors.
The languages of this generation were High-level languages such as FORTRAN-II - IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68, etc.
During this time remote processing, time-sharing, real-time and multi-programming Operating Systems were introduced.

Some computers of this generation were:
  • IBM-360 series
  • Honeywell-6000 series
  • PDP(Personal Data Processor)
  • IBM-370/168
  • TDC-316



The IBM-370/168











  • The IBM-360 series






The main features of this generation are:
  • Use of Integrated Circuit
  • More reliable
  • More compact
  • Generate less heat
  • Faster
  • Lesser maintenance
  • Still costly
  • Still in need of cooling system
  • Consumed lesser electricity
  • Support of high-level language

The Fourth Generation Of Computers

The period of the fourth generation dates from 1971 to 1980.
The fourth generation computers are characterized by a bigger amount of power, smaller size, more reliability and less expenses. 
New circuits, such as the Very Large Scale Integrated (VLSI) circuits were introduced. 
Because of these new circuits, the microcomputer was able to rise, due to their 5000+ transistors, circuit elements and their associated circuits on a single chip.
All these new inventions played a major role in the technical revolution of computers and resulted in the rise of the first PC ( personal computer).
Many higher level languages such as C and C++, DBASE, etc. were now utilized.
Time sharing, real time, networks and distributed operating systems were part of the reason for the now smoother running computers.

Some computers of this generation were: 
  • DEC 10
  • STAR 1000
  • PDP 11
  • CRAY-1 (Super Computer)
  • CRAY-X-MP (Super Computer)




The PDP 11









The super computer CRAY-X-MP




The main features of this generation are:
  • VLSI technology used
  • Affordable
  • Portable
  • Use of PC
  • Pipeline processing
  • No more air conditioning needed
  • Introduction of the internet concept
  • Great developments in the fields of networks
  • Computers became accesible to the public