Introduction to Computers PDF

INTRODUCTION TO COMPUTERS  What is a Computer? A programmable machine that can execute a programmed list of instructions and responds to new inst...

INTRODUCTION TO COMPUTERS  What is a Computer? A programmable machine that can execute a programmed list of instructions and responds to new instructions that are given. This Photo by Unknown Author is licensed under CC BY-NC Manual Computing Devices Abacus ( around 500 BC) Abacus 300 BC (Babylonians)/Salamis Tablet 600 BC Chinese an early aid for mathematical computations it means “dust” (Hebrew) Abacus  Considered as the earliest device for calculation , the abacus is used by the Europeans, Chinese and Japanese for simple addition, subtraction, multiplication and division, it is made up of wooden frame divided into two parts by a beam. On its upper part is a deck of two rows of beads. A series of vertical rods allow the beads to slide. Napier’s Bone (1617)  Napier’sBone Napier’s Bone (1614 - 17) John Napier world’s first practical calculator could multiply, divide and find roots of numbers developed in England carved on ivory sticks (logarithms) Napier’s Bone  Named after its inventor, Scottish Mathematician John Napier, this tool is made up of multiplication tables inscribed in a wood or bone. Slide Rule ( 1620) Slide Rule - 1632 William Oughtred based on Napier’s rules for logarithms used in 1960s by the Apollo programs which landed men on the moon also known as slip stick Slide Rule Invented by William Oughtred, this is a single straight two foot long ruler plotted with a logarithmic scale. Multiplication and division are done by using a pair of dividers. Manual Mechanical Calculators Pascaline calculator Pascaline Pascaline - 1642 Blaise Pascal used gears/toothed wheels an aid for his father who was a tax collector 50 Pascaline were built still used in car’s speedometer, watches, electric meter Pascaline calculator Thismachine was the first operational calculating machine that could add large numbers. It was invented by Blaise Pascal, a French mathematician. Step Reckoner (1670) Stepped Step Reckoner Reckoner - 1671/1673 Step Reckoner Gottfried von Leibnitz , a german baron, improved the Pascaline into a device that could add, subtract, multiply, divide and get square roots. Difference Engine (1822) Difference Engine - 1822 Charles Babbage (Father of Modern Computer) a general-purpose machine capable of performing different functions based on programming. a government funded project Difference Engine  Charles Babbage was a British Mathematician and inventor who built a machine that automatically calculated mathematical tables, such as logarithmic and trigonometric tables. He called this machine a “computer”. Analytical Engine (1830) Analytical Engine - 1832 Charles Babbage a programmable calculator, very close to the basic idea of a computer could do an addition in 3 sec and multiplication & division in 2-4 mins. Analytical engine  This was also invented by Charles Babbage. Compared to the difference engine, the analytical engine was not only able to perform calculations but also to store data in the memory and perform logical comparison. Electro Mechanical Computers Hollerith’s Tabulating Machine (1890) Tabulating Machine Tabulating Machine - 1890 Herman Hollerith used effectively in the US census (completed in 3 years & save 5 million dollars) used cards which are read electronically Tabulating Machine Company → IBM Hollerith’s Tabulating Machine (1890) Invented by the American inventor Herman Hollerith, this machine was capable of representing, reading and assembling data. Electronic Computers MARK 1  Invented by Dr. Howard Aiken, it is the first operating machine that could perform long computations automatically. It could execute addition and subtraction in a second, multiplication in six seconds, division in 15.3 seconds and logarithm and trigonometric functions in over one minute. Mark I Mark I - 1943 ASCC Howard H. Aiken Automatic Sequence-Controlled Calculator an electro-mechanical computer weighed 5 tons, incorporated 500 miles of wire, 8 feet tall and 51 feet long , had 50 ft rotating shaft, turned by a 5 hp electric motor ENIAC or Electronic Numerical Integrator and Computer (1946) ENIAC – 1943-45 ENIAC (1946)  Developed by John Mauchly and J Presper Eckert, it was the first general purpose electronic computer which was made up of vacuum tubes. It was used to process one problem at a time. UNIVAC 1 or Universal Automatic Computer (1951) UNIVAC UNIVAC - 1950 UNIVAC 1  Itis the first commercially available computer that could perform about 1,905 operations per second running on a 2.25 megahertz clock. The complete system occupied more than 35.5 m² of floor space. Modern Electronic Computers GENERATIONS OF COMPUTERS FIRST GENERATION COMPUTERS  These computers were bulky, took up large space, and needed to be kept in a cool environment. They used wired circuits that had thousands of vacuum tubes, each of which was about the size of a light bulb. SECOND-GENERATION COMPUTERS  Unlike the first-generation computers, which used vacuum tubes, these computers used transistors which were smaller, more efficient, and less energy consuming. THIRD-GENERATION COMPUTERS  Calledminicomputers, these computers were compact, reliable, and less expensive. Instead of transistors, they use integrated circuits (ICs) or chips which are much smaller compared to transistors.