Definition: ENIAC stands for Electronic Numerical Integrator and Computer. ENIAC was introduced in the world by J. Presper Eckert and John Mauchly at the University of Pennsylvania. Earlier ENIAC was used to calculate the artillery firing tables for the Ballistic Research Laboratory of United States Army.
ENIAC was the first electronic computer which was used for general purposes like solving numerical problems.The first task done by ENIAC was performing calculations for the manufacturing of a hydrogen bomb.ENIAC can be reprogrammed for the salvation of the computer related problems.
History of ENIAC
The ENIAC, assembled in 1946, was the first operational digital computer. In 1953, the built a 100-word magnetic-core memory, which was added to the ENIAC to provide it with the memory capabilities.
For providing the memory capabilities to ENIAC, a 100-word magnetic-core memory was added to the system, which was made by the Burroughs Corporation in 1953. By 1956, ENIAC was developed. It makes use of 20KW electricity, weighed over 30 tons and cost about $487000. The space occupied by ENIAC was about 1800 square feet. ENIAC make use of vacuum tubes and performed simple addition calculations at a rate of 5,000 per second (very, very slow by today's standards) and did not use transistors as transistors were not developed at that time.
The ENIAC is now being displayed at the Smithsonian Institution in Washington, D.C. In 1996, the U.S Postal Services issued a new stamp to memorialize the 50th anniversary of ENIAC. In 2011, in the honor of the 65th anniversary of the ENIAC unveiling, the city of Philadelphia, in the USA declared Feb15 as ENIAC Day. ENIAC celebrated its 70th anniversary on feb15, 2016. ENIAC was named as an IEEE Milestone in 1987.
Facts about ENIAC
• ENIAC can perform arithmetic and transfer operations, both at the same time.
• The setup time taken by ENIAC for programming of new problems is more.
• The divider and square root unit work by repeated subtraction and addition.
• ENIAC was the paradigm from which most of the other computers are developed.
• The mechanical elements of the ENIAC, which were extraneous to the calculator, include the IBM card reader for input, a punch card for output and 1500 relays.
Units of the ENIAC
Control units: It is of two types- initiating unit and cycling unit. The job of initiating unit is to control the power of the system and to start a calculation and solving. The cycling unit provides the basic signals to other units of the system so that they can transmit numbers. The cycling unit provides the choice to the user to select between the two debugging modes: "Addition Mode" or "Pulse Mode". If the user selects the Addition Mode, then the whole machine goes through the addition cycle and if the user selects Pulse Mode, then the system produces one pulse at a time.
Accumulator: An accumulator in the ENIAC works as both an ALU and a register. The accumulator can be divided into two types- the arithmetic/storage unit and the program control unit. The arithmetic/storage unit is further made up of ten wood-like slabs.
The function of each slab is to represent a digit. The decade counter receives its input from one of the five input channels and the processed numbers are transmitted through two output channels: A (Add) and S (Subtract). The performance of the accumulator depends upon the program settings.
Master Programmer: The main job of the Master Programmer is to work as a coordinator between the operations of 20 accumulators and to simplify looping.
High-speed multiplier: As we know multiplication is the main operation, so there is a need for particular hardware that can take care of this operation.So for this high-speed multiplier is used which is used to multiply two signed ten-digit numbers.
Divider/Square-rooter: This unit controls accumulators to perform the actual operations involved. It uses four accumulators, one for the numerator, one for the denominator, one for the quotient and one for shifting. The operation involves set-up, calculation, round-off and interlock and clearing.
Programmable ROM: The function tables are similar to the programmable ROM which is used nowadays in a modern computer. Memory was very costly and there are two types of memory in ENIAC- internal and external storage. The internal memory is made up of the 10 counters in the accumulators and 3 function tables. External memory is made up of punch cards and constant transmitter.
Input/Output devices- The input/output devices of the ENIAC are the IBM card reader and the Constant Transmitter. The constant transmitter is made up of electrical and mechanical components. The IBM card reader reads the values and sends the corresponding information to the constant transmitter.
Applications of ENIAC
ENIAC’s field of application includes:
• It does weather forecasting.
• ENIAC can also perform atomic-energy calculations.
• ENIAC can do the thermal ignition.
• ENIAC is also helpful for wind-tunnel design.
• ENIAC does cosmic-ray studies.
• ENIAC can also do random-number studies.
• ENIAC is used for other scientific uses.
Advantages of ENIAC
• It is a simple computer.
• It stores information.
• Tactual sensitivity is preserved.
• For faster identification of readings, color-coding is done.
• It is easily available.
• It is the fastest machine of this time and can calculate data in milliseconds.
Disadvantages of ENIAC
• ENIAC consumes more electricity.
• Its size is very large. Thus, it was not able to carry.
• It is very costly.
• It needs cold weather. So they required being housed in large air-conditioned rooms.
• Its maintenance is difficult.
• They were not very reliable.
• They get heated very soon due to thousands of vacuum tubes.
• ENIAC is non-portable.
• ENIAC is of limited commercial use.
• ENIAC uses machine language only. So the programmer must know how to deal with the machine language.
• Costly commercial production.
• Limited programming capabilities.