Transcript History of Computers

History of Computers
•
•
•
•
•
•
•
•
Early Developments In Data Processing
Punched Card Equipments
Digital Computers
Computer Generations
Types Of Computers
Types of Input Devices
Types of Output Devices
Storage Devices
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
1
Early Developments in Data
Processing
• The Abacus
– Developed by Greeks and Romans with
significant contribution from Chinese.
– Additions and subtractions are done by
changing the position of beads.
– Significant conceptual contribution of the
Abacus is the use of position to represent value.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
2
• Pascal’s Machine
– Blaise Pascal, a French Mathematician and
Philosopher, invented in 1642 a Mechanical
Calculator.
– It was a gear driven machine capable of
addition, subtraction and multiplication.
– Manipulations were performed by rotating
wheels.
– Automatic carry was the significant
contribution from Pascal’s machine.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
3
• Modifications to Pascal’s Machine
– In 1671 German Mathematician and
Philosopher Gottfried von Leibnitz improved
Pascal’s design.
– This machine was capable of addition,
subtraction, multiplication and division. It was
also able to calculate square roots.
– It consisted of cylindrical drum with nine teeth
along its surface. The teeth varied in length, and
when the drum rotated, some of them engaged a
sliding gear on the axle.
– This gear principle was employed in many
mechanical calculators till 1960’s.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
4
• Jacquard’s Loom
– In 1801 a Frenchman named Joseph Jacquard
prepared a loom that was controlled by holes in
cardboard punched cards.
– The design for woven fabrics was represented
by a series of holes punched in the card.
– By sequencing the cards, the loom could
produce a large number of patterns and designs.
– Jacquard’s punched cards were a ‘Program’ for
the loom. They stored various fabric designs.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
5
• Babbage’s Engines
– In 1812 Charles Babbage, an English mathematician
found that certain principals from Jacquard’s loom
could be used in numerical computation.
– Babbage devised computing steps that could be stored
in advance of computation. He thus developed the
concept of the stored program for data processing. He is
generally recognized as the first person to propose the
concept of computer.
– Babbage designed an analytical engine with four major
components viz. input and output devices, an arithmetic
unit to perform the calculations and a memory to store
intermediate calculations.
– Unfortunately he didn’t succeed in building this
machine.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
6
Punched Card Equipments
• Metcalfe’s Cards
– In 1870’s Lt Henry Metcalf, at the Frankfor Arsenal in
Philadelphia, transferred some of the accounting
records from ledgers to cards.
– These cards were similar to index cards normally used
by librarians.
– The decks of cards could be manually sorted,
summarized and manipulated to meet the information
needs of the management.
– This system required a sophisticated coding scheme, a
well-defined unit record and a system design that
specified the flow of data.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
7
• Hollerith’s Punched Cards
– In late 19th century US govt beganto encounter
problems in data processing. It took 7 years to compile
the statistics from the 1880 census.
– Hollerith designed a device called tabulating machine.
It used machine readable punched cards. His machine
reduced tabulating time on 1890 census one-eighth the
time required by the old methods.
– In 1911, Hollerith’s Tabulating Machine Company
merged with the International Time Recording
Company, the Dayton Seale Company, and the Bundy
Manufacturing Corp to form Computing-TabulatingRecording Company (CTR). In 1924, CTR was
renamed as International Business Machine Corp.
(IBM).
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
8
• Powers’s Punched Cards
– James Powers, an engineer who worked for the
US Census Bureau, produced several
refinements of Hollerith’s machine and
patented a punched-card machine in 1908.
– Powers also developed a sorting machine and
tabulators that were employed in 1910 US
census.
– He later formed Sperry Rand Corporation,
which produced UNIVAC computers.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
9
• General Scenario in 1940s
– Until the beginning of World War II, only two
companies in US were involved in the Punched
Card data processing business viz. IBM that
used 80 column Holerith card and Sperry Rand
Corporation that used 90 column Powers card.
– The war created great demands for high speed
calculating equipment.
– Developments in long-range artillery, aircraft
and eventually the atomic bomb required
machines that could calculate at very high
speed.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
10
Digital Computers
• Harvard Mark I
– In 1937, Howard Aiken of Harvard University, began
work on the design of a fully automatic calculating
machine in collaboration with the IBM Corporation.
Howard’s aim was to develop a machine to help him in
the solution of complex differential equations.
– In May 1944, the design became a reality. In August
1944, ‘Harvard Mark I’ was donated to Harvard
University. It was initially used for classified work for
the US Navy.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
11
– It had taken technology over a century to catch up with
the ideas first mooted by Charles Babbage. But once
having achieved this a phenomenal rate of development
followed.
– The Mark I or Automatic Sequence Controlled
Calculator, was complex in design and huge in size.
– Physically the machine measured 51 feet in length and
8 feet in height. It is said to have contained threequarters of a million parts. It used more than five
hundred miles of wire.
– It was extremely slow by present day standards.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
12
• ENIAC
– The innovation of very high speed vacuum tube
switching devices led to the first-all electronic
computer, the Electronic Numerical Integrator
and Calculator (ENIAC). It was dedicated on
15th February 1946, only two years after the
Mark I.
– ENIAC was constructed at the Moore School of
Engineering of the University of Pennsylvania.
– In a single hour ENIAC could accomplish
calculations which would have taken Mark I
one week to perform.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
13
• EDVAC
– The Electronic Discrete Variable Automatic
Computer – EDVAC – made use of acoustic
delay lines consisting of tanks of mercury.
– Both the instructions and the numbers to be
used for calculation were stored in the memory
unit.
– Prior to EDVAC, EDSAC (Electronic Delay
Storage Automatic Calculator) which was
developed by British was the first practical
computer to operate with an internally stored
program.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
14
• Manchester Mark I
– It was a small experiment machine built at
Manchester University. It executed its first
program in June 1948.
– Its storage capacity was only 32 words, each of
31 binary digits.
– It was too limited to be of any practical use.
– This project was set up by Professor Newman,
aided by I.J. Good, F.C. Williams and T.
Kilburn.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
15
Computer Generations
• No clear cut pattern of development after EDSAC
& EDVAC has emerged.
• In order to simplify the matters and provide a
framework for the growth of the computer
industry the term of Computer generation was
used.
• Originally, the term ‘generation’ was used to
distinguish between varying hardware
technologies.
• Since 1968, it has been extended to include both
the hardware and the software.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
16
• Size & weight of the earlier computers
prompted magazine Popular Mechanics to say:
• Computers in the future may weigh no more
than 1.5 tons
• In the early years the people who were at the
helm of computer industry were also not aware
of the potential of the computer industry.

"I think there is a world market for maybe
five computers."
-- Thomas Watson, chairman of IBM, 1943
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
17
• First Generation of Computers (1951-1958)
– The first generation of computers was marked by the
use of vacuum tubes for the electronic components and
by the use of either electrostatic tubes (cathode ray
tubes) or mercury delay lines for storage.
– These computers were very expensive. They were quite
large and required special housing.
– The medium of internal storage was magnetic drum.
– Examples of First Generation computers are EDSAC,
EDVAC etc.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
18
• Second Generation Computers (1959-1964)
– The second generation saw the introduction of printed
circuits and the replacement of valves by transistors.
– In comparison with the previous generation they were
smaller in size and generated less heat.
– Internal storage capacity was increased and processor
speeds started to be measured in microseconds
(millionths) rather than milliseconds (thousandths)
– Magnetic core storage was used rather than magnetic
drum.
– Machines started to evolve as series rather than standalone processors.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
19
• Second Generation Computers (Contd.)
– During this period many punch card machines
became popular. The hardware consisted of
•
•
•
•
•
•
Key punch
Verifier
Calculator punch
Tabulator (it was essentially processor and printer)
Sorter
Collator (to merge two batches of cards or to match
two batches of cards)
• Reproducer
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
20
• Second Generation Computers (Contd.)
– In both these generations thousands of separate
components had to be assembled by hand into
functioning circuits. It was cost of labour at this
assembly stage which became increasingly
expensive.
– Introduction of new technology called
Integrated Circuits (IC) made it possible to
reduce the size and to eliminate the labour
costs.
– In 1964 IC s began to be used in computers,
thereby ushering in the the third generation.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
21
• Third Generation Computers (1965-1971)
– The advances over the previous generation were very
significant. It used small-scale integration (SSI)
technique or medium-scale integration (MSI)
technique.
– Further reduction in size.
– The cost performance factor has improved significantly.
– Increased internal core memory capacity.
– Increased emphasis on the use of disk as a backing
store medium and substantially reduced cost per
megabyte.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
22
• Third Generation Computers (Contd.)
– Processor speeds are rated in nanoseconds –
1/1000th of a microsecond.
– Ranges of computers came into being e.g. IBM360, ICL-1900. Models within these ranges
were designed to be upward compatible’
thereby enabling systems developed for the
lower models in the range to move up the line
with limited modification.
– The use of high level languages became
common viz. COBOL, FORTRAN and PL/1.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
23
• Fourth Generation Computers (1971-Present)
– Despite of the continued development in the field of
computers, people from computer industry were still
not able to foresee the future.
– Following are some of the now infamous quotes:
• “But what is it good for?“
Engineer at the Advanced Computing Systems Division of
IBM, 1968, commenting on the microchip.
• “There is no reason anyone would want a computer in their
home”
Ken Olson, president, chairman and founder of Digital
Equipment Corp., 1977
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
24
• Fourth Generation Computers (Contd.)
– It used large-scale integration (LSI) technique.
– The distinguishing marks were the introduction
of standard architecture which provided for
greater mobility of systems, the introduction of
micro-technology and significant software
developments.
– This generation gave rise to the availability of
microcomputers, word processors and
intelligent terminals.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
25
• Fourth Generation Computers (Contd.)
– Further reductions in the size of the hardware.
– Better price/performance.
– Hardware which in many cases will operate in a normal
office or residential environment.
– Semiconductor memory based on the silicon chip used
as core storage. This has led to great expansion in the
amount of memory available typically few megabytes
as against few kilobytes in the previous generation.
– Cheaper and bigger backing storage devices. Typically
single disk drives with capacity of few gigabytes.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
26
• Future Computers
–
–
–
–
–
–
–
Organic chips
Decreasing cost of software
Decreasing cost of hardware
Super and ultra personal computers
Increased miniaturization
Vast performance in the price-performance ratio.
Applications- artificial intelligence, personal robots,
large scale corporate modeling.
– Large storage facility
– High speed
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
27
Types of Computers
•
•
•
•
•
•
•
•
Supercomputers
Mainframes
Midrange Machines/Minicomputers
Workstations
Microcomputers
Laptops
Hand Held Computers
Pen Based Computers
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
28
• Supercomputers
– Supercomputers are fastest and largest
computers available today.
– They have large memories and high processing
speeds. They can process up to a billion
instructions per second.
– Supercomputers are used for processing very
large files and performing large-scale
mathematical calculations.
– Supercomputers have multiple processors to do
parallel processing.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
29
• Supercomputers (Contd)
– Primary disadvantage of supercomputers is
their high cost. The software that runs on them
is also very expensive.
– Main applications that use Supercomputers are
•
•
•
•
•
•
•
Scientific research and R & D
Defense
Geo-science and weather forecasting
Economic and financial modelling
Imaging
Simulatoin
Biological and chemical engineering
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
30
• Mainframes
– Mainframe is a large, general purpose computer with a
large memory and excellent processing capabilities.
– Mainframes, which are frequently organization wide
systems, take their name from ‘main frame’ which once
housed the CPU.
– Mainframes serve many users at the same time.
– One of the main disadvantages of the mainframe is that
it is expensive to purchase, operate and maintain.
Mainframes often require customized software and
highly trained computer personnel to run and operate
them.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
31
• Mainframes (Contd.)
– They are ideal for applications that require
massive computations and large-scale
processing.
– The main applications that use mainframes are
•
•
•
•
•
Financial applications
Payroll
Investment analysis
Weather forecasting
Airline & railway reservations
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
32
• Midrange Machines/Minicomputers
– In the 1970s, Digital Equipment Corporation (DEC)
introduced the concept of a midrange computer, or
minicomputer, called the VAX.
– Microcomputers, which are typical work-group
systems, are small yet powerful multi-user systems with
excellent memory capabilities and processing speeds.
– They are slower than mainframes and often have less
memory.
– The introduction of Minicomputers allowed many
companies that were unable to afford mainframes to
enter the age of computing.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
33
• Workstations
– Workstations lie somewhere between minicomputers
and PCs.
– They can be used by individuals or by groups.
– They are faster and more sophisticated than PCs and are
equipped with a number of productivity tools that
increase their efficiency.
– Advances in microprocessors and sophisticated
software have significantly increased the capabilities of
these machines.
– Some of the popular workstations are
• SPARC stations form Sun Microsystems
• IBM RS/6000
• Hewlett-Packard’s Series 700
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
34
• Microcomputers (PCs)
– PCs are regarded by many as one of the greatest
invention in history.
– Although the memory size and processing capabilities
of microcomputers are less than those of mainframes
and minicomputers, advances in hardware technology
have made the PC a compact, powerful and versatile
machine.
– PCs have given the ability to users to plug in different
hardware and software components and customize their
PCs to meet their own personal requirements.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
35
• Laptops and Notebooks
– Laptops and notebooks provide mobile
computing technology.
– Primary differences between a laptop and a
notebook are size and weight. Notebooks are
smaller than laptops. However,both are are
equipped with powerful microprocessors,
graphics capabilities and adequate memory
size.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
36
• Hand-Held Computers
– Hand-held computers are even smaller than
notebooks.
– They are primarily used to collect field data.
– Common applications where Hand-held
computers are used are:
• Sales Representatives.
• Archaeologists at a dig site.
• Mobile police force in US.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
37
• Pen Based Computing
– Pen base computing refers to portable
computers that use an electronic writing pad
and a light sensitive electronic pen, thus freeing
users from the constraints of a keyboard.
– Pen-based computing is becoming increasingly
popular because many people are comfortable
using a pen.
– It is particularly popular in sales and service
representatives and other people who are often
on the move.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
38
Types of Input Devices
•
•
•
•
•
Keyboard
Scanning Devices
Voice Input Devices
Pointing Devices
Touch-Tone Devices
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
39
• Scanning Devices
– Bar Code Readers
• They have proved to be very valuable as data entry devices for
two reasons viz. The price and product inventory numbers do
not need to be keyed in and the online real-time sales data and
inventory status is always available.
– Optical Mark Readers (OMR)
• It is the simplest form of optical data recording. OMR device
has a high-intensity light inside that is directed in the form of a
beam at the sheets of paper being fed through.
• They come in a variety of sizes and shapes.
• Popular application that uses these devices are different
competitive examinations.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
40
• Scanning Devices (Contd.)
– Typewritten and Typeset-character scanners
• These devices were introduced to help speed up and
reduce the cost of converting typewritten data to
computer usable form.
– Handwritten-Character Readers
• Although the percentage of data recorded by hand
has dropped substantially over the last 50 years,
quite a bit of data is still recorded this way. As OCR
technology advanced, it also became possible to
convert handwritten data into computer usable
forms.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
41
• Scanning Devices (Contd.)
– Magnetic Ink Character Recognition (MICR)
• This technology is mainly used in banking industry.
Advantages of MICR system are human
involvement is minimal and it is fast, automatic and
reliable.
– Smart Cards
• Smart cards were pioneered in the mid 1970s in
France.Smart cards have microchips that can keep
permanent records, which are updated each time the
card is used. They are used in Europe and US to pay
bills, buy merchandise, make phone calls, store
emergency medical information etc.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
42
• Voice Input Devices
– In an effort to increase worker productivity, a
substantial amount of research is being done in
voice recognition.
– These devices convert spoken words into
computer usable form.
– This technology is also used by people who are
not able to use traditional input devices.
– Several voice input units are currently available
for use with PCs.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
43
• Pointing Devices
– Light Pen
• It uses a light-sensitive photoelectric cell to signal screen
position to the computer. Light pens are frequently used by
graphical designers, illustrators and drafting engineers.
– Mouse
• The mouse can be use like a pen or a paintbrush to create
figures and patterns .
– Touch Screen
• Limited amounts of data can be entered via terminal or a PC
that has a touch screen.
– Digitizer
• The digitizing tablets are the working surface. Each is covered
by a grid of many tiny wires that is connected to computer.
Drawings placed over this grid can be traced and entered into
the computers.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
44
Types of Output Devices
• Hard Copy Output Devices
• Softcopy Output Devices
• Voice Output Systems
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
45
• Hard Copy Output Devices
• Letter Quality Printers
– Letter quality printers, also called character printers or
serial because they print one character at a time. It is
normally used for important business letters, memos
and reports.
• Dot-Matrix Printers
– These are also called as serial printers. They have
greater speed and more flexibility.
– The print head of a dot-matrix printer usually has nine
pins. However, high quality dot matrix printers have
print heads with 24 pins.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
46
• Dot-Matrix Printers (Contd.)
– Speed of dot matrix printers ranges from 50 cps
to 400 cps.
• Line Printers
– They are so called because they print a whole
line of characters at one.
– Their speed ranges from 200 to 3,000 lines per
minute.
– Major disadvantages of line printers are noise
and relatively poor image quality.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
47
• Ink-Jet Printers
– Ink-jet printers work in much the same fashion as dot
matrix printers in that they form images or characters
with little dots. However, the dots are formed, not by
hammer like pins, but by tiny droplets of ink. These
printers have speed similar to dot matrix printers.
• Laser Printers
– This technology is much less mechanical than impact
printing, resulting in higher speeds and quieter
operation. The process resembles the operation of a
photocopy machine. The major advantages are high
speed, low noise level and very high image quality.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
48
• Plotters
– A plotter is a specialized output device
designed to produce high-quality graphics in a
variety of colours. Different types of plotters
are available viz. drum plotter, flatbed plotter
and electrostatic plotters. Drum and flatbed
plotters use pens. Electrostatic plotters are
faster than pen plotters and can produce images
of very high resolution.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
49
• Softcopy Output Devices
– Monochrome and Color Monitors
– Liquid Crystal Display (LCD)
• The principal advantages of LCD are low power
consumption, low cost and small size.
• Main disadvantages of LCD are it does not emit
light; as a result the image has very little contrast
and screen is very susceptible to glare, so the
optimum viewing angle is very narrow.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
50
• Gas Plasma Display
– It is the oldest flat screen technology in use.The
main advantages of it are:
• The images are much brighter than on a standard
CRT.
• The resolution is excellent.
• Glare is not a significant problem.
• The screen does not flicker like some CRTs.
– Its main disadvantages are:
• Only a single color is available (reddish orange)
• The technology is expensive.
• It uses a lot of power.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
51
• Voice Output Systems
– Voice output systems are relatively new and can be
used in some situations where traditional display screen
softcopy output is inappropriate.
– Two different approaches to voice output have evolved
viz. speech coding and speech synthesis.
– Speech coding relies on human speech as a reservoir of
sounds to draw from in building the words and phrases
to be output. Speech coding has been used in
applications such as automobiles, toys and games.
– Speech synthesis relies on the use of a set of basic
speech sounds that are created electronically without
the use of a human voice.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
52
Storage Devices
• Magnetic Tapes
• Diskettes
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
53
• Magnetic Tapes
– Faster, more convenient and more cost-effective means
than punched cards
– Magnetic tape is a plastic tape coated with
magnetizable iron oxide.
– A modern tape storage unit can store the equivalent of
more than 2.25 million punched cards.
– It is widely used in minicomputers and mainframe
computers
– Limitations of Magnetic tapes:
• Data recorded on tape can not be practically altered. When
records need to be changed, added, deleted or modified a
completely new tape must be created.
• The data is recorded on the tape sequentially and can be
accessed only sequentially.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
54
• Floppy Disks
– Like magnetic tapes, floppies are made of a
special plastic that can be coated and easily
magnetized.
– The initial diskette introduced by IBM was 8
inches in diameter.
– IBM introduced 5 ¼ inch diskettes in their PCs
in 1981 while Apple introduced 3 ½ inch
diskettes in 1984.
– The capacity of diskettes ranges from 360 KB
to 1.44 MB
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
55
• Hard Disks
– The introduction of high-capacity of hard disks
for PCs solved problems related to limited
storage capacity.
– Hard disk technology was first introduced by
IBM in the early 1970s.
– Hard disks for PCs began to appear in 1980s.
– Initial capacity of Hard Disks for PCs was in
the range of 10MBs.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
56
• Disk Cartridges
– Removable disk cartridges are an alternative to hard
disk units as a form of secondary storage.
– Their capacity is normally lower than hard disk units
but still substantially superior to floppies.
• Cartridge Tape Units
– As high-capacity hard disk units increased in
popularity, the problem of making backup copies of
disk contents became a significant concern.
– This concern prompted the development and refinement
cartridge-tape units.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
57
• CD-ROM / CD-ROM Drive
– The user cannot erase it, change it or write on this disk.
– The user can only read the data.
– Typical storage capacity of CD is 700/800 MB.
• WORM CD (Write Once, Read Many)
– The user cannot erase it or change it
– The user can write the data once.
• CD R/W
– The user can write data many times.
– User can also erase or change the data.
26/07/2003 - Allana
Prepared by Prakash M. Vaidya
58