Generations of computer

Generations of computer

The evolution of the modern computer can be viewed in specific generations which staring from the early forties, cover 4 generations to data and we are in the middle of the 5^th generation today. Each generation was an improvement over the formal in terms of

1. Technology è used for manufacturing the machines

2. Speed èwhich increased tremendously

3. Storage è which increased tremendously

4. Size è which reduced significantly

5. Reliability è which increased considerably

6. System cost è which decreased amount 2 ½ times.

1. 1^st generation computer (1942 to 1955)

A lot of people in the computer would today regard the “ENIAC, EDVAC an  their contemporaries as being the forerunners of all digital computer  that were produced subsequently, and hence classify them under a ‘0’ generation category. The 1^st generation category

Features:-

  1. Thermionic values and vacuum tubes are used to store the instruction.

  2. The speed was limited to the mili seconds range (10^-3 )   -1000

  

  3. The internal storage used primitive devices and had a maximum capacity of 20,000 positions

  

  4. They utilized slow input and output

  

  5. They were extremely large and occupied a large amount of space.

  6.  Need  AC to run

  7. Due to the large size and nature of equipment’s used their system cost and working cost was very high.

  

  8.  They were relatively unreliable due to frequent failure to vacuum tubes and these generated the more heat

  

   9. They were restricted to scientific and commercial applications.

ENIAC :-  Electronic numerical integrator and calculator

EDVAC :- electronic discrete variable automatic computer

EDSAC :- electronic delayed storage automatic computer

 UNVAC :- universal automatic computer. 

2^nd generation computer  1955 to 1964

Between end of 50’s and 60’s there was the development of “solid-state” technology and the invention of transistors by bell laboratories. This marked the beginning of the 2^nd generation of computer.

1. Transistor are used to store the instructions in place of vacuum tube.

2. An increase in operation speed up to the micro seconds range 10-6

 3. An increase in storage capacity accommodate as muse as 1,00,000 characters .

4. The size reduced considerably due to miniaturization  of functions

5. They were a lot more reliable and the mean time between failure [mtbf] also increased.

6. Vastly improved input/output devices such as high speed card reader line printers and magnetic real tapes unit are use.

7. There was an overall reduction in system cost

8. Assembly languages translator – programs were used the later stage of this generation introduced first (HLL) high level language “Fortran in 1957

Ibm 1400, imp – 7000,  

3^rd generation computer 1965 – 1974

The world had moved into 3^rd generation of computer development. The two outstanding characteristics in this phase were the introduction of Integrated circuit technology (ICs) and development of system for automotive processing and multiprogramming

1. The electronic circuitry was based on miniature integrated circuits on silicon chips which is smaller in size, contained the equivalent of a large number of transistor. There utilized mini processors in there internal design.

2. The operating speed improved upto nano seconds range (10-⁹)

3. Internal storage increased to a capacity that could accommodate upto one half million characters.

4. A board range of improved input/output devices were introduced like the micr (magnetic ink character reader) ocr [optical character reader }   complex graphic printers and plotters etc.

5.  The greater development of HLL high level language tools place such as cobol (common business oriented language ) basic (beginners all purpose symbolic instruction code) etc.

6. System and operating cost decreased substantially as also did the cost of storage devises and media.

e.g. ibm system /360 

4^th generation 1975 up till now

around the beginning of the last decade, a number of new computers were introduced, which were based on LSIC technology [Large scale integrated circuits] and MOS technology [ Metal Oxide Semi Conductor]

characteristics of 4^th generation computer

1. The  technology used for their circuitry was so specialized and miniaturized that hundreds of ICs could be etched on a chip the size of pinhead. the use of microprocessor came into being.

2. The operating speed improved to between the nano and pico seconds rages. 10^-12

3. The internal storage capacity increased to the range of one million positions.

4. A further refinement of input/output devices took place

5. A further reduction in size also occurred.

6. The reliability increased into hundreds of hours.

7.  a further refinement of HLL (high level languages) and the introduction of special software for managing large database occurred.

e.g. 4^th generation computer are

ibm 370 series, apple, Pentium series I,II,III,IV,v

5^th generation computer

The fifth generation computer are in the development stage. these computer will use ULSI[  . they will contain millions of components on a single chip. Japan and usa have undertaken projects to design and develop such computes.  they will use improved human – machine interface. the input and output for these machines will be in the form of  graphic images or speeches. such machine will be able to interpret natural language (NLP natural language processing)

intelligence will be AI (Artificial Intelligence) 

Acronyms	Full forms
IC	Integrated circuit
LSIC	Large scale Integrated circuit
VLSIC	Very Large scale Integrated circuit
SLSIC	Super Large scale Integrated circuit
ENIAC	Electronic Numerical Integrator and calculator
EDSAC	Electronic Delayed storage automatic computer
EDVAC	Electronic discrete variable automatic computer
Univac	Universal automatic computer