Introduction to Computing Lecture 01 history of computers

Editor's Notes

• #2: You cannot have a positive life with a negative mind.
• #7: The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower). The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The abacus is still in use today, principally in the far east. A modern abacus consists of rings that slide over rods, but the older one pictured below dates from the time when pebbles were used for counting (the word "calculus" comes from the Latin word for pebble).
• #18: In 1642 Blaise Pascal, at age 19, invented the Pascaline as an aid for his father who was a tax collector. Pascal built 50 of this gear-driven one-function calculator (it could only add) but couldn't sell many because of their exorbitant cost and because they really weren't that accurate (at that time it was not possible to fabricate gears with the required precision). Pascal was a French mathematician and philosopher. Pascal did considerable research with regard to the pressure of liquids. He explained principle that described how a liquid in a vessel carried pressure equally in all directions. This came to be known as Pascal's Law, and had importance in the field of hydraulics. Pascal's interest in calculating may have come from a desire to assist his father with the numerous calculations required in his job as Superintendent of Taxes. In about 1642, Pascal developed a calculator called the "Arithmatique" or "Pascaline." Pascal's device used a series of toothed wheels, which were turned by hand and which could handle numbers up to 999,999.999. Pascal's device was also called the "numerical wheel calculator" and was one of the world's first mechanical adding machines.
• #23: The Step Reckoner (or Stepped Reckoner) was a digital mechanical calculator invented by German mathematician Gottfried Wilhelm Leibniz around 1672 and completed in 1694.
• #24: Just a few years after Pascal, the German Gottfried Wilhelm Leibniz (co-inventor with Newton of calculus) managed to build a four-function (addition, subtraction, multiplication, and division) calculator that he called the stepped reckoner because, instead of gears, it employed fluted drums having ten flutes arranged around their circumference in a stair-step fashion. Although the stepped reckoner employed the decimal number system (each drum had 10 flutes), Leibniz was the first to advocate use of the binary number system which is fundamental to the operation of modern computers. Leibniz is considered one of the greatest of the philosophers but he died poor and alone
• #26: Joseph Marie Jacquard
• #31: By 1822 the English mathematician Charles Babbage was proposing a steam driven calculating machine the size of a room, which he called the Difference Engine. This machine would be able to compute tables of numbers, such as logarithm tables. He obtained government funding for this project due to the importance of numeric tables in ocean navigation. By promoting their commercial and military navies, the British government had managed to become the earth's greatest empire. But in that time frame the British government was publishing a seven volume set of navigation tables which came with a companion volume of corrections which showed that the set had over 1000 numerical errors. It was hoped that Babbage's machine could eliminate errors in these types of tables. But construction of Babbage's Difference Engine proved exceedingly difficult and the project soon became the most expensive government funded project up to that point in English history. Ten years later the device was still nowhere near complete, acrimony abounded between all involved, and funding dried up. The device was never finished.
• #45: Howard Aiken began work on the Mark I at Harvard University  Mark I digital computer was completed in 1944  Mark I official name was Automatic Sequence Controlled Calculator.  Mark I functions:  Could perform arithmetic operations  Could locate information stored in tabular form. Processed numbers up to 23 digits longs and could multiply three eight‐digit numbers in 1 second.  It was not an electronic computer but as rather an electromechanical one
• #47: ENIAC – Electronic Numerical Integrator and Calculator  ENIAC was developed by Presper Eckert Jr. aand John Mauchly from 1943 to 1946.  It has 18,000 vacuum tubes and required the manual setting of switches.  It could perform 300 multiplications per Second
• #48: EDVAC is the modified version of ENIAC  EDVAC – Electronic Discrete variable automatic Computer  EDVAC employs binary arithmetic  John von Neumann invented the EDVAC
• #54: FEATURES OF FIRST GENERATION 1. Use of vacuum tubes 2. Big & Clumsy 3. High Electricity Consumption 4. Programming in Mechanical Language 5. Larger AC were needed 6. Lot of electricity failure occured   FEATURES OF SECOND GENERATION 1. Transistors were used 2. Core Memory was developed 3. Faster than First Generation computers 4. First Operating System was developed 5. Programming was in Machine Language & Aseembly Language 6. Magnetic tapes & discs were used 7. Computers became smaller in size than the First Generation computers 8. Computers consumed less heat & consumed less electricity   THIRD GENERATION FEATURES 1. Integrated circuits developed 2. Power consumption was low 3. SSI & MSI Technology was used 4. High level languages were used   FOURTH GENERATION COMPUTERS 1. LSI & VLSI Technology used 2. Development of Portable Computers 3. RAID Technology of data storage 4. Used in virtual reality, multimedia, simulation 5. Computers started in use for Data Communication 6. Different types of memories with very high accessing speed & storage capacity   FIFTH GENERATION COMPUTERS 1. Used in parallel processing 2. Used superconductors 3. Used in speech recognition 4. Used in intelligent robots 5. Used in artificial intelligence
• #57: Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. But nowadays, generation includes both hardware and software, which together make up an entire computer system. There are totally five computer generations known till date. Each generation has been discussed in detail along with their time period, characteristics. We've used approximate dates against each generations which are normally accepted. Following are the main five generations of computers: S.N.Generation & Description1First GenerationThe period of first generation: 1946-1959. Vacuum tube based.2Second GenerationThe period of second generation: 1959-1965. Transistor based.3Third GenerationThe period of third generation: 1965-1971. Integrated Circuit based.4Fourth GenerationThe period of fourth generation: 1971-1980. VLSI microprocessor based.5Fifth GenerationThe period of fifth generation: 1980-onwards. ULSI microprocessor basedFirst Generation The period of first generation was 1946-1959. First generation of computers started with using vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes like electric bulbs produced a lot of heat and were prone to frequent fusing of the installations, therefore, were very expensive and could be afforded only by very large organisations. In this generation, mainly batch processing operating systems were used. In this generation, Punched cards, Paper tape, Magnetic tape Input & Output device were used. There were machine codes and electric wired board languages used. The main features of First Generation are: Vacuum tube technology Unreliable Supported Machine language only Very costly Generate lot of heat Slow Input/Output device Huge size Need of A.C. Non-portable Consumed lot of electricity Some computers of this generation were: ENIAC EDVAC UNIVAC IBM-701 The use vacuum tubes in place of relays as a means of storing data in memory and the use of stored‐program concept.  It requires 3.5 KW of electricity per day to keep the vacuum tubes running First Generation - 1940-1956: Vacuum Tubes The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. A magnetic drum,also referred to as drum, is a metal cylinder coated with magnetic iron-oxide material on which data and programs can be stored. Magnetic drums were once use das a primary storage device but have since been implemented as auxiliary storage devices. The tracks on a magnetic drum are assigned to channels located around the circumference of the drum, forming adjacent circular bands that wind around the drum. A single drum can have up to 200 tracks. As the drum rotates at a speed of up to 3,000 rpm, the device's read/write heads deposit magnetized spots on the drum during the write operation and sense these spots during a read operation. This action is similar to that of a magnetic tape or disk drive. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language to perform operations, and they could only solve one problem at a time. Machine languages are the only languages understood by computers. While easily understood by computers, machine languages are almost impossible for humans to use because they consist entirely of numbers. Computer Programmers, therefore, use either high level programming languages or an assembly language programming. An assembly language contains the same instructions as a machine language, but the instructions and variables have names instead of being just numbers. Programs written in  high level programming languages retranslated into assembly language or machine language by a compiler. Assembly language program retranslated into machine language by a program called an assembler (assembly language compiler). Every CPU has its own unique machine language. Programs must be rewritten or recompiled, therefore, to run on different types of computers. Input was based onpunch card and paper tapes, and output was displayed on printouts. The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951. Acronym for Electronic Numerical Integrator And Computer, the world's first operational electronic digital computer, developed by Army Ordnance to compute World War II ballistic firing tables. The ENIAC, weighing 30 tons, using 200 kilowatts of electric power and consisting of 18,000 vacuum tubes,1,500 relays, and hundreds of thousands of resistors,capacitors, and inductors, was completed in 1945. In addition to ballistics, the ENIAC's field of application included weather prediction, atomic-energy calculations, cosmic-ray studies, thermal ignition,random-number studies, wind-tunnel design, and other scientific uses. The ENIAC soon became obsolete as the need arose for faster computing speeds. In electronics, a vacuum tube, electron tube (in North America), tube, or thermionic valve or valve (in British English) is a device controlling electric current through a vacuum in a sealed container. The container is often thin transparent glass in a roughly cylindrical shape. The simplest vacuum tube, the diode, is similar to an incandescent light bulb with an added electrode inside. When the bulb's filament is heated red-hot, electrons are "boiled" off its surface and into the vacuum inside the bulb. If the electrode—called a "plate" or "anode"—is made more positive than the hot filament, a direct current flows through the vacuum to the electrode (a demonstration of the Edison effect). As the current only flows in one direction, it makes it possible to convert an alternating current applied to the filament to direct current.
• #65: Second Generation The period of second generation was 1959-1965. This generation using the transistor were cheaper, consumed less power, more compact in size, more reliable and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as primary memory and magnetic tape and magnetic disks as secondary storage devices. In this generation, assembly language and high-level programming language like FORTRAN, COBOL were used. There were Batch processing and Multiprogramming Operating system used. The main features of Second Generation are: Use of transistors Reliable as compared to First generation computers Smaller size as compared to First generation computers Generate less heat as compared to First generation computers Consumed less electricity as compared to First generation computers Faster than first generation computers Still very costly A.C. needed Support machine and assembly languages Some computers of this generation were: IBM 1620 IBM 7094 CDC 1604 CDC 3600 UNIVAC 1108 Solid‐state components ( transistors and diodes) and magnetic core storage formed the basis for the second generation of Computers A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits. Second Generation - 1956-1963: Transistors Transistors replaced vacuum tubes and ushered in the second generation computer. Transistor is a device composed of semiconductor material that amplifies a signal or opens or closes a circuit. Invented in 1947 at Bell Labs, transistors have become the key ingredient of all digital circuits, including computers. Today's latest microprocessor contains tens of millions of microscopic transistors. Prior to the invention of transistors, digital circuits were composed of vacuum tubes, which had many disadvantages. They were much larger, required more energy, dissipated more heat, and were more prone to failures. It's safe to say that without the invention of transistors, computing as we know it today would not be possible. The transistor was invented in 1947 but did not see widespread use in computers until the late 50s. The transistor was far superior to the vacuum tube,allowing computers to become smaller, faster, cheaper,more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output. Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages,which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. The first computers of this generation were developed for the atomic energy industry.
• #69:  Third Generation The period of third generation was 1965-1971. The third generation of computer is marked by the use of Integrated Circuits (IC's) in place of transistors. A single IC has many transistors, resistors and capacitors along with the associated circuitry. The IC was invented by Jack Kilby. This development made computers smaller in size, reliable and efficient. In this generation, Remote processing, Time-sharing, Real-time, Multi-programming Operating System were used. High-level language (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68, etc.) were used during this generation. The main features of Third Generation are: IC used More reliable Smaller size Generate less heat Faster Lesser maintenance Still costly A.C. needed Consumed lesser electricity Support high-level language Some computers of this generation were: IBM-360 series Honeywell-6000 series PDP(Personal Data Processor) IBM-370/168 TDC-316 Third Generation - 1964-1971: Integrated Circuits The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. A nonmetallic chemical element in the carbon family of elements. Silicon - atomic symbol "Si" - is the second most abundant element in the earth's crust, surpassed only by oxygen. Silicon does not occur uncombined in nature. Sand and almost all rocks contain silicon combined with oxygen, forming silica. When silicon combines with other elements, such as iron, aluminum or potassium, a silicate is formed. Compounds of silicon also occur in the atmosphere, natural waters,many plants and in the bodies of some animals. Silicon is the basic material used to make computer chips, transistors, silicon diodes and other electronic circuits and switching devices because its atomic structure makes the element an ideal semiconductor. Silicon is commonly doped, or mixed,with other elements, such as boron, phosphorous and arsenic, to alter its conductive properties. A chip is a small piece of semi conducting material(usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components(transistors). Computers consist of many chips placed on electronic boards called printed circuit boards. There are different types of chips. For example, CPU chips (also called microprocessors) contain an entire processing unit, whereas memory chips contain blank memory. Semiconductor is a material that is neither a good conductor of electricity (like copper) nor a good insulator (like rubber). The most common semiconductor materials are silicon and germanium. These materials are then doped to create an excess or lack of electrons. Computer chips, both for CPU and memory, are composed of semiconductor materials. Semiconductors make it possible to miniaturize electronic components, such as transistors. Not only does miniaturization mean that the components take up less space, it also means that they are faster and require less energy.
• #74: Fourth Generation The period of Fourth Generation was 1971-1980. The fourth generation of computers is marked by the use of Very Large Scale Integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements and their associated circuits on a single chip made it possible to have microcomputers of fourth generation. Fourth Generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to personal computer (PC) revolution. In this generation, Time sharing, Real time, Networks, Distributed Operating System were used. All the higher level languages like C and C++, DBASE, etc., were used in this generation. The main features of Fourth Generation are: VLSI technology used Very cheap Portable and reliable Use of PC's Very small size Pipeline processing No A.C. needed Concept of internet was introduced Great developments in the fields of networks Computers became easily available Some computers of this generation were: DEC 10 STAR 1000 PDP 11 CRAY-1 (Super Computer) CRAY-X-MP (Super Computer) Fourth Generation - 1971-Present: Microprocessors The microprocessor brought the fourth generation of computers, as thousands of integrated circuits we rebuilt onto a single silicon chip. A silicon chip that contains a CPU. In the world of personal computers,the terms microprocessor and CPU are used interchangeably. At the heart of all personal computers and most workstations sits a microprocessor. Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles. Three basic characteristics differentiate microprocessors: Instruction Set: The set of instructions that the microprocessor can execute. Bandwidth: The number of bits processed in a single instruction. Clock Speed: Given in megahertz (MHz), the clock speed determines how many instructions per second the processor can execute. In both cases, the higher the value, the more powerful the CPU. For example, a 32-bit microprocessor that runs at 50MHz is more powerful than a 16-bitmicroprocessor that runs at 25MHz. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004chip, developed in 1971, located all the components of the computer - from the central processing unit and memory to input/output controls - on a single chip. Abbreviation of central processing unit, and pronounced as separate letters. The CPU is the brains of the computer. Sometimes referred to simply as the processor or central processor, the CPU is where most calculations take place. In terms of computing power,the CPU is the most important element of a computer system. On large machines, CPUs require one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. Two typical components of a CPU are: The arithmetic logic unit (ALU), which performs arithmetic and logical operations. The control unit, which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUI's, the mouse and handheld devices
• #78: Fifth Generation - Present and Beyond: Artificial Intelligence Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. Artificial Intelligence is the branch of computer science concerned with making computers behave like humans. The term was coined in 1956 by John McCarthy at the Massachusetts Institute of Technology. Artificial intelligence includes: Games Playing: programming computers to play games such as chess and checkers Expert Systems: programming computers to make decisions in real-life situations (for example, some expert systems help doctors diagnose diseases based on symptoms) Natural Language: programming computers to understand natural human languages Neural Networks: Systems that simulate intelligence by attempting to reproduce the types of physical connections that occur in animal brains Robotics: programming computers to see and hear and react to other sensory stimuli Currently, no computers exhibit full artificial intelligence (that is, are able to simulate human behavior). The greatest advances have occurred in the field of games playing. The best computer chess programs are now capable of beating humans. In May,1997, an IBM super-computer called Deep Blue defeated world chess champion Gary Kasparov in a chess match. In the area of robotics, computers are now widely used in assembly plants, but they are capable only of very limited tasks. Robots have great difficulty identifying objects based on appearance or feel, and they still move and handle objects clumsily. Natural-language processing offers the greatest potential rewards because it would allow people to interact with computers without needing any specialized knowledge. You could simply walk up to a computer and talk to it. Unfortunately, programming computers to understand natural languages has proved to be more difficult than originally thought. Some rudimentary translation systems that translate from one human language to another are in existence, but they are not nearly as good as human translators. There are also voice recognition systems that can convert spoken sounds into written words, but they do not understand what they are writing; they simply take dictation. Even these systems are quite limited -- you must speak slowly and distinctly. In the early 1980s, expert systems were believed to represent the future of artificial intelligence and of computers in general. To date, however, they have not lived up to expectations. Many expert systems help human experts in such fields as medicine and engineering, but they are very expensive to produce and are helpful only in special situations. Today, the hottest area of artificial intelligence is neural networks, which are proving successful in an umber of disciplines such as voice recognition and natural-language processing. There are several programming languages that are known as AI languages because they are used almost exclusively for AI applications. The two most common are LISP and Prolog. What does Artificial Intelligence (AI) mean? Artificial intelligence (AI) is an area of computer science that emphasizes the creation of intelligent machines that work and react like humans. Some of the activities computers with artificial intelligence are designed for include speech recognition, learning, planning and problem solving.