Running 2 Youtube Channel : The Masti Adda (Fun based ) : The Knowledge Adda (Knowledge based) : Subscribe for Knowledge with Fun....

History of Computers

Written by @
The computers can be classified based on the evolution of technology such as :
  • Zero Generation
  • First Generation
  • Second Generation
  • Third Generation
  • Fourth Generation
  • Fifth Generation
Zeroth Generation 
These computers evolved before 1945. These computers are made use of counter wheels with mechanical components. This can do numerical operations with slow speed. An example of this generation computers is the ABACUS. 
First Generation 
This generation are evolved between 1946 and 1956. These computers are made use of Vacuum tubes, magnetic drums and cathode ray tube for displaying information and message. They had 2KB of main memory. It can execute 1000 instruction per second, could accept machine code as software. Example of this generation computers are IBM 650,UNI-VAC, UD-VAC. 
Second Generation
 Second generation computers evolved between 1957 and 1963. These computers are made use of transistors, magnetic core and drums. They had 32 KB of main memory, could execute 20000 instruction per second. It can execute and accept various language such as BASIC,FORTRAN,COBOL. Example of this generation computers are IBM 7094,CDC 6600,Honeywell 400 and Burroughs 5000. 
Third Generation
This generation of computers evolved between 1964 and 1981. This generation of computers are made use of Integrated Circuits, semiconductors in the main memory, magnetic drums as secondary memory. They had 2MB of main memory, could execute as 5 Million instruction per second. It can execute the high level language like PASCAL,C,and Computer graphics. It can be used as time sharing system. Example of this generation computers are IBM 360,Honeywell 2000,CYBER 05 and ORAY etc. 
Fourth Generation 
Fourth generation computers are evolved between 182 and 1989. This generation of computers made use of Very large scale Integration( VLSI) ,bubble memory and distributed computing system. They have 8 MB of main memory, can execute 30 millions instruction per second. They can execute the C++ language,OOPS language, voice package and wide spread of advanced software packages. Example of this generation computers are IBM 365,CRAY-XMP etc. 
Fifth Generation 
The fifth Generation computers evolved after 1990. This generation of computers are made use of advanced packing and integration technology parallel programming architecture, optical and neutral computing and 3D designing. They have main memory of 32 MB and above, can execute 1Giga and above instruction per second, is capable of executing concurrent languages, object oriented operating system, multi threaded parallel programing models, micro kernel band operating system. Example of this generation computers are CRAY-11,C-DAC, PARAM computers. 
How does microprocessor work ?
 Assume that a program and data are stored in memory. The program include binary instruction to add given data and display the answer at Seven Segment LEDs. When the microprocessor is given a command to execute the program, it reads and execute one instruction at a time and finally sends the result to the Seven segment LED for display.
The instruction are stored sequentially in memory. The microprocessor fetches the first instruction from its memory sheet,decodes it and execute that instruction. The sequence of fetch,decode and execute is continued until the microprocessor comes across an instruction to stop. During the entire process,the microprocessor uses the system bus to fetch the binary instruction and data from the memory.It uses register from the register section to store data temporarily,and it perform the computing function in the ALU section. Finally it sends out the result in binary using the same bus lines to the seven segment LED.
Technology Improvement adapted to Computer  
Technological improvements are taking place rapidly in microprocessor, microcomputer and personal computer system. Some of these improvements are listed here:
  • Increase in data bus/address bus width:The processing capability of the microprocessor can be drastically improved by increasing data size.
  • Increase in speed with high speed processors, the user can get results quickly, even with large data volumes.
  • Reduction in size and increase in capability.
  • Development of external peripherals Faster peripherals can increase the speed of processor execution and provide a good user interface.
  • Increase in memory unit size and speed.
  • Microprocessor are largely used in hand held devices operated from a battery source.This has resulted in research on the reduction of power consumption in microprocessor chips. As power consumption is reduced, these devices work for more time once the batteries are fully charged.
Back                                                                                                                         Next

No comments:

Post a Comment