A Brief History of Computers – For Candidates of Computer Operators

A Brief History of Computers – For Candidates of Computer Operators

Trying to trace the history of computers, how far should we go? Computer Science is the youngest discipline among human repository of knowledge. We know, the Internet became popular among generalpublic since 1990s; Mark I, the first computer, was built in 1944; computers have never gone earlier than 20th century?

That’s true, but, because computers are elegant devices for calculation, and if we skip the development of calculating devices, we’ll just puzzle how computers came into existence! And to understand how these devices emerged, you should know the need to calculate and count. Oh! ‘the counting devices‘? How did people start to count?

It’s strange at first to see every book on history of computers points to the ancient times – the time when mankind just developed from Stone Age. Uhh? That’s the beginning of mankind! Does the history of computers go that distant? Yes.

The First Problem – Counting

Life in jungle must be enjoying. Though, they did not have luxury of materials, their brain must be free from all the tensions of today’s world. All they cared was food and shelter. I wish Eve[1] had never eaten that apple!

The quest for easy food drove mankind into the agricultural age. People started to possess properties. When there is something you possess, you need to remember the quantity, type and so on. How many sheep do I have? How could a man express a quantity? Numbers were not invented yet!

Knots in vine and ropes, notches in sticks, scratches made on rocks must be the first counting aid for people at that time. Later on, those scratches on rocks and drawings on ground must have given a way to develop numbers.

Guess, what after the numbers came into existence? Obviously, the need to add and subtract them!

Mechanical Devices – Counting and Calculating

In this section we will learn about the counting and calculating devices that contribute a way through for the development of modern day computers.

Abacus – The first known calculating device

Abacus[2] is a simple wooden box with beads strung which are moved towards the mid-bar[3] 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 inventedLogarithm[4] – 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

Photo by The Last Cookie 

Slide Rule was invented by William Oughtred 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.

Pascal’s Adding Machine – the Pascaline

Photo by marc kjerland 

17 Century was the most fertile for devising different calculating equipment. Blaise Pascal, at an age of 19 years, designed an adding machine to find the sum of numbers. The machine resulted as his effort to help his father. Pascal’s father worked in tax office and in every evening he had to calculate the sum of collection throughout the day.

It was in 1642 Pascal developed Pascaline which could be used to add, subtract, multiply and divide the numbers by dialing wheels.

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

Photo by Doug Letterman 

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:

ü  Using binary digits to represent all numbers and data

ü  Performing all calculations using electronics rather than wheels, ratchets, or mechanical switches

ü  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

Photo by Erika Hall 

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.

Note: In abbreviation the character ‘C’ in these computers stands for ‘Computer’ or ‘Calculator’. Consider both as correct.

Device	Inventor	Date	Specialty
ENIAC	J.P. Eckert & John Mauchly	1946	First General Purpose Electronic Digital Computer

EDVAC – Electronic Discrete Variable Automatic computer

Photo by angelcalzado 

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!

EDVAC was developed by John Mauchly and John Presper Eckert in 1949 with the help of John von Neumann.

Device	Inventor	Date	Specialty
EDVAC	J.P. Eckert & John Mauchly	1949	Stored Program Computer

EDSAC – Electronic Delay Storage Automatic Computer

Photo by Erika Hall 

EDSAC (Electronic Delay Storage Automatic Calculator) was an early British computer (one of the first computers to be created). The machine, having been inspired by John von Neumann’s seminal EDVAC report, was constructed by Professor Sir Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England.

EDSAC was the world’s first practical stored program electronic computer, although not the first stored program computer (that honor goes to the Small-Scale Experimental Machine).

Device	Inventor	Date	Specialty
EDSAC	Sir Maurice Wilkes	1949	The first Practical Stored Program Computer

UNIVAC – Universal Automatic Computer

Photo by Bernt Rostad 

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