History and Development of Computers

History and Development of Computers

Early Computing Machines:

Abacus: Evolution of computer goes to a very elementary counting device called the ABACUS, developed around 5000 years ago in china. It was the first mathematical device used to facilitate arithmetic computation and is still in use today, and may be considered the first computer. This device allows users to make computations using a system of sliding beads arranged on a rack. Early merchants used the abacus to keep trading transactions. But as the use of paper and pencil spread, particularly in Europe, the abacus lost its importance.

Pascaline (Pascal Arithmetic Machine): Pascaline was invented by Blaise Pascal in 1642 that added and subtracted, automatically carrying and borrowing digits from column to column. Pascal built 50 copies of his machine.

Leibnitz Arithmetic Machine: In 1694, a German mathematician and philosopher, Gottfried Wilhem von Leibnitz, improved the pascaline by creating a machine that could also multiply and divide. Like its predecessor, Leibnitz’s mechanical multiplier worked by a system of gears and dials.

Charles Babbage’s Analytical and Difference Engine: The real beginnings of computers started with the invention of Difference Engine in 1822 and an Analytical Engine by English Mathematics professor, Charles Babbage. The Difference Engine was a mechanical device that could count and subtract, but could run only single algorithm. The Analytical Engine on the other hand had advanced features and mainly contained four components: the store (memory), the mill (computation unit), the input section and the output section. The great advantage of the Analytical Engine was that it was general purpose. But, Charles Babbage’s Engines suffered from the problem of frequent breakdowns.

Lady Augusta Ada contributed in the refinement of this machine by inventing and using a new number system called the binary number system using only two digits ‘0’ and ‘1’ instead of using decimal digits.

Hollerith Punch Card Machine: In 1889, an American Inventer, Herman Hollerith invented a punch card machine to process census data. The data was in punch cards in coded form. He designed a wire brush with a wire for each possible location. The card was placed on a metal plate. Wires made contact with plate in the punched hole locations and generated electric pulses. This machine was very successful for tabulation work. This aided to the development of data processing machine. Hollerith brought his punch card reader into the business world, founding Tabulating Machine Company in 1896. Hollerith’s Tabulating Machine Company eventually merged with other companies in 1924 to become International Business Machine (IBM).

In the coming years, several engineers made other significant advances like: Vannevar Bush developed a calculator for solving differential equations in 1931. The machine could solve complex differential equations. The machine was cumbersome because hundreds of gears and shafts were required to represent numbers and their various relationships to each other. To eliminate this bulkiness, John V. Atanasoff, a Professor at Lowa State College and his graduate student, Clifford Berry, envisioned an all-electronic computer that applied Booloean algebra to computer circuitry. This approach was based on the mid-19^th century work of George Boole who clarified the binary system of algebra, which stated that any mathematical equations could be stated simply as either true or false. By extending this concept to electronic circuits in the form of on or off, Atanasoff and Berry had developed the first all-electronic computer by 1940. Their project, however, lost its funding and their work was overshadowed by similar developments by other scientists.

In the 1930s American mathematician Howard Aiken developed the Mark I calculating machine, which was built by IBM. This electronic calculating machine used relays and electromagnetic components to replace mechanical components. In later machines, Aiken used vacuum tubes and solid state transistors to manipulate the binary numbers. Aiken also introduced computers to universities by establishing the first computer science program at Harvard University.

At the Institute for Advanced Study in Princeton, Hungarian-American mathematician John von Neumann developed one of the first computers used to solve problems in mathematics, meteorology, economics, and hydrodynamics. Von Neumann’s 1945 Electronic Discrete Variable Computer (EDVAC) was the first electronic computer to use a program stored entirely within its memory.

John Mauchely, an Americian physicist, proposed an electronic digital computer, called the Electronic Numerical Intergrator And Computer (ENIAC), which was built at the Moore School of Engineering at the University of Pennsylvania in Philadelphia by Mauchely and J. Presper Eckert, an American Engineer. ENIAC was completed in 1945 and is regarded as the first successful, general digital computer. It weighed more than 27,000 kg and contained more than 18,000 vacuum tubes. Many of ENIAC’s first task were for military purposes, such as calculating ballistic firing tables and designing atomic weapons.

Eckert and Mauchley eventually formed their own company, which was then bought by the Rand Corporation. They produced the Universal Automatic Computer (UNIVAC), which was used for a broader variety of commercial applications. UNIVAC was the first successful commercial computer.

In 1948, at Bell Telephone Laboratories, American physicists Walter Houser Brattain, John Bardeen, and William Bradford Shockely developed the transistor, a device that can act as an electric switch. The transistor has a tremendous impact on computer design, replacing costly, energy-inefficient, and unreliable vacuum tubes.

In the late 1960s integrated circuits(IC), tiny transistors and other electrical components arranged on a single chip of silicon, replaced individual transistors in computers. ICs became miniaturized, enabling more components to be designed into a single computer circuit. In the 1970s refinements in the integrated circuit technology led to the development of the modern microprocessor, integrated circuits that contained thousands of transistors. Modern microprocessors contain as many as 10 million transistors.

Manufacturers used integrated circuit technology to build smaller and cheaper computers. The first of these so-called personal computers (PCs) was sold by Instrumentation Telemetry Systems. The Altair 8800 appeared in 1975. It used an 8-bit Intel 8080 microprocesor, had 256 bytes of RAM. Refinement in the PC continued with the inclusion of video displays, better storage devices, and CPUs with more computational abilities. Graphical user interfaces were first designed by the Xerox Corporation, then later used successfully by the Apple Computer Corporation with its Macintosh computer. Today the development of sophisticated operating systems such as Windows 95,98,XP and UNIX enables computer users to run programs and manipulate data in ways that were unimaginable 50 years ago.

Possibly the largest single calculation was accomplished by physicists at IBM in 1995 solving one million trillion mathematical problems by continuously running 448 computers for two years to demonstrate the existence of a previously hypothetical subatomic particle called a glueball. Japan, Italy, and the United States are collaborating to develop new supercomputers that will run these calculations one hundred times faster.

In 1996 IBM challenged Gary Kasparov, the world chess champion, to a chess match with a supercomputer called Deep Blue. The computer had the ability to compute more than 100 million chess positions per second. Kasparov won the match with three wins, two draws, and one loss. Deep Blue was the first computer to win a game against a world chess champion with regulation time controls. Deep Blue served as a prototype for future computers that will be required to solve complex problems.

Analog and Digital Computers

On the basis of work or operational principle, computers can be classified as analog computers, digital computers, and hybrid computers.

·   Analog Computers: Analog computers process values that have continuous range rather than digital values (two possible values). These computers work with natural phenomena and physical values like frequency, temperature, pressure, speed, earthquake, water flow, current flow etc. These computers are based on continuous changing values or voltage levels. These types of computers are generally used in scientific work and not for commercial or personal purpose. A popular analog computer used the 20^th century was slide rule. Some other examples are: thermometer, speedometer, odometer, seismograph etc. Some of its characteristics are listed below:

o   Based on continuous varying data.

o   Measures only natural or physical values.

o   Used for special purpose.

o   Generally, no storage facility is available because they work on real time basis. If provided, only little amount of storage is available in it.

o   Accuracy is very low because of noise and less filtering facility.

o   It has slow processing.

·   Digital Computers: Digital computers process digital values. Digital refers to the processes in computers that manipulate binary numbers (0s and 1s). Meaning of 0 is off and 1 is on. So, the basic principle of these computers is either present or absent of electric current. Some examples are IBM PC, Apple/Macintosh. Some major characteristics of these computers are listed below:

o   Based on discrete data which are not continuous with time.

o   Based on the principle of logic 1 and 0 or on or off.

o   Used for general purpose.

o   More reliable because off less noise and high filtering capacity.

o   It has large storage capacity because the calculations are to be stored internally for future use.

o   It is multipurpose and programmable.

o   It has faster processing.

·   Hybrid Computers: Hybrid means combination or cross-link of two or more types. So, as the name suggests, it is the combination of both analog and digital computers. It can perform the work done by analog computers as well as by digital computers. These computers are generally used in hospitals, aeroplanes etc. Some of the major characteristics of these computers are given below:

o   Combination of good qualities of analog as well as digital computer.

o   Can process both continuous and digital data.

o   It has capacity to convert one type of data into another.

o   These are special purpose machines.

o   Mostly used in hospitals and airplanes.

o   High cost.

Generation of Computer

Each generation of computer is characterized by major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful, more efficient, and reliable devices. According to this there are five generation of computers as described below:

1.      The First Generation: (1945-55) Vacuum Tubes and Plug boards

Characteristics:

o   These machines were enormous, filling up entire rooms with tens of thousands of vacuum tubes, but were much slower than even the cheapest personal computer available today.

o   First generation computer relied on machine language to perform operations, and they could only solve one problem at a time.

o   Input was punched on punched cards and paper tape, and output was displayed on printers.

o   Some examples are UNIVAC, ENIVAC etc.

Advantages:

• Vacuum tubes were the only electronic components available during those days
• Vacuum tube technology made possible the advent of electronic digital computers
• These computers were the fastest calculating device of their time. They could perform computations in milliseconds

Disadvantages:

• Too bulky in size so not portable
• Unreliable
• Thousands of vacuum tubes that were used emitted large amount of heat and burnt out frequently
• Air conditioning required
• Prone to frequent hardware failures
• Constant maintenance required
• Manual assembly of individual components into functioning unit required
• Commercial production was difficult and costly so limited to commercial use

2.      The Second Generation: (1955-65) Transistors and Batch Systems

Characteristics:

o   Transistors were used as a basic building block for second generation computers.

o   Second generation computers moved from cryptic binary machine language to symbolic, or assembly language, which allows programmers to specify instructions in words. High level languages were also being developed at this time like early version of FORTRAN and COBOL.

o   These were also the first computer that stored their instructions in their memory.

o   Second generation computer still relied on punched card for input and printer for output.

Advantage:

• Smaller in size as compared to first generation computers
• More reliable
• Less heat generated
• These computers were able to reduce computational times from milliseconds to microseconds
• Less prone to hardware failures
• Better portability
• Wider commercial use

Disadvantage:

• Air conditioning required
• Frequent maintenance required
• Manual assembly of individual components into a functional unit was required
• Commercial production was difficult and costly

Advances in electronics technology continued and the advent of “microelectronic”

Technology made it possible to integrate large number of elements into very small

(less than 5mm square) surface of silicon known as “ chips”. This new technology was called “integrated circuit” (ICs).

3.      The Third Generation: ( 1965- 1980 ) ICs and multiprogramming

Computer chips called IC (Integrated Circuits) were introduced, which was a basic building block for this generation of computer.

Concept of Multiprogramming was introduced in which when no. of jobs are to be performed, main memory is divided into several pieces with different job in each partition. While one job was waiting for input/output to computer, another job could be using the CPU. If enough job could be held in main memory at once, the CPU could be kept busy nearly 100% of the time.

Advantages:

·         Smaller in size as compared to previous generation computer.

·         Even more reliable than second generation

·         Even lower heat generated than 2^nd generation

·         These computers were able to reduce computational times from microsecond to nanoseconds.

·         Maintenance cost is low because hardware failures are rare.

·         Easily portable

·         Totally general purpose. Widely used for various commercial applications all over the world

·         Less power requirement than previous generation

·          Manual assembly of individual components into a functioning unit not required. So human labor and cost involved at assembly stage reduced drastically.

·         Commercial production was easier and cheaper

Disadvantages:

·         Air-conditioning required in many cases

·         Highly sophisticated technology required for the manufacture of IC chips.

4. Fourth Generation (1980 onwards)

Initially, the integrated circuits contained only about ten to twenty components. This technology was named small scale integration (SSI). Later, with the advancement in technology for manufacturing IC’s, it became possible to integrate up to a hundred components on a single chip. This technology came to be known as medium scale integration (MSI). Then came the era of large scale integration (LSI), when it was possible to integrate over 30,000 components onto a single chip. Then more advance technology like very large scale integration (VLSI) came. Development of GUI, mouse, and handheld devices took place in this generation.

Advantages:

·         Smallest in size because of high component density

·         Very reliable

·         Heat generated is negligible

·         No air conditioning required in most cases

·         Much faster in computation than previous generations

·         Hardware failure is negligible and hence minimal maintenance is required

·         Easily portable because of their small size

·         Totally general purpose

·         Minimal labor and cost involved at assembly stage

·         Cheapest among all generations

Disadvantages:

·         Highly sophisticated technology required for the manufacture of LSI chips.

5. Fifth Generation (Present and Beyond)

Defining the fifth generation of computers is somewhat difficult because the field is in its infancy. Using recent engineering advances, computers are able to accept spoken word instructions (voice recognition) and imitate human reasoning. The ability to translate a foreign language is also moderately possible with fifth generation computers.

Many advances in the science of computer design and technology are coming together to enable the creation of fifth-generation computers. Some of such engineering advances are parallel processing, and another is superconductor technology, which allows the flow of electricity with little or no resistance, greatly improving the speed of information flow. The concept of using bio chips in computers is also being worked out in the research labs to make the computer to have an ability to think.