Historical
development of Computer
Abacus – The first known
calculating device
Abacus is a simple wooden box with beads strung
which are moved towards the mid-bar to perform calculations.
You bring the beads near the bar and count to get result. Obtaining result is
a manual process. Thus Abacus is essentially
a memory aid rather than truly a calculating device. It is generally agreed
that Abacus was invented in China
around 2500 BC.
An Abacus is divided into two parts – heaven, the upper
deck and earth, the lower deck – divided by a mid-bar. On each string there are
two beads on heaven and 5 beads on earth. The value of each bead on heaven is 5
and on earth it is 1. So if you pull one heaven bead and 3 earth bead near the
mid-bar, it represented the number 8.
Napier’s bones
Abacus is about ancient past. When we look upon the
modern history, it is 1614 when John Napier invented Logarithm – a branch of mathematics to multiply
and divide extremely large or small numbers. This is considered the principal
invention of Napier.
In Computer Science what interests us more about Napier’s
invention, in addition to the rule of Logarithm, is Napier’s bones. It is a set of rods (10 rods in a set).
Numbers are carved on each rod and can be used to perform multiplication, division
with the help of logarithm. These rods were made up of bones, and must be the
reason for the name.
Calculation is done by aligning the proper rods against
each other and by inspection.
Slide Rule
Slide Rule was invented by William Ought red towards
1620. This device consists of logarithmic scales where one can slide upon
other. The sliding rule is aligned properly against other scale and a reading
is done through the indicator slide.
Slide rule could be used to perform multiplication and
divisions efficiently.
Leibnitz’s Calculator – The Stepped Reckoner
German philosopher Gottfried Wilhelm von Leibnitz
improved Pascal’s adding machine and made Stepped Reckoner that could even find
square roots. This is the first digital mechanical calculator that
can perform all four basic arithmetic operations – add, subtract, multiply and
divide.
Charles Babbage and his engines
Charles Babbage is considered the father of
modern computers. It is his ideas – the idea of input, mill (processing),
output and storage – the modern computers followed and been successfully
miraculous device! Though he could not complete his Analytical Engine
(conceived in 1830s) due to insufficient funding and technological advancement
of the day, it proved to be a foundation for the birth of computers.
Babbage however completed a working model of
his first machine – The Difference Engine and was awarded by Royal Society.
Difference engine implemented the mechanical memory to store results. It was
based on the difference tables of squares of the number, and thus the name –
Difference Engine.
INTERESTING FACT: Babbage conceived of a
computer 100 years earlier. Howard Aikin builds the first computer Mark I based
on Babbage’s idea in 1944.
Lady Augusta Ada Lovelace – The first programmer
Lady Augusta Ada Lovelace was a great
supporter of Charles Babbage and she convinced him to use binary systems in his
engines. Because she devised a way to program Babbage’s engines, she is
considered the first
programmer.
Ada is the daughter of Lord Byron, a famous
English poet.
US Defense developed a programming language
and named it ADA to honor her contribution
Dr. Herman Hollerith & his
Tabulating Machines
Herman Hollerith invented a tabulating machine for the
census of 1880s. He used punched cards
to code the numbers and feed them into the machine. That’s why he is considered
to be the man to use punched cards practically for the first time. Though
Charles Babbage used punched cards for his analytical engine, it was never
built and Hollerith was successful in designing a machine that could accept
input through punched cards.
Hollerith founded Tabulating Machine Company to build and
sell his products and later on it was merged with some other companies to form
International Business Machine (IBM) Company. IBM is the largest computer
manufacturing company even today.
INTERESTING FACT: Punched cards were originally invented
by Joseph Jacquard, a textile manufacturer. He used them to automate the
weaving loom. These cards were later used by Charles Babbage in his design of
Analytical Engine and Herman Hollerith practically used them for the first time
in his Tabulating Machine.
EXTRA DOZE: Calculating devices such as Abacus,
Slide Rule, and Napier’s bones etc. were very simple machines that could add,
subtract and repeated operation to perform multiplication and division. Though
they appear trivial today, they were great invention of that time.
By mechanical part, it means it works by moving wheels
and bars. Electronic components do not have any moving parts to perform
calculation and can work with the flow of electricity in its circuitry. Because
it does not have moving parts, these devices are very low at failure rate.
Electro Mechanical
Computers
In 1944 the first electro-mechanical computer Mark -I was
built by Howard Aiken with the help of IBM. Mark I, Mark II, and Zues Computers (Z2, Z3) are the examples of
Electro Mechanical Computers. Let’s look at Mark I and Z3 computer here.
Mark I
Mark-I, originally known as IBM Automatic Sequence Controlled Calculator (ASCC),
is the first computer of the world. Mark-I is described as the beginning of the
era of the modern computer. It was built in Harvard University by Howard H.
Aiken.
Mark I was a gigantic computer. It was 51 feet long, 8
feet tall and 2 feet wide which weight 4500 Kg. It could do three additions or
subtractions in a second. A multiplication took six seconds, a division took
15.3 seconds, and a logarithm or a trigonometric function took over one minute.
|
Device
|
Inventor
|
Date
|
Specialty
|
|
Mark – I
|
Howard Aiken
|
1944
|
First Computer
|
Z3 Computer
Apart from Mark I and Mark II computers, there are other
contemporary computers like Z2 and Z3 (designed by Konrad Zuse) on this
category.
The contribution of Zuse was ignored for long due to
political reasons. He was a German Engineer and Computer Pioneer. Zuse
completed his work entirely independently of other leading computer scientists
and mathematicians of his day. Between 1936 and 1945, he was in near-total intellectual
isolation.
Improving the basic Z2 machine, Konrad built the Z3 in
1941. It was a binary 22-bit floating point calculator featuring
programmability with loops but without conditional jumps, with memory and a
calculation unit based on telephone relays.
Zuse’s company (with the Z1, Z2 and Z3) was destroyed in
1945 by an Allied air attack.
Electronic
Computers
In 1947 John Mauchly and J. P. Eckert developed the first
general purpose electronic computer – ENIAC. This begins a new era in computing
history. Apart from ENIAC, ABC, EDVAC and UNIVAC are some early electronic
computers. We will be studying these computers in this section.
Calculating devices were fairly simple aid for human
head. Electromechanical calculators were moderately complex. There were wheels,
drums and bars that rotate and move to produce result. Because they had some
mechanical parts, those devices are called electro-mechanical computers.
Electronic computers, on the other hand, work with the flow of electrons in
its different components. Because electronic components are more reliable and
speedy, electronic computers are very reliable compared to the earlier
computers.
ABC
ABC, the first electronic digital computer,
was invented by John v. Atanasoff and his assistant Clifford Berry and thus the
name Atanasoff Berry Computer (ABC).
Earlier, ENIAC was considered to be the first
electronic computer until in 1973 a U.S. District Court invalidated the ENIAC
patent. Thus, ABC is the first electronic digital computer. However, because ABC
is a special purpose computer and not programmable, ENIAC still is the first
general purpose electronic computer.
It is the ABC that first implements the three
critical features of modern computers:
- Using binary digits to represent
all numbers and data
- Performing all calculations using
electronics rather than wheels, ratchets, or mechanical switches
- Organizing a system in which
computation and memory are separated.
|
Device
|
Inventor
|
Date
|
Specialty
|
|
ABC
|
John v. Atanasoff & Clifford Berry
|
1942
|
First Electronic Digital Computer
|
ENIAC
ENIAC stands for Electrical Numerical Integrator and Calculator. It was developed in 1946 by John Mauchly
and John Presper Eckert.
ENIAC is the first general-purpose electronic digital
computer. It used to be considered the first electronic computer till 1973 when
a U.S. District Court invalidated the ENIAC patent and concluded that the
ENIAC inventors had derived the subject matter of the electronic digital
computer from Atanasoff. Anyway, it is still the first general purpose
electronic computer.
ENIAC used decimal numbering system for its operation and
contained 17,468 vacuum tubes, along with 70,000 resistors, 10,000 capacitors,
1,500 relays, 6,000 manual switches and 5 million soldered joints. It covered
1800 square feet (167 square meters) of floor space, weighed 30 tons, and
consumed 160 kilowatts of electrical power.
|
Device
|
Inventor
|
Date
|
Specialty
|
|
ENIAC
|
J.P.
Eckert & John Mauchly
|
1946
|
First
General Purpose Electronic Digital Computer
|
EDVAC – Electronic Discrete
Variable Automatic computer
Well that’s
it – the name itself includes the word ‘automatic’ like ENIAC used the word
‘electronic’. ENIAC must be excited as it was not depending upon mechanical
components, so, called it ELECTRONIC!
|
Device
|
Inventor
|
Date
|
Specialty
|
|
EDVAC
|
J.P. Eckert
& Jo Mauchly
|
1949
|
Stored
Program Computer
|
UNIVAC – Universal Automatic
Computer
After the
successful development of ENIAC and EDVAC, John Mauchly& J.P. Eckert founded
their own company in 1946 and began to work on the Universal Automatic
computer.
UNIVAC was
the first general purpose commercial computer.
|
Device
|
Inventor
|
Date
|
Specialty
|
|
UNIVAC
|
J.P. Eckert & John Mauchly
|
1951
|
The first general purpose commercial computer
|
