A “Brief” History Abacus considered first mechanical computing device. Used beads and rods to count numbers. Developed around 3000 B.C.
Mechanical Calculator 1612 – John Napier used floating point arithmetic and invented the logarithm. 1622 – William Oughtred created the slide rule based on Napier’s logarithms. This was the primary calculator used by engineers until the 1960’s.
1642 – Blaise Pascal created a machine that could add and subtract, automatically carrying numbers. 1673 – Gottfried Leibnitz built a calculator that could multiply and divide as well.
1790 – Joseph Marie Jacquard invented an automatic loom using punched cards to control patterns in the fabrics. Punched cards were used to allowed some of the rods to pass through
Jacquards invention emphasized three important concepts: Storage: Coding of information by punching holes on the cards. Programming: Linking of the cards in series to provide instruction in sequence. Program Execution: Job would be performed automatically as the program run.
Charles Babbage 1786 – J.H Muller proposed a calculating machine called a Difference Engine. 1812 – Charles Babbage conceived idea of difference engine. He designed new machine called Analytical Engine.
Analytical Engine consisted of FIVE units. Store: Storing the data. Mill: Process the data. Control: Control the flow of data. Input: Enter the data. Output: Display the data.
Babbage’s Analytical Engine could not completed due to under development of technology. But laid foundation of digital computer. Also called FATHER of computer.
Electro-Mechanical Machines 1890 Hollerith won competition for developing data processing equipment for the US Census Bureau. Founded Hollerith Tabulating Company which became IBM in 1924.
Computer Generations Generation Technology Approx Dates First Vacuum Tube 1942-1959 Second Transistors 1959-1964 Third ICs 1964-1973 SSI/MSI Fourth Microprocessor 1973-1991 LSI/VLSI Fifth ULSI/AI 1991 onwards
First Generation 1942-1959 First Generation Electronic Computers used Vacuum Tubes. Invented in 1906. Vacuum tubes are glass tubes with circuits inside. Vacuum tubes have no air inside of them, which protects the circuitry.
1943 Work started on ENIAC at University of Pennsylvania under John Mauchly and J. Presper Eckert with Herman Goldstein. Used 18,000 vacuum tubes. U shaped, 25m long, 2.5m high, 1m wide, consumed 150 kw and weighed more than 30 tons.
Disadvantages: Very big in size Slow in speed (40,000 operation in seconds) Low reliability Large power consumption Difficult maintenance
Second Generation 1959-1964 Transistor was invented in 1948. Made up of from Silicon. A transistor is a semiconductor device used to amplify and switch electronic signals. Replaced vacuum tubes with Transistors.
Comparing with Transistors: Immediate functioning, no time for heating necessary. Smaller and low weight. Process up to 200,000 ois. Less power consumption. Low susceptibility to trouble and long lifetime
Third Generation 1964-1973 Third Generation Computers used Integrated Circuits (chips). Invented in 1947. Integrated Circuits are transistors, resistors, and capacitors integrated together into a single “chip”. Replaced Transistor with ICs
Comparing with Transistors: Very small in scale. Cheaper than transistors. More reliable. Process up to 1000,000 ois.
Fourth Generation 1973-1991 It contains micro chip. A small piece of semiconductor material carrying many integrated circuits (Transistors, resistors, and capacitors). Very Large Scale Integrated. 4004 had 2,250 transistors The first microprocessors emerged in the early 1970s and were used for electronic calculators, using binary-coded decimal (BCD) arithmetic on 4-bit words.
Fifth Generation 1991 onwards It contains all best combination. Getting smaller and smaller, but we are still using microchip technology. Ultra Large Scale Integrated circuits. Giving computer the ability to think. Artificial Intelligence and Expert systems.