The first all Electronic Computer
The first all electronic computer was the ENIAC (Electronic Numerical Intregrator and computen). ENIAC was a general purpose digital computer built in 1946 by J. Presper Eckert and John Mauchly. The ENIAC contained over 18,000 vacuum tubes (used instead of the mechanical switches of the Mark I) and was 1000 times faster than the Mark I. In twenty seconds, ENIAC could do a math problem that would have taken 40 hours for one person to finish. The ENIAC was built the time of World War II had as its first job to calculate the feasibility of a design for the hydrogen bomb. The ENIAC was 100 feet long and 10 feet tall.
More Modern Computers
A more modern type computer began with John Von Neumann’s development of software written in binary code. It was Von Neumann who began the practice of storing data and instructions in binary code and initiated the use of memory to store data, as well as programs. A computer called the EDVAC (electronic Discrete Variable Computer) was built using binary code in 1950. Before the EDVAC, computers like the ENIAC could do only one task then they had to be rewired to perform a different task or program. The EDVAC’s concept of storing different programs on punched cards instead of rewiring computers led to the computers that we know today.
While the modem computer is far better and faster than the EDVAC of its time, computers of today would not have been possible with the knowledge and work of many great inventors and pioneers.
COMPUTER GENERATIONS
A generation refers to the state of improvement in the development of a product.
This term is also used in the different advancements of computer technology. With each new generation, the circuitry has gotten smaller and more advanced than the previous generation before it. As a result of the miniaturization, speed power and memory of computers has proportionally increased. New discoveries are constantly being developed that affect the way we live, work and play.
The first generation: 1946 – 1958 (the Vacuum Tube Years)
The first generation computer was huge, slow, expensive, and often undependable. In 1946 two Americans, Presper Eckert, and John Mauchly built the ENIAC electronic computer which used vacuum tubes instead of the mechanical switches of the Mark I. The ENIAC used thousands of vacuum tubes, which took up a lot of space and gave off great deal of heat just like light bulbs do. The ENIAC led to other vacuum tube type computers like the EDVAC (electronic Discrete Variable Automatic Computer) and the UNIVACI (Universal Automatic Computer)The vacuum tube was an extremely important step in the advancement of computers. Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs. It’s purpose was to act like an amplifier and a switch. Without any moving parts vacuum tubes could take very weak signals and make the signal stronger (amplify it). Vacuum tubes could also stop and start the flow of electricity instantly (switch). These two properties made the ENIAC computer possible.The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners. However even with these huge coolers, vacuum tubes still overheated regularly. It was time for something new.
The Second Generation: 1959 – 1964 (The Era of the Transistor)
The transistor computer did not last as long as the vacuum tube computer lasted, but it was no less important in the advancement of computer technology. In 1947 three scientists, John Bardeen, William Shockley and Walter Brattain working at AT & T’s Bell Labs invested what would replace the vacuum tube in that it can used to relay and switch electronic signals.
There were obvious differences between the transistor and the vacuum tube. The transistor was faster, more reliable, smaller, and much cheaper to build than a vacuum tube. One transistor replaced the equivalent of 40 vacuum tubes. These transistors were made of solid material, some of which is silicon, an abundant element (second only to oxygen) found in beach sand and glass. Therefore they were very cheap to produce.
Transistors were found to conduct electricity faster and better than vacuum tubes.
They were also much smaller and give off virtually no heat compared to vacuum tubes. Their use marked a new beginning for the computer. Without this invention, space travel in the 1960’s would not have been possible. However, a new invention would even futher advance our ability to use computers.
The third Generation: 1964 – 1970 (Intergrated Circuits – Maniaturizing the Computer)
Transistors were a tremendous breakthrough in advancing the computer. However no one could predict that thousands even now millions of transistors (circuits) could be compacted in such a small space.the intergrated circuit, or as it is sometimes referred to as semiconductor chip, packs a huge number of transistors onto a single wafer of silicon. Robert Noyce of Fairchild Corporation and Jack Kilby of Texas Instruments independently discovered the amazing attributes of integrated circuits. Placing such large number of transistors on a single chip vastly increased the power of a single computer and lowered its cost considerably.
Since the invention of intergrated circuits, the number of transistor that can be placed on a single chip has doubled every two years, shrinking both the size and cost of computers even further enhancing its power. Most electronic devices of bakelite of Fiberglass that have electrical connections etched onto them – – sometimes called a mother board.These third generation computers could carry out instructions in billionths of a second. The size of these machines dropped to the size of small file cabinets.yet, the single biggest advancement in the computer era was yet to be discovered.
The Fourth Generation: 1971 – Today (The Microprocessor)
This Generation can be characterized by both the jump to monolithic integrated circuits (millions of transistors put onto one intergrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer). By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers. Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers.However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor. Ted Hoff, employed by Intel (Robert Noyce’s new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer. The microprocessor was made to be used in calculators, not computers. It led, however, to the invention of personal computers, or microcomputers.It wasn’t until the 1970’s that people began buying computer for personal use. One of the earliest personal computers was the Altair 8800 computer kit. In 1975 you could purchase this kit and put it together to make your own personal computer.
SUMMARY OF THE COMPUTER GENERATION
1st GENERATION
The first computer used vacuum tubes for circuity and magnetic drums for memory and was often enormous taking up the entire room and relied on machine language to perform operation.
Eg:
1) UNIVAC (Universal Automatic Computer ) first commercial computer
2) ENIAC( Electronic Automatic Computer)
3) EDVAC (Electronic Discrete Variable Automatic Computer
- It uses vacuum tubes
- Used magnetic drums for memory
- Were very large taking up entire room (big and dummy)
- Computer relied on machine language to perform operation
- Were very expensive to operate
- Input was based on punished card
- Output was displayed on printouts
- Large AC needed
- High electricity consumption.
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2nd GENERATION
- Transistors replaced vacuum tubes
- Computer size reduced due to use of transistors
- Computer were relative cheaper compared to that of first generation
- Core memory was developed
- Magnetic tapes and disk were used
- First operating system was developed
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3rd GENERATION:
- Integrated circuit replaced transistors
- Capacity of computer increased
- Size of computer continued to be small
- Power consumption was low
- SSI and MSI technology was used
- High level language was used
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4th GENERATION (1971 – Present: Micro Processor)
- Development of micro processor
- Development of the internet
- Development of GUI’S
- LSI and VLSI Technology used
- RAID technology of data storage
- Computer started in the use of data commission
- Used in virtual reality a multimedia stimulator
- Different types of memories with very high accessing speed of storage capacity
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5th GENERATIONS (Present to beyond – artificial intelligence)
Fifth generation computing device based on artificial intelligence are still in development, through there are some application such as voice recognition, that are being used today.
- Used in parallel processing
- Used super conductors
- Used in speech recognition
- Used in intelligent robot
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TYPES OF COMPUTERS
Depending on the processing and size of computer, they have been classified under various types.
TYPES OF COMPUTER BASED ON THE OPERATIONAL PRINCIPLE OF COMPUTER
- Analogue computer
- Digital computer
- Hybrid computer
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ANALOG COMPUTER
These are computers that use analogy signals only. These are different from a digital computer because an analog computer can perform several mathematical operations simultaneously.
Arithmetic and logical operations are done by measuring physical changes i.e. Temperatures or pressure