Historical development of computers

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