Evolution of Computers

Introduction

Thousands of years ago, people used to keep a count of numbers by using bones and stones. As the need to do large calculations grew, people of calculations fast. The earliest known device used to do calculations is Abacus. To develop a calculating device from the preliminary Abacus to today' most advanced computers, efforts of many people were involved. As a result different machines were developed. Let us learn about some of these developments which led to the present from of computers.

Abacus

An abacus is a calculating device, often constructed as a wooden frame with beads sliding on wires. The word abacus was derived from the Arabic word 'abaq' which means dust. The first abacus was simply a sand table. The Chines abacus is typically around 20 cm (inches) tall and it comes in various widths depending on the application. There are two beads on each rob in the upper deck and five beads each in the lower deck. The beads are usually round in shape and made of hard wood. The beads are counted by moving them up or down.

Napier's Bone

Napier's bone was invented by John Napier in 1617. It was a small instrument made of the strips of bones so it is named as Napier's bone. It was used for the calculation of complex multiplication. John Napier also played an important role in the development of logarithms, which helped to develop 'Slide rule'.

Slide rule

In 1620, William Oughtred, an English mathematician invented the first analog device called the slide rule. The concept of logarithm was used in this device. It has two marked rulers, one of which could slide over the other and once properly aligned would give the user the required product or quotient.

Pascaline

Blaise Pascal invented a mechanical calculator in 1642 called the pascaline to help his father who was a tax collector. The pascaline had dials to deal with numbers up to 9,999,999. It was made with the arrangement of wheels, gears and windows for the display of numbers. The pascaline could only add and subtract numbers.

Stepped Reckoner

Gottfried Wilhelm Von Leibniz was a German philosopher, mathematician and statesman. He is regarded one of the supreme intellects of the 7^th century. He invented a mechanical calculator called Stepped Reckoner in 1694. This was invented on the same principal as Pascal's mechanical calculator, except that there was a system of shift mechanism, operating through a series of soldiers. This device could perform addition, subtraction, multiplication, division and calculation of square root.

Jacquard's Loom

The Jackquard's Loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801. The idea of Jackquard was to use punched cards to control the weaving patterns. It gave the idea for the modern mechanism on punched cards and the use of binary number system.

Charles Babbage's Engines

Charles Babbage is a mathematician at Cambridge University. He develop and demonstrated a working of a mathematical computer called Difference Engine in 1822. The machine was designed to calculate mathematical tables. It was accurate and able to do calculations up to twenty decimal places mechanically. The project stopped when Babbage's funds ran out. In 1833-34, Charles Babbage designed another machine named Analytical Engine that could be programmed to solve particular problems. This machine had five units: input, output, store, mill and control, which are similar to the units of a modern computer. Thus, Charles Babbage is regarded as the "Father of the computer". Due to lack of technology, the Analytical Engine was never completed.

Lady Augusta Ada

Lady Augusta Ada, helped to program the analytical engine. Since the machine was not built, her programs were never tested. But she was really the world's first programmer for devising a suitable binary number system for writing programs. The high-level programming language developed by the US Department of Defence was named "ADA" in her honour in 1979.

Hollerith's Tabulator

in 1887, Dr. Herman Hollerith, an American census statistician with U.S. Census Bereau, invented a punched-card tabulating machine. This machine was used to process the data collected in the census of the United States. It consisted of a tabulator, a sorter with compartments electronically controlled by the tabulator's counter and the device used to punch data onto cards. This tabulator could read the presence or absence of holes in the cards by using spring-mounted nails that passed through the holes to make electrical connections. In 1896, Hollerith established tabulating Machine Company, which was later named IBM (International Business Machine) Corporation.

Harvard Mark I

Harvard Mark I was one of the earliest electronic computers. Howard Aiken of Harvard University designed it in collaboration with IBM Corporation in 1937-1944. The mark I was 8 feet high, 51 feet long, and weighed nearly 5 tons. The mark was used for military purposes, including development of the atomic bomb. It was also known as the Harvard-IBM Automatic Sequence Controlled Computer (ASCC).

AtanasoftBerry Computer (ABC)

Dr. john Vincent Atanasoff and Clifford E. Berry developed Atanasoff Berry Computer in 1938-42 at lowa State University. It used 45 vacuum tubes for internal logic and capacitors for storage. It is considered as the first computing machine, which introduced the idea of binary arithmetic, regenerative memory and logic circuits. This machine laid the foundation for the development of electronic digital computer.

Electronic Numerical Integrator and Calculator (ENIAC)

Electric Numeric Integrator and Calculator (ENIAC) was designed by John Eckert and John Mauchly in 1946. It was the first electronic computer. It contained 18000 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million hand-soldered joints. It weighed nearly 30 tons and consumed 160 kw of power. Input was possible from an IBM card reader while an IBM punch card was used for output.

Electronic Discrete Variable Automatic Computer (EDVAC)

John Mauchly and J.P. Eckert also proposed the development of EDVAC (Electronic Discrete Variable Automatic Computer). The conceptual design for EDVAC was completed by 1946 and it came into existence in 1949. It was one of the earliest electronic computers to use the stored program concept introduced by John Von Neumann. Unlike the ENIAC, it used binary number rather than decimal. The University of Pennsylvania built the EDVAC for the U.S. Army's Ballistics Research Laboratory at the Aberdeen Proving Ground. EDVAC had almost 6,000 vacuum tubes and 12,000 diodes. It consumed 56 kw of power. It covered 490 ft² (45.5m²) of floor and weighed 17,300 lb (7,850 kg).

Electronic Delay Storage Automatic Calculator (EDSAC)

EDSAC (Electronic Delay Storage Automatic Calculator) was develop by a group of scientists, headed by professor Maurice Wikes at Cambridge University, England, in 1949. It was also based on the stored program concept and one of the first to use binary digits. The input and output were provided by a paper tape. It could do about 700 additions per second and 200 multiplications per second. The machine occupied a room, which measured 5/4 meters.

Universal Automatic Computer (UNIVAC)

UNIVAC (Universal Automatic Computer) was the first commercially general purpose electronic computer. John Eckert and John Mauchly at the Moore school of engineering, Pennsylvania developed it in 1951. It was used for analysis of 1952 Presidential Election in the United States. It was 8 ft high, 15 ft long and weighed 5 tons. It contained 5600 tubes, 18000 crystal diodes, and 300 relays. A magnetic tape was used for data input and output.