Class IX_Computer fundamental- Unit 1
1.1 Introduction
to Computer
Computer is an electronic
device/ machine that takes data as a input from user, processes them and gives
output in the form of meaningful information. It accepts different forms of
input such as data, programs and user reply.
OR
Computer is a programmable
machine which has two principal characteristics;
- It responds to a specific set of instructions in a well-defined manner.
- It can execute a prerecorded list of instructions (a program).
Data is the raw details
and/or collection of facts, figure and etc about any Entity (Person, place,
thing, event etc) that need to be processed to generate useful information.
Information is the
processed form of data which gives a specific meaning.
Programs are the set of
instruction that can be executed by the computer in sequential of random manner
to perform a specific task.
Computer System Collection
of different electronic devices (such as Mouse, Keyboard, Monitor, CPU,
Speaker, Volt guard/ Spike guard etc) that works all together to perform a
specific task is known as Computer System. The main task of computer system is
to process the given input of any type in efficient manner. Therefore
computer is also known by various other names such as Data Processing Unit,
data processor and Data Processing System.
The devices that include a
computer system are;
Central Processing Unit (CPU):
CPU is considered as most significant component of the computer. It is also the
"brain" of compute. It is the processor of computer which is
responsible for controlling and executing instruction in the computer.
Monitor: It is the screen
that displays the information in visual form after receiving the video signal
from the computer. It is also known as output devices which generates the soft
copy output.
Keyboard and mouse: These
are the input devices that are used by the computer to receive the input from
the user.
Characteristics of computer
Speed (कार्य वेग): Computer is a
fast electronic device which can solve large and complex problem in a few
seconds. The speed of computer depends up on the configuration of its hardware
components. Generally the work speed of computer is measured as the following
seconds.
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S.N
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Unit
of Time
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Parts
of 1 Second
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Multiple
of 10
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1
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Millisecond
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1/1000th
Second
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10-3
Second
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2
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Micro
Second
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1/1000000th
Second
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10-6
Second
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3
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Nano
Second
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1/1000000000th
Second
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10-9
Second
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4
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Pico
Second
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1/1000000000000th
Second
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10-12
Second
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5
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Festo
Second
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1/1000000000000000th
second
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10-15
Second
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Automatic (स्वचालित): As Computer is
an electronic machine; it performs its entire task according to the instruction
set (Program). So once a task is initiated, computers can proceed on its own
till its completion. Computers can be programmed to perform a series of complex
tasks involving multiple programs.
Storage Capacity (संचय/ à¤à¤£्डारण क्षमता): A
computer can store huge amount of data in its different storage components in a
may different formats. The storage capacity of computer is measured in bytes.
The capacities are described using the unit of bytes.
One character (0,1) = 1 Bit
4 Bit = 1 Nibble
8 Bit = 1 Byte
1024 Bytes = 1 Kilo Byte
1024 Kilo Byte = 1 Mega Byte
1024 Mega Byte = 1 Giga Byte
1024 Giga Byte = 1 Tera Byte
1024 Tera Byte = 1 Peta Byte
The number of bits that a
computer can process at a time in a parallel is called its word Length. Commonly
used word lengths are 8, 16, 32, 64 bits.
Accuracy (दुरुस्तता/ शुद्धता): The
accuracy of computer is very high. The accuracy of achieved by the compute
depends up on its hardware configuration and the instructions. Errors in
hardware can occur, but error detecting and correcting techniques will prevent
false results. in most cases, the errors are due to the human factors rather
than the technological flaws.
Versatility (बहुउपयोगी/ परिवर्तनशील):
Computers are very versatile machine. They can perform activities ranging from
simple calculations to performing complex CAD modeling and simulations to
navigating missiles and satellites. They are capable of performing almost any
task and can be used for many different purposes.
Diligence (लगनशील ): computer is a
dumb machine and therefore lacks of ‘common sense”. Anything it does is the
result of human instructions. Therefore, computer can perform repetitive
calculations any number of times with the same accuracy. Computer do not
suffers from human traits, such as tiredness, fatigue, lack of concentration,
etc.
1.2 History of computers and
its generations
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1939
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Hewlett and Packard in the garage workshop courtesy HP
Archives
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Hewlett-Packard
is Founded. David Packard and Bill Hewlett found Hewlett-Packard in a Palo
Alto, California garage. Their first product was the HP 200A Audio
Oscillator, which rapidly becomes a popular piece of test equipment for
engineers. Walt Disney Pictures ordered eight of the 200B model to use as
sound effects generators for the 1940 movie “Fantasia.”
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1940
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The Complex Number Calculator (CNC)
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The
Complex Number Calculator (CNC) is completed. In 1939, Bell Telephone
Laboratories completed this calculator, designed by researcher George
Stibitz. In 1940, Stibitz demonstrated the CNC at an American
Mathematical Society conference held at Dartmouth College. Stibitz
stunned the group by performing calculations remotely on the CNC (located in
New York City) using a Teletype connected via special telephone lines. This
is considered to be the first demonstration of remote access computing.
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1941
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The Zuse Z3 Computer
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Konrad
Zuse finishes the Z3 computer. The Z3 was an early computer built by German
engineer Konrad Zuse working in complete isolation from developments
elsewhere. Using 2,300 relays, the Z3 used floating point binary arithmetic
and had a 22-bit word length. The original Z3 was destroyed in a bombing raid
of Berlin in late 1943. However, Zuse later supervised a reconstruction of
the Z3 in the 1960s which is currently on display at the Deutsches Museum in
Munich.
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Bombe replica, Bletchley Park,
U.K.
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The
first Bombe is completed. Based partly on the design of the Polish “Bomba,” a
mechanical means of decrypting Nazi military communications during WWII, the
British Bombe design was greatly influenced by the work of computer pioneer
Alan Turing and others. Many bombes were built. Together they
dramatically improved the intelligence gathering and processing capabilities
of Allied forces. [Computers]
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1942
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The Atanasoff-Berry Computer
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The
Atanasoff-Berry Computer (ABC) is completed. After successfully demonstrating
a proof-of-concept prototype in 1939, Atanasoff received funds to build the
full-scale machine. Built at Iowa State College (now University), the
ABC was designed and built by Professor John Vincent Atanasoff and graduate
student Cliff Berry between 1939 and 1942. The ABC was at the center of a
patent dispute relating to the invention of the computer, which was resolved
in 1973 when it was shown that ENIAC co-designer John Mauchly had come to
examine the ABC shortly after it became functional.
The legal result was a landmark: Atanasoff was declared the originator of several basic computer ideas, but the computer as a concept was declared un-patentable and thus was freely open to all. This result has been referred to as the "dis-invention of the computer." A full-scale reconstruction of the ABC was completed in 1997 and proved that the ABC machine functioned as Atanasoff had claimed. |
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1943
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Whirlwind installation at MIT
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Project Whirlwind begins. During World War
II, the U.S. Navy approached the Massachusetts Institute of Technology (MIT)
about building a flight simulator to train bomber crews. The team first built
a large analog computer, but found it inaccurate and inflexible. After
designers saw a demonstration of the ENIAC computer, they decided on building
a digital computer. By the time the Whirlwind was completed in 1951, the Navy
had lost interest in the project, though the U.S. Air Force would eventually
support the project which would influence the design of the SAGE program.
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George Stibitz circa 1940
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The Relay Interpolator is completed. The
U.S. Army asked Bell Labs to design a machine to assist in testing its M-9
Gun Director. Bell Labs mathematician George Stibitz recommended using a
relay-based calculator for the project. The result was the Relay
Interpolator, later called the Bell Labs Model II. The Relay Interpolator
used 440 relays and since it was programmable by paper tape, it was used for
other applications following the war.
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1944
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Harvard Mark-I in use, 1944
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Harvard
Mark-1 is completed. Conceived by Harvard professor Howard Aiken, and
designed and built by IBM, the Harvard Mark-1 was a room-sized, relay-based
calculator. The machine had a fifty-foot long camshaft that synchronized the
machine’s thousands of component parts. The Mark-1 was used to produce
mathematical tables but was soon superseded by stored program computers.
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The Colossus at Work At
Bletchley Park
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The
first Colossus is operational at Bletchley Park. Designed by British engineer
Tommy Flowers, the Colossus was designed to break the complex Lorenz ciphers
used by the Nazis during WWII. A total of ten Colossi were delivered to
Bletchley, each using 1,500 vacuum tubes and a series of pulleys transported
continuous rolls of punched paper tape containing possible solutions to a
particular code. Colossus reduced the time to break Lorenz messages from
weeks to hours. The machine’s existence was not made public until the 1970s
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1945
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John von Neumann
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John
von Neumann wrote "First Draft of a Report on the EDVAC" in which
he outlined the architecture of a stored-program computer. Electronic storage
of programming information and data eliminated the need for the more clumsy
methods of programming, such as punched paper tape — a concept that has
characterized mainstream computer development since 1945. Hungarian-born von
Neumann demonstrated prodigious expertise in hydrodynamics, ballistics,
meteorology, game theory, statistics, and the use of mechanical devices for
computation. After the war, he concentrated on the development of Princeton´s
Institute for Advanced Studies computer and its copies around the world.
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1946
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ENIAC
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In February, the public got its first glimpse of the ENIAC, a
machine built by John Mauchly and J. Presper Eckert that improved by 1,000
times on the speed of its contemporaries.
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AVIDAC
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An inspiring summer school on computing at the University of
Pennsylvania´s Moore School of Electrical Engineering stimulated construction
of stored-program computers at universities and research institutions. This
free, public set of lectures inspired the EDSAC, BINAC, and, later, IAS
machine clones like the AVIDAC. Here, Warren Kelleher completes the wiring of
the arithmetic unit components of the AVIDAC at Argonne National Laboratory.
Robert Dennis installs the inter-unit wiring as James Woody Jr. adjusts the
deflection control circuits of the memory unit.
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1948
IBM´s SSEC
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IBM´s Selective Sequence Electronic Calculator computed
scientific data in public display near the company´s Manhattan headquarters.
Before its decommissioning in 1952, the SSEC produced the moon-position tables
used for plotting the course of the 1969 Apollo flight to the moon.
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1949
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Wilkes with the EDSAC
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Maurice Wilkes assembled the EDSAC, the first practical
stored-program computer, at Cambridge University. His ideas grew out of the
Moore School lectures he had attended three years earlier.
For programming the EDSAC, Wilkes established a library of short programs called subroutines stored on punched paper tapes.
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Manchester Mark I
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The Manchester Mark I computer functioned as a complete system
using the Williams tube for memory. This University machine became the
prototype for Ferranti Corp.´s first computer.
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1950
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ERA 1101 drum memory
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Engineering
Research Associates of Minneapolis built the ERA 1101, the first commercially
produced computer; the company´s first customer was the U.S. Navy. It held 1
million bits on its magnetic drum, the earliest magnetic storage devices.
Drums registered information as magnetic pulses in tracks around a metal
cylinder. Read/write heads both recorded and recovered the data. Drums
eventually stored as many as 4,000 words and retrieved any one of them in as
little as five-thousandths of a second.
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SEAC
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The
National Bureau of Standards constructed the SEAC (Standards Eastern
Automatic Computer) in Washington as a laboratory for testing components and
systems for setting computer standards. The SEAC was the first computer to
use all-diode logic, a technology more reliable than vacuum tubes, and the
first stored-program computer completed in the United States. Magnetic tape
in the external storage units (shown on the right of this photo) stored
programming information, coded subroutines, numerical data, and output.
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SWAC
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The
National Bureau of Standards completed its SWAC (Standards Western Automatic
Computer) at the Institute for Numerical Analysis in Los Angeles. Rather than
testing components like its companion, the SEAC, the SWAC had an objective of
computing using already-developed technology.
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Pilot ACE
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Alan
Turing´s philosophy directed design of Britain´s Pilot ACE at the National
Physical Laboratory."We are trying to build a machine to do all kinds of
different things simply by programming rather than by the addition of extra
apparatus," Turing said at a symposium on large-scale digital
calculating machinery in 1947 in Cambridge, Mass.
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1951
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MIT Whirlwind
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MIT´s Whirlwind debuted on Edward R. Murrow´s "See It
Now" television series. Project director Jay Forrester described the
computer as a "reliable operating system," running 35 hours a week
at 90-percent utility using an electrostatic tube memory.
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LEO
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England´s first commercial computer, the Lyons Electronic
Office, solved clerical problems. The president of Lyons Tea Co. had the
computer, modeled after the EDSAC, built to solve the problem of daily scheduling
production and delivery of cakes to the Lyons tea shops. After the success of
the first LEO, Lyons went into business manufacturing computers to meet the
growing need for data processing systems.
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UNIVAC I
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The UNIVAC I delivered to the U.S. Census Bureau was the first
commercial computer to attract widespread public attention. Although
manufactured by Remington Rand, the machine often was mistakenly referred to
as the "IBM UNIVAC." Remington Rand eventually sold 46 machines at
more than $1 million each.F.O.B. factory $750,000 plus $185,000 for a high
speed printer.
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1952
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Los Alamos MANIAC
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John
von Neumann´s IAS computer became operational at the Institute for Advanced
Studies in Princeton, N.J. Contract obliged the builders to share their
designs with other research institutes. This resulted in a number of clones:
the MANIAC at Los Alamos Scientific Laboratory, the ILLIAC at the University
of Illinois, the Johnniac at Rand Corp., the SILLIAC in Australia, and
others.
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1953
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IBM 701
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IBM
shipped its first electronic computer, the 701. During three years of
production, IBM sold 19 machines to research laboratories, aircraft
companies, and the federal government.
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1954
1959
IBM STRETCH
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IBM´s
7000 series mainframes were the company´s first transistorized computers. At
the top of the line of computers — all of which emerged significantly faster
and more dependable than vacuum tube machines — sat the 7030, also known as
the "Stretch." Nine of the computers, which featured a 64-bit word
and other innovations, were sold to national laboratories and other
scientific users. L. R. Johnson first used the term "architecture"
in describing the Stretch.
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1960
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DEC PDP-1
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The
precursor to the minicomputer, DEC´s PDP-1 sold for $120,000. One of 50
built, the average PDP-1 included with a cathode ray tube graphic display,
needed no air conditioning and required only one operator. It´s large scope
intrigued early hackers at MIT, who wrote the first computerized video game,
SpaceWar!, for it. The SpaceWar! creators then used the game as a standard
demonstration on all 50 computers.
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1961
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IBM 1401
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According
to Datamation magazine, IBM had an 81.2-percent share of the computer market
in 1961, the year in which it introduced the 1400 Series. The 1401 mainframe,
the first in the series, replaced the vacuum tube with smaller, more reliable
transistors and used a magnetic core memory.
Demand called for more than 12,000 of the 1401 computers, and the machine´s success made a strong case for using general-purpose computers rather than specialized systems. |
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1962
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Wes Clark with LINC
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The
LINC (Laboratory Instrumentation Computer) offered the first real time
laboratory data processing. Designed by Wesley Clark at Lincoln Laboratories,
Digital Equipment Corp. later commercialized it as the LINC-8.
Research faculty came to a workshop at MIT to build their own machines, most of which they used in biomedical studies. DEC supplied components. |
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1964
IBM System/360
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IBM
announced the System/360, a family of six mutually compatible computers and
40 peripherals that could work together. The initial investment of $5 billion
was quickly returned as orders for the system climbed to 1,000 per month
within two years. At the time IBM released the System/360, the company was
making a transition from discrete transistors to integrated circuits, and its
major source of revenue moved from punched-card equipment to electronic
computer systems.
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CDC 6600
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CDC´s
6600 supercomputer, designed by Seymour Cray, performed up to 3 million
instructions per second — a processing speed three times faster than that of
its closest competitor, the IBM Stretch. The 6600 retained the distinction of
being the fastest computer in the world until surpassed by its successor, the
CDC 7600, in 1968. Part of the speed came from the computer´s design, which
had 10 small computers, known as peripheral processors, funneling data to a
large central processing unit.
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1965
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DEC PDP-8
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Digital
Equipment Corp. introduced the PDP-8, the first commercially successful
minicomputer. The PDP-8 sold for $18,000, one-fifth the price of a small IBM
360 mainframe. The speed, small size, and reasonable cost enabled the PDP-8
to go into thousands of manufacturing plants, small businesses, and
scientific laboratories.
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1966
ILLIAC IV
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The
Department of Defense Advanced Research Projects Agency contracted with the
University of Illinois to build a large parallel processing computer, the
ILLIAC IV, which did not operate until 1972 at NASA´s Ames Research Center.
The first large-scale array computer, the ILLIAC IV achieved a computation
speed of 200 million instructions per second, about 300 million operations per
second, and 1 billion bits per second of I/O transfer via a unique
combination of parallel architecture and the overlapping or
"pipe-lining" structure of its 64 processing elements.
This photograph shows one of the ILLIAC´s 13 Burroughs disks, the debugging computer, the central unit, and the processing unit cabinet with a processing element. |
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HP-2115
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Hewlett-Packard
entered the general purpose computer business with its HP-2115 for
computation, offering a computational power formerly found only in much
larger computers. It supported a wide variety of languages, among them BASIC,
ALGOL, and FORTRAN.
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1968
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Ed deCastro and Nova
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Data
General Corp., started by a group of engineers that had left Digital
Equipment Corp., introduced the Nova, with 32 kilobytes of memory, for
$8,000.
In the photograph, Ed deCastro, president and founder of Data General, sits with a Nova minicomputer. The simple architecture of the Nova instruction set inspired Steve Wozniak´s Apple I board eight years later. |
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Apollo Guidance Computer
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The
Apollo Guidance Computer made its debut orbiting the Earth on Apollo 7. A
year later, it steered Apollo 11 to the lunar surface. Astronauts
communicated with the computer by punching two-digit codes and the
appropriate syntactic category into the display and keyboard unit.
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1971
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Kenbak-1
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The
Kenbak-1, the first personal computer, advertised for $750 in Scientific
American. Designed by John V. Blankenbaker using standard medium-scale and
small-scale integrated circuits, the Kenbak-1 relied on switches for input
and lights for output from its 256-byte memory. In 1973, after selling only
40 machines, Kenbak Corp. closed its doors.
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1972
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HP-35
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Hewlett-Packard
announced the HP-35 as "a fast, extremely accurate electronic
slide rule" with a solid-state memory similar to that of a
computer. The HP-35 distinguished itself from its competitors by its ability
to perform a broad variety of logarithmic and trigonometric functions, to
store more intermediate solutions for later use, and to accept and display
entries in a form similar to standard scientific notation.
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1973
TV Typewriter
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The
TV Typewriter, designed by Don Lancaster, provided the first display of
alphanumeric information on an ordinary television set. It used $120 worth of
electronics components, as outlined in the September 1973 issue of Radio
Electronics. The original design included two memory boards and could
generate and store 512 characters as 16 lines of 32 characters. A 90-minute
cassette tape provided supplementary storage for about 100 pages of text.
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Micral
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The
Micral was the earliest commercial, non-kit personal computer based on a
micro-processor, the Intel 8008. Thi Truong developed the computer and
Philippe Kahn the software. Truong, founder and president of the French
company R2E, created the Micral as a replacement for minicomputers in
situations that didn´t require high performance. Selling for $1,750, the
Micral never penetrated the U.S. market. In 1979, Truong sold Micral to Bull.
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1974
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Xerox Alto
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Researchers
at the Xerox Palo Alto Research Center designed the Alto — the first work
station with a built-in mouse for input. The Alto stored several files
simultaneously in windows, offered menus and icons, and could link to a local
area network. Although Xerox never sold the Alto commercially, it gave a
number of them to universities. Engineers later incorporated its features
into work stations and personal computers.
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Scelbi 8H
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Scelbi
advertised its 8H computer, the first commercially advertised U.S. computer
based on a microprocessor, Intel´s 8008. Scelbi aimed the 8H, available both
in kit form and fully assembled, at scientific, electronic, and biological
applications. It had 4 kilobytes of internal memory and a cassette tape, with
both teletype and oscilloscope interfaces. In 1975, Scelbi introduced the 8B
version with 16 kilobytes of memory for the business market. The company sold
about 200 machines, losing $500 per unit.
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1975
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MITS Altair
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The
January edition of Popular Electronics featured the Altair 8800 computer kit,
based on Intel´s 8080 microprocessor, on its cover. Within weeks of the
computer´s debut, customers inundated the manufacturing company, MITS, with
orders. Bill Gates and Paul Allen licensed BASIC as the software language for
the Altair. Ed Roberts invented the 8800 — which sold for $297, or $395 with
a case — and coined the term "personal computer." The machine came
with 256 bytes of memory (expandable to 64K) and an open 100-line bus
structure that evolved into the S-100 standard. In 1977, MITS sold out to
Pertec, which continued producing Altairs through 1978.
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Felsenstein´s VDM
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The
visual display module (VDM) prototype, designed in 1975 by Lee Felsenstein,
marked the first implementation of a memory-mapped alphanumeric video display
for personal computers. Introduced at the Altair Convention in Albuquerque in
March 1976, the visual display module allowed use of personal computers for
interactive games.
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Tandem-16
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Tandem
computers tailored its Tandem-16, the first fault-tolerant computer, for
online transaction processing. The banking industry rushed to adopt the
machine, built to run during repair or expansion.
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1976
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Apple-1, signed by Steve Wozniak
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Steve
Wozniak, a young American electronics expert, designed the Apple-1, a
single-board computer for hobbyists. With an order for 50 assembled systems
from Mountain View, California computer store The Byte Shop in hand, he and
best friend Steve Jobs started a new company, naming it Apple Computer, Inc.
In all, about 200 of the boards were sold before Apple announced the
follow-on Apple II a year later as a ready-to-use computer for consumers, a
model which sold in the millions.
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Cray I
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The
Cray I made its name as the first commercially successful vector processor.
The fastest machine of its day, its speed came partly from its shape, a C,
which reduced the length of wires and thus the time signals needed to travel
across them.
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1977
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Commodore PET
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The
Commodore PET (Personal Electronic Transactor) — the first of several
personal computers released in 1977 — came fully assembled and was
straightforward to operate, with either 4 or 8 kilobytes of memory, two
built-in cassette drives, and a membrane "chiclet" keyboard.
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Apple II
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The
Apple II became an instant success when released in 1977 with its printed
circuit motherboard, switching power supply, keyboard, case assembly, manual,
game paddles, A/C powercord, and cassette tape with the computer game
"Breakout." When hooked up to a color television set, the Apple II
produced brilliant color graphics.
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TRS-80
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In
the first month after its release, Tandy Radio Shack´s first desktop computer
— the TRS-80 — sold 10,000 units, well more than the company´s projected
sales of 3,000 units for one year. Priced at $599.95, the machine included a
Z80 based microprocessor, a video display, 4 kilobytes of memory, BASIC,
cassette storage, and easy-to-understand manuals that assumed no prior
knowledge on the part of the consumer.
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1978
VAX 11/780
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The
VAX 11/780 from Digital Equipment Corp. featured the ability to address up to
4.3 gigabytes of virtual memory, providing hundreds of times the capacity of
most minicomputers.
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1979
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Advertisment for Atari 400 and 800 computers
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Atari
introduces the Model 400 and 800 Computer. Shortly after delivery of the
Atari VCS game console, Atari designed two microcomputers with game
capabilities: the Model 400 and Model 800. The two machines were built with
the idea that the 400 would serve primarily as a game console while the 800
would be more of a home computer. Both sold well, though they had technical
and marketing problems, and faced strong competition from the Apple II,
Commodore PET, and TRS-80 computers.
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1981
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IBM
introduced its PC, igniting a fast growth of the personal computer market.
The first PC ran on a 4.77 MHz Intel 8088 microprocessor and used Microsoft´s
MS-DOS operating system.
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Osborne I
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Adam
Osborne completed the first portable computer, the Osborne I, which weighed
24 pounds and cost $1,795. The price made the machine especially attractive,
as it included software worth about $1,500. The machine featured a 5-inch
display, 64 kilobytes of memory, a modem, and two 5 1/4-inch floppy disk
drives.
In April 1981, Byte Magazine Editor in Chief Chris Morgan mentioned the Osborne I in an article on "Future Trends in Personal Computing." He wrote: "I recently had an opportunity to see the Osborne I in action. I was impressed with it´s compactness: it will fit under an airplane seat. (Adam Osborne is currently seeking approval from the FAA to operate the unit on board a plane.) One quibble: the screen may be too small for some people´s taste." |
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Apollo DN100
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Apollo
Computer unveiled the first work station, its DN100, offering more power than
some minicomputers at a fraction of the price. Apollo Computer and Sun
Microsystems, another early entrant in the work station market, optimized
their machines to run the computer-intensive graphics programs common in
engineering.
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1982
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The
Cray XMP, first produced in this year, almost doubled the operating speed of
competing machines with a parallel processing system that ran at 420 million
floating-point operations per second, or megaflops. Arranging two Crays to
work together on different parts of the same problem achieved the faster
speed. Defense and scientific research institutes also heavily used Crays.
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Early Publicity still for the Commodore 64
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Commodore
introduces the Commodore 64. The C64, as it was better known, sold for $595,
came with 64KB of RAM and featured impressive graphics. Thousands of software
titles were released over the lifespan of the C64. By the time the C64 was
discontinued in 1993, it had sold more than 22 million units and is
recognized by the 2006 Guinness Book of World Records as the greatest selling
single computer model of all time.
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1983
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Apple
introduced its Lisa. The first personal computer with a graphical user
interface, its development was central in the move to such systems for personal
computers. The Lisa´s sloth and high price ($10,000) led to its ultimate
failure.
The Lisa ran on a Motorola 68000 microprocessor and came equipped with 1 megabyte of RAM, a 12-inch black-and-white monitor, dual 5 1/4-inch floppy disk drives and a 5 megabyte Profile hard drive. The Xerox Star — which included a system called Smalltalk that involved a mouse, windows, and pop-up menus — inspired the Lisa´s designers. |
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Compaq PC clone
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Compaq
Computer Corp. introduced first PC clone that used the same software as the
IBM PC. With the success of the clone, Compaq recorded first-year sales of
$111 million, the most ever by an American business in a single year.
With the introduction of its PC clone, Compaq launched a market for IBM-compatible computers that by 1996 had achieved a 83-percent share of the personal computer market. Designers reverse-engineered the Compaq clone, giving it nearly 100-percent compatibility with the IBM. |
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1984
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Apple Macintosh
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Apple
Computer launched the Macintosh, the first successful mouse-driven computer
with a graphic user interface, with a single $1.5 million commercial during
the 1984 Super Bowl. Based on the Motorola 68000 microprocessor, the
Macintosh included many of the Lisa´s features at a much more affordable
price: $2,500.
Apple´s commercial played on the theme of George Orwell´s "1984" and featured the destruction of Big Brother with the power of personal computing found in a Macintosh. Applications that came as part of the package included MacPaint, which made use of the mouse, and MacWrite, which demonstrated WYSIWYG (What You See Is What You Get) word processing. |
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IBM PC Jr.
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IBM
released its PC Jr. and PC-AT. The PC Jr. failed, but the PC-AT, several
times faster than original PC and based on the Intel 80286 chip, claimed
success with its notable increases in performance and storage capacity, all
for about $4,000. It also included more RAM and accommodated high-density
1.2-megabyte 5 1/4-inch floppy disks.
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1985
Amiga 1000 with Seiko Music Keyboard
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The
Amiga 1000 is released. Commodore’s Amiga 1000 sold for $1,295 dollars
(without monitor) and had audio and video capabilities beyond those found in
most other personal computers. It developed a very loyal following and add-on
components allowed it to be upgraded easily. The inside of the case is
engraved with the signatures of the Amiga designers, including Jay Miner as
well as the paw print of his dog Mitchy.
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1986
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Connection Machine
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Daniel
Hillis of Thinking Machines Corp. moved artificial intelligence a step
forward when he developed the controversial concept of massive parallelism in
the Connection Machine. The machine used up to 65,536 processors and could
complete several billion operations per second. Each processor had its own
small memory linked with others through a flexible network that users could
alter by reprogramming rather than rewiring.
The machine´s system of connections and switches let processors broadcast information and requests for help to other processors in a simulation of brainlike associative recall. Using this system, the machine could work faster than any other at the time on a problem that could be parceled out among the many processors. |
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IBM
and MIPS released the first RISC-based workstations, the PC/RT and
R2000-based systems. Reduced instruction set computers grew out of the
observation that the simplest 20 percent of a computer´s instruction set does
80 percent of the work, including most base operations such as add, load from
memory, and store in memory.
The IBM PC-RT had 1 megabyte of RAM, a 1.2-megabyte floppy disk drive, and a 40-megabyte hard drive. It performed 2 million instructions per second, but other RISC-based computers worked significantly faster. |
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1987
IBM PS/2
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IBM
introduced its PS/2 machines, which made the 3 1/2-inch floppy disk drive and
video graphics array standard for IBM computers. The first IBMs to include
Intel´s 80386 chip, the company had shipped more than 1 million units by the
end of the year. IBM released a new operating system, OS/2, at the same time,
allowing the use of a mouse with IBMs for the first time.
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1988
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NeXT
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Apple
cofounder Steve Jobs, who left Apple to form his own company, unveiled the
NeXT. The computer he created failed but was recognized as an important
innovation. At a base price of $6,500, the NeXT ran too slowly to be popular.
The significance of the NeXT rested in its place as the first personal computer to incorporate a drive for an optical storage disk, a built-in digital signal processor that allowed voice recognition, and object-oriented languages to simplify programming. The NeXT offered Motorola 68030 microprocessors, 8 megabytes of RAM, and a 256-megabyte read/write optical disk storage. |
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Generations of Computers
1.
First Generation computers
The first generation computers
were employed during the period 1940 – 1956. These computers used the Vacuum
tubes technology for calculation as well as for storage and control
purposes. The input and output medium for first generation computers was the punched
card and printout respectively.
The following are the two major advantages
of first generation computers.
- These computers were the fastest computing devices for their times.
- These computers were able to execute complex mathematical problems in an efficient manner.
Following are some of the
disadvantages of first generation computers;
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