evolution of computer

ASSIGNMENT 2

EVOLUTION OF COMPUTER

1.0 1st Generation Of Computer

1.1 History Of Computer Hardware
The history of computing hardware is the record of the constant drive to make computer hardware faster, cheaper, and store more data.
Before the development of the general-purpose computer, most calculations were done by humans. Tools to help humans calculate are generally called calculators. Calculators continue to develop, but computers add the critical element of conditional response, allowing automation of both numerical calculation and in general, automation of many symbol-manipulation tasks. Computer technology has undergone profound changes every decade since the 1940s.
Computing hardware has become a platform for uses other than computation, such as automation, communication, control, entertainment, and education. Each field in turn has imposed its own requirements on the hardware, which has evolved in response to those requirements.
Aside from written numerals, the first aids to computation were purely mechanical devices that required the operator to set up the initial values of an elementary arithmetic operation, then propel the device through manual manipulations to obtain the result. An example would be a slide rule where numbers are represented by points on a logarithmic scale and computation is performed by setting a cursor and aligning sliding scales. Numbers could be represented in a continuous "analog" form, where a length or other physical property was proportional to the number. Or, numbers could be represented in the form of digits, automatically manipulated by a mechanism. Although this approach required more complex mechanisms, it made for greater precision of results.
Both analog and digital mechanical techniques continued to be developed, producing many practical computing machines. Electrical methods rapidly improved the speed and precision of calculating machines, at first by providing motive power for mechanical calculating devices, and later directly as the medium for representation of numbers. Numbers could be represented by voltages or currents and manipulated by linear electronic amplifiers. Or, numbers could be represented as discrete binary or decimal digits, and electrically-controlled switches and combinatorial circuits could perform mathematical operations.
The invention of electronic amplifiers made calculating machines much faster than mechanical or electromechanical predecessors. Vacuum tube amplifiers gave way to discrete transistors, and then rapidly to monolithic integrated circuits. By defeating the tyranny of numbers, integrated circuits made high-speed and low-cost digital computers a widespread commodity.
This article covers major developments in the history of computing hardware, and attempts to put them in context. For a detailed timeline of events, see the computing timeline article. The history of computing article treats methods intended for pen and paper, with or without the aid of tables. Since all computers rely on digital storage, and tend to be limited by the size and speed of memory, the history of computer data storage is tied to the development of computers.

1.2 Before computer hardware
The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued to be used in that sense until the middle of the 20th century. From the end of the 19th century onwards though, the word began to take on its more familiar meaning, describing a machine that carries out computations.[1]

1.3 Punched card technology
In 1801, Joseph-Marie Jacquard developed a loom in which the pattern being woven was controlled by punched cards. The series of cards could be changed without changing the mechanical design of the loom. This was a landmark point in programmability.
In 1833, Charles Babbage moved on from developing his difference engine to developing a more complete design, the analytical engine, which would draw directly on Jacquard's punched cards for its programming.[19] In 1835, Babbage described his analytical engine. It was the plan of a general-purpose programmable computer, employing punch cards for input and a steam engine for power, using the positions of gears and shafts to represent numbers. His initial idea was to use punch-cards to control a machine that could calculate and print logarithmic tables with huge precision (a specific purpose machine). Babbage's idea soon developed into a general-purpose programmable computer, his analytical engine. While his design was sound and the plans were probably correct, or at least debuggable, the project was slowed by various problems. Babbage was a difficult man to work with and argued with anyone who didn't respect his ideas. All the parts for his machine had to be made by hand. Small errors in each item can sometimes sum up to large discrepancies in a machine with thousands of parts, which required these parts to be much better than the usual tolerances needed at the time. The project dissolved in disputes with the artisan who built parts and was ended with the depletion of government funding. Ada Lovelace, Lord Byron's daughter, translated and added notes to the "Sketch of the Analytical Engine" by Federico Luigi, Conte Menabrea.[20]

1.4 Desktop calculators
By the 1900s, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word "computer" was a job title assigned to people who used these calculators to perform mathematical calculations. By the 1920s Lewis Fry Richardson's interest in weather prediction led him to propose human computers and numerical analysis to model the weather; to this day, the most powerful computers on Earth are needed to adequately model its weather using the Navier-Stokes equations.[27]
Companies like Friden, Marchant Calculator and Monroe made desktop mechanical calculators from the 1930s that could add, subtract, multiply and divide. During the Manhattan project, future Nobel laureate Richard Feynman was the supervisor of the roomful of human computers, many of them female mathematicians, who understood the use of differential equations which were being solved for the war effort.
In 1948, the Curta was introduced. This was a small, portable, mechanical calculator that was about the size of a pepper grinder. Over time, during the 1950s and 1960s a variety of different brands of mechanical calculators appeared on the market. The first all-electronic desktop calculator was the British ANITA Mk.VII, which used a Nixie tube display and 177 subminiature thyratron tubes. In June 1963, Friden introduced the four-function EC-130. It had an all-transistor design, 13-digit capacity on a 5-inch (130 mm) CRT, and introduced Reverse Polish notation (RPN) to the calculator market at a price of $2200. The EC-132 model added square root and reciprocal functions. In 1965, Wang Laboratories produced the LOCI-2, a 10-digit transistorized desktop calculator that used a Nixie tube display and could compute logarithms.

1.5 Advanced analog computers
Before World War II, mechanical and electrical analog computers were considered the "state of the art", and many thought they were the future of computing. Analog computers take advantage of the strong similarities between the mathematics of small-scale properties—the position and motion of wheels or the voltage and current of electronic components—and the mathematics of other physical phenomena, for example, ballistic trajectories, inertia, resonance, energy transfer, momentum, and so forth. They model physical phenomena with electrical voltages and currents[28] as the analog quantities.
Centrally, these analog systems work by creating electrical analogs of other systems, allowing users to predict behavior of the systems of interest by observing the electrical analogs.[29] The most useful of the analogies was the way the small-scale behavior could be represented with integral and differential equations, and could be thus used to solve those equations. An ingenious example of such a machine, using water as the analog quantity, was the water integrator built in 1928; an electrical example is the Mallock machine built in 1941. A planimeter is a device which does integrals, using distance as the analog quantity. Unlike modern digital computers, analog computers are not very flexible, and need to be rewired manually to switch them from working on one problem to another. Analog computers had an advantage over early digital computers in that they could be used to solve complex problems using behavioral analogues while the earliest attempts at digital computers were quite limited.
Some of the most widely deployed analog computers included devices for aiming weapons, such as the Norden bombsight[30] and the fire-control systems,[31] such as Arthur Pollen's Argo system for naval vessels. Some stayed in use for decades after WWII; the Mark I Fire Control Computer was deployed by the United States Navy on a variety of ships from destroyers to battleships. Other analog computers included the Heathkit EC-1, and the hydraulic MONIAC Computer which modeled econometric flows.[32]

1.6 Digital computation
The era of modern computing began with a flurry of development before and during World War II, as electronic circuit elements replaced mechanical equivalents, and digital calculations replaced analog calculations. Machines such as the Z3, the Atanasoff–Berry Computer, the Colossus computers, and the ENIAC were built by hand using circuits containing relays or valves (vacuum tubes), and often used punched cards or punched paper tape for input and as the main (non-volatile) storage medium. Defining a single point in the series as the "first computer" misses many subtleties (see the table "Defining characteristics of some early digital computers of the 1940s" below).
Alan Turing's 1936 paper[36] proved enormously influential in computing and computer science in two ways. Its main purpose was to prove that there were problems (namely the halting problem) that could not be solved by any sequential process. In doing so, Turing provided a definition of a universal computer which executes a program stored on tape. This construct came to be called a Turing machine.[37] Except for the limitations imposed by their finite memory stores, modern computers are said to be Turing-complete, which is to say, they have algorithm execution capability equivalent to a universal Turing machine.

1.7 ENIAC
The US-built ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general-purpose computer. It combined, for the first time, the high speed of electronics with the ability to be programmed for many complex problems. It could add or subtract 5000 times a second, a thousand times faster than any other machine. (Colossus couldn't add). It also had modules to multiply, divide, and square root. High speed memory was limited to 20 words (about 80 bytes). Built under the direction of John Mauchly and J. Presper Eckert at the University of Pennsylvania, ENIAC's development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, and contained over 18,000 valves. One of the major engineering feats was to minimize valve burnout, which was a common problem at that time. The machine was in almost constant use for the next ten years.
ENIAC was unambiguously a Turing-complete device. It could compute any problem (that would fit in memory). A "program" on the ENIAC, however, was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that evolved from it. Once a program was written, it had to be mechanically set into the machine. Six women did most of the programming of ENIAC. (Improvements completed in 1948 made it possible to execute stored programs set in function table memory, which made programming less a "one-off" effort, and more systematic).

1.8 First-generation machines
Even before the ENIAC was finished, Eckert and Mauchly recognized its limitations and started the design of a stored-program computer, EDVAC. John von Neumann was credited with a widely circulated report describing the EDVAC design in which both the programs and working data were stored in a single, unified store. This basic design, denoted the von Neumann architecture, would serve as the foundation for the worldwide development of ENIAC's successors.[51] In this generation of equipment, temporary or working storage was provided by acoustic delay lines, which used the propagation time of sound through a medium such as liquid mercury (or through a wire) to briefly store data. A series of acoustic pulses is sent along a tube; after a time, as the pulse reached the end of the tube, the circuitry detected whether the pulse represented a 1 or 0 and caused the oscillator to re-send the pulse. Others used Williams tubes, which use the ability of a small cathode-ray tube (CRT) to store and retrieve data as charged areas on the phosphor screen. By 1954, magnetic core memory[52] was rapidly displacing most other forms of temporary storage, and dominated the field through the mid-1970s.
The first universal programmable computer in the Soviet Union was created by a team of scientists under direction of Sergei Alekseyevich Lebedev from Kiev Institute of Electrotechnology, Soviet Union (now Ukraine). The computer MESM (МЭСМ, Small Electronic Calculating Machine) became operational in 1950. It had about 6,000 vacuum tubes and consumed 25 kW of power. It could perform approximately 3,000 operations per second. Another early machine was CSIRAC, an Australian design that ran its first test program in 1949. CSIRAC is the oldest computer still in existence and the first to have been used to play digital music.[55]

1.9 Commercial computers
The first commercial computer was the Ferranti Mark 1, which was delivered to the University of Manchester in February 1951. It was based on the Manchester Mark 1. The main improvements over the Manchester Mark 1 were in the size of the primary storage (using random access Williams tubes), secondary storage (using a magnetic drum), a faster multiplier, and additional instructions. The basic cycle time was 1.2 milliseconds, and a multiplication could be completed in about 2.16 milliseconds. The multiplier used almost a quarter of the machine's 4,050 vacuum tubes (valves).[56] A second machine was purchased by the University of Toronto, before the design was revised into the Mark 1 Star. At least seven of the these later machines were delivered between 1953 and 1957, one of them to Shell labs in Amsterdam.[57]
In October 1947, the directors of J. Lyons & Company, a British catering company famous for its teashops but with strong interests in new office management techniques, decided to take an active role in promoting the commercial development of computers. The LEO I computer became operational in April 1951 [58] and ran the world's first regular routine office computer job. On 17 November 1951, the J. Lyons company began weekly operation of a bakery valuations job on the LEO (Lyons Electronic Office). This was the first business application to go live on a stored program computer.[59]
In June 1951, the UNIVAC I (Universal Automatic Computer) was delivered to the U.S. Census Bureau. Remington Rand eventually sold 46 machines at more than $1 million each ($8.2 million as of 2010).[60] UNIVAC was the first "mass produced" computer. It used 5,200 vacuum tubes and consumed 125 kW of power. Its primary storage was serial-access mercury delay lines capable of storing 1,000 words of 11 decimal digits plus sign (72-bit words). A key feature of the UNIVAC system was a newly invented type of metal magnetic tape, and a high-speed tape unit, for non-volatile storage. Magnetic media are still used in many computers.[61] In 1952, IBM publicly announced the IBM 701 Electronic Data Processing Machine, the first in its successful 700/7000 series and its first IBM mainframe computer. The IBM 704, introduced in 1954, used magnetic core memory, which became the standard for large machines. The first implemented high-level general purpose programming language, Fortran, was also being developed at IBM for the 704 during 1955 and 1956 and released in early 1957. (Konrad Zuse's 1945 design of the high-level language Plankalkül was not implemented at that time.) A volunteer user group, which exists to this day, was founded in 1955 to share their software and experiences with the IBM 701.
In 1955, Maurice Wilkes invented microprogramming,[64] which allows the base instruction set to be defined or extended by built-in programs (now called firmware or microcode).[65] It was widely used in the CPUs and floating-point units of mainframe and other computers, such as the IBM 360 series.[66]

1.10 Univac history and structure
Eckert and Mauchly built the ENIAC (Electronic Numerical Integrator and Computer) at the University of Pennsylvania's Moore School of Electrical Engineering between 1943 and 1946. A 1946 patent rights dispute with the university led Eckert and Mauchly to depart the Moore School to form the Electronic Control Company, later renamed Eckert-Mauchly Computer Corporation (EMCC), based in Philadelphia, Pennsylvania. That company first built a computer called BINAC (BINary Automatic Computer) for Northrop Aviation (which was little used, or perhaps not at all). Afterwards began the development of UNIVAC. UNIVAC was first intended for the Bureau of the Census, which paid for much of the development, and then was put in production.
With the death of EMCC's chairman and chief financial backer Harry L. Straus in a plane crash on October 25, 1949, EMCC was sold to typewriter maker Remington Rand on February 15, 1950. Eckert and Mauchly now reported to Leslie Groves, the retired army general who had managed the Manhattan Project. Remington Rand had its own calculating machine lab in Norwalk, Connecticut, and later bought Engineering Research Associates (ERA) in St. Paul, Minnesota. In 1953 or 1954 Remington Rand merged their Norwalk tabulating machine division, the ERA "scientific" computer division, and the UNIVAC "business" computer division into a single division under the UNIVAC name. This severely annoyed those who had been with ERA and with the Norwalk laboratory.
The most famous UNIVAC product was the UNIVAC I mainframe computer of 1951, which became known for predicting the outcome of the U.S. presidential election the following year. This incident is particularly infamous because the computer predicted an Eisenhower landslide when traditional pollsters all called it for Adlai Stevenson. The numbers were so skewed that CBS's news boss in New York, Mickelson, decided the computer was in error and refused to allow the prediction to be read. Instead they showed some staged theatrics that suggested the computer was not responsive, and announced it was predicting 8-7 odds for an Eisenhower win (the actual prediction was 100-1). When the predictions proved true and Eisenhower won a landslide within 1% of the initial prediction, Charles Collingwood, the on-air announcer, embarrassingly announced that they had covered up the earlier prediction.[1]
In 1955 Remington Rand merged with Sperry Corporation to become Sperry Rand. The UNIVAC division of Remington Rand was renamed the Univac division of Sperry Rand. General Douglas MacArthur was chosen to head the company. In the 1960s, UNIVAC was one of the eight major American computer companies in an industry then referred to as "Snow White and the seven dwarfs"—IBM, the largest, being Snow White and the others being the dwarfs: Burroughs, NCR, CDC, GE, RCA and Honeywell. In the 1970s, after GE sold its computer business to Honeywell and RCA sold its to Univac, the analogy to the seven dwarfs of legend became less apt and the remaining small firms became known as the "BUNCH" (Burroughs, Univac, NCR, Control Data, and Honeywell).
Around 1975, to assist "corporate identity" the name was changed to Sperry Univac, along with Sperry Remington, Sperry New Holland, etc. In 1978 Sperry Rand, an old fashioned conglomerate of disharmonious divisions (computers, typewriters, office furniture, hay balers, manure spreaders, gyroscopes, avionics, radar, electric razors), decided to concentrate on its computing interests and unrelated divisions were sold. The company dropped the Rand from its title and reverted back to Sperry Corporation. In 1986, Sperry Corporation merged with Burroughs Corporation to become Unisys.
Since the 1986 marriage of Burroughs and Sperry, Unisys has metamorphosed from a computer manufacturer to a computer services and outsourcing firm, competing in the same marketplace as IBM, Electronic Data Systems (EDS), and Computer Sciences Corporation. Unisys continues to design and manufacture enterprise class computers with the ClearPath and ES7000 server lines.

2.0 2nd Generation Of Computer

2.1 Transistors
The bipolar transistor was invented in 1947. From 1955 onwards transistors replaced vacuum tubes in computer designs,[68] giving rise to the "second generation" of computers. Initially the only devices available were germanium point-contact transistors, which although less reliable than the vacuum tubes they replaced had the advantage of consuming far less power.[69] The first transistorised computer was built at the University of Manchester and was operational by 1953;[70] a second version was completed there in April 1955. The later machine used 200 transistors and 1,300 solid-state diodes and had a power consumption of 150 watts. However, it still required valves to generate the clock waveforms at 125 kHz and to read and write on the magnetic drum memory, whereas the Harwell CADET operated without any valves by using a lower clock frequency, of 58 kHz when it became operational in February 1955.[71] Problems with the reliability of early batches of point contact and alloyed junction transistors meant that the machine's mean time between failures was about 90 minutes, but this improved once the more reliable bipolar junction transistors became available.[72]
Compared to vacuum tubes, transistors have many advantages: they are smaller, and require less power than vacuum tubes, so give off less heat. Silicon junction transistors were much more reliable than vacuum tubes and had longer, indefinite, service life. Transistorized computers could contain tens of thousands of binary logic circuits in a relatively compact space. Transistors greatly reduced computers' size, initial cost, and operating cost. Typically, second-generation computers were composed of large numbers of printed circuit boards such as the IBM Standard Modular System[73] each carrying one to four logic gates or flip-flops.
A second generation computer, the IBM 1401, captured about one third of the world market. IBM installed more than one hundred thousand 1401s between 1960 and 1964.
Transistorized electronics improved not only the CPU (Central Processing Unit), but also the peripheral devices. The IBM 350 RAMAC was introduced in 1956 and was the world's first disk drive. The second generation disk data storage units were able to store tens of millions of letters and digits. Next to the fixed disk storage units, connected to the CPU via high-speed data transmission, were removable disk data storage units. A removable disk stack can be easily exchanged with another stack in a few seconds. Even if the removable disks' capacity is smaller than fixed disks,' their interchangeability guarantees a nearly unlimited quantity of data close at hand. Magnetic tape provided archival capability for this data, at a lower cost than disk.

3.0 3rd Generation Of Computer

3.1 Beyond
The explosion in the use of computers began with "third-generation" computers, making use of Jack St. Clair Kilby's[75] and Robert Noyce's[76] independent invention of the integrated circuit (or microchip), which later led to the invention of the microprocessor,[77] by Ted Hoff, Federico Faggin, and Stanley Mazor at Intel.[78] The integrated circuit in the image on the right, for example, an Intel 8742, is an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.
During the 1960s there was considerable overlap between second and third generation technologies.[79] IBM implemented its IBM Solid Logic Technology modules in hybrid circuits for the IBM System/360 in 1964. As late as 1975, Sperry Univac continued the manufacture of second-generation machines such as the UNIVAC 494. The Burroughs large systems such as the B5000 were stack machines, which allowed for simpler programming. These pushdown automatons were also implemented in minicomputers and microprocessors later, which influenced programming language design. Minicomputers served as low-cost computer centers for industry, business and universities.[80] It became possible to simulate analog circuits with the simulation program with integrated circuit emphasis, or SPICE (1971) on minicomputers, one of the programs for electronic design automation (EDA). The microprocessor led to the development of the microcomputer, small, low-cost computers that could be owned by individuals and small businesses. Microcomputers, the first of which appeared in the 1970s, became ubiquitous in the 1980s and beyond. Steve Wozniak, co-founder of Apple Computer, is sometimes erroneously credited with developing the first mass-market home computers. However, his first computer, the Apple I, came out some time after the MOS Technology KIM-1 and Altair 8800, and the first Apple computer with graphic and sound capabilities came out well after the Commodore PET. Computing has evolved with microcomputer architectures, with features added from their larger brethren, now dominant in most market segments.
Systems as complicated as computers require very high reliability. ENIAC remained on, in continuous operation from 1947 to 1955, for eight years before being shut down. Although a vacuum tube might fail, it would be replaced without bringing down the system. By the simple strategy of never shutting down ENIAC, the failures were dramatically reduced. Hot-pluggable hard disks, like the hot-pluggable vacuum tubes of yesteryear, continue the tradition of repair during continuous operation. Semiconductor memories routinely have no errors when they operate, although operating systems like Unix have employed memory tests on start-up to detect failing hardware. Today, the requirement of reliable performance is made even more stringent when server farms are the delivery platform.[81] Google has managed this by using fault-tolerant software to recover from hardware failures, and is even working on the concept of replacing entire server farms on-the-fly, during a service event.[82]
In the twenty-first century, multi-core CPUs became commercially available.[83] Content-addressable memory (CAM)[84] has become inexpensive enough to be used in networking, although no computer system has yet implemented hardware CAMs for use in programming languages. Currently, CAMs (or associative arrays) in software are programming-language-specific. Semiconductor memory cell arrays are very regular structures, and manufacturers prove their processes on them; this allows price reductions on memory products. When the CMOS field effect transistor-based logic gates supplanted bipolar transistors, computer power consumption could decrease dramatically (A CMOS field-effect transistor only draws significant current during the 'transition' between logic states, unlike the substantially higher (and continuous) bias current draw of a BJT). This has allowed computing to become a commodity which is now ubiquitous, embedded in many forms, from greeting cards and telephones to satellites. Computing hardware and its software have even become a metaphor for the operation of the universe.[85] Although DNA-based computing and quantum qubit computing are years or decades in the future, the infrastructure is being laid today, for example, with DNA origami on photolithography.[86]
An indication of the rapidity of development of this field can be inferred by the history of the seminal article.[87] By the time that anyone had time to write anything down, it was obsolete. After 1945, others read John von Neumann's First Draft of a Report on the EDVAC, and immediately started implementing their own systems. To this day, the pace of development has continued, worldwide.[88][89]

4.0 4th Generation Of Computer

4.1 Steve Jobs
Steven Paul "Steve" Jobs (born February 24, 1955) is an American businessman, and the co-founder and chief executive officer of Apple Inc. Jobs previously served as CEO of Pixar Animation Studios and is now a member of the Walt Disney Company's Board of Directors.
In the late 1970s, Jobs, with Apple co-founder Steve Wozniak, Mike Markkula[11] and others, designed, developed, and marketed some of the first commercially successful lines of personal computers, the Apple II series and later, the Macintosh. In the early 1980s, Jobs was among the first to see the commercial potential of the mouse-driven graphical user interface.[12][13] After losing a power struggle with the board of directors in 1985[14][15], Jobs resigned from Apple and founded NeXT, a computer platform development company specializing in the higher education and business markets. NeXT's subsequent 1997 buyout by Apple Computer Inc. brought Jobs back to the company he co-founded, and he has served as its CEO since then.
In 1986, he acquired the computer graphics division of Lucasfilm Ltd which was spun off as Pixar Animation Studios.[16] He remained CEO and majority shareholder until its acquisition by the Walt Disney Company in 2006.[2] Jobs is currently a member of Walt Disney Company's Board of Directors.[17][18]
Jobs' history in business has contributed much to the symbolic image of the idiosyncratic, individualistic Silicon Valley entrepreneur, emphasizing the importance of design and understanding the crucial role aesthetics play in public appeal. His work driving forward the development of products that are both functional and elegant has earned him a devoted following.[19]
In mid-January 2009, Jobs took a five-month leave of absence from Apple to undergo a liver transplant.[20]

4.2 Beginnings of Apple Computer
In 1976, Steve Jobs, Stephen Wozniak, Ronald Wayne[37] , and later with funding from then a semi-retired Intel product-marketing manager and engineer A.C. "Mike" Markkula Jr.[11], founded Apple. Prior to co-founding Apple, Wozniak was an electronics hacker. Jobs and Wozniak had been friends for several years, having met in 1971, when their mutual friend, Bill Fernandez, introduced 21-year-old Wozniak to 16-year-old Jobs. Steve Jobs managed to interest Wozniak in assembling a computer and selling it. As Apple continued to expand, the company began looking for an experienced executive to help manage its expansion. In 1983, Steve Jobs lured John Sculley away from Pepsi-Cola to serve as Apple's CEO, asking, "Do you want to spend the rest of your life selling sugared water to children, or do you want a chance to change the world?"[38][39] The following year, Apple set out to do just that, starting with a Super Bowl television commercial titled, "1984." At Apple's annual shareholders meeting on January 24, 1984, an emotional Jobs introduced the Macintosh to a wildly enthusiastic audience; Andy Hertzfeld described the scene as "pandemonium."[40] The Macintosh became the first commercially successful small computer with a graphical user interface. The development of the Mac was started by Jef Raskin, and eventually taken over by Jobs.
While Jobs was a persuasive and charismatic director for Apple, some of his employees from that time had described him as an erratic and temperamental manager. An industry-wide sales slump towards the end of 1984 caused a deterioration in Jobs's working relationship with Sculley, and at the end of May 1985 – following an internal power struggle and an announcement of significant layoffs – Sculley relieved Jobs of his duties as head of the Macintosh division.[41]

5.0 5th Generation Of Computer

5.1 Integrated circuit
Microchips (EPROM memory) with a transparent window, showing the integrated circuit inside. Note the fine silver-colored wires that connect the integrated circuit to the pins of the package. The window allows the memory contents of the chip to be erased, by exposure to strong ultraviolet light in an eraser device.
In electronics, an integrated circuit (also known as IC, microcircuit, microchip, silicon chip, or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface of a thin substrate of semiconductor material. Integrated circuits are used in almost all electronic equipment in use today and have revolutionized the world of electronics.
A hybrid integrated circuit is a miniaturized electronic circuit constructed of individual semiconductor devices, as well as passive components, bonded to a substrate or circuit board.

5.1.1 Introduction
Integrated circuits were made possible by experimental discoveries which showed that semiconductor devices could perform the functions of vacuum tubes, and by mid-20th-century technology advancements in semiconductor device fabrication. The integration of large numbers of tiny transistors into a small chip was an enormous improvement over the manual assembly of circuits using electronic components. The integrated circuit's mass production capability, reliability, and building-block approach to circuit design ensured the rapid adoption of standardized ICs in place of designs using discrete transistors.
There are two main advantages of ICs over discrete circuits: cost and performance. Cost is low because the chips, with all their components, are printed as a unit by photolithography and not constructed one transistor at a time. Furthermore, much less material is used to construct a circuit as a packaged IC die than as a discrete circuit. Performance is high since the components switch quickly and consume little power (compared to their discrete counterparts) because the components are small and close together. As of 2006, chip areas range from a few square millimeters to around 350 mm2, with up to 1 million transistors per mm2.

5.2 Mainframe
Mainframe may refer to one of the following:
• Mainframe computer, large data processing systems
• Mainframe Entertainment, a Canadian computer animation and design company.
• Mainframe is the city that the CGI cartoon ReBoot takes place in.
• Mainframe (band), a 1980s Electropop band
• Mainframe is the name of two fictional characters from Marvel Comics
o Mainframe (comics) appears in the series A-Next
o Mainframe appears in the Guardians of the Galaxy series
• Mainframe (Transformers) is an Autobot character in the Transformers series.
• A character in the G.I. Joe universe.
• A character from the game Gunman Chronicles.