A Leyden jar is simply a cylindrical container made of insulating material, like plastic or glass, with a layer of metal foil on the inside and outside. With the outside surface grounded, a charge is given to the inside. An equal charge is then built up on the outside, and when the two are connected - SNAP ! Like other physicists of his time, Muschenbroeck believed that electricity was a fluid, like water, and could therefore be contained in a jar. The two men went on to perform a bizarre public experiment using 100 monks in a circle, holding hands. When one monk got an electric shock, so did the other 99. He later went on to perform a bizarre public experiment, involving a large Leyden Jar and 1000 monks, all holding hands in a circle. When the first monk received a shock from the discharge, so did the other 999!
The First Capacitor - 1746 <ul><li>A student, Cuneus, at the University of Leiden in Holland, was given the task of “electrifying” some water in a jar. </li></ul><ul><li>He was shocked (!) to discover that electricity and water do not mix! </li></ul><ul><li>His Professor, Muschenbroeck, repeated Cuneus's experiment; and between them, they invented the Leyden Jar. </li></ul><ul><li>Nowadays we would call this a condenser or capacitor. </li></ul>
The First Externally Programmed Computer - 1835 <ul><li>Charles Babbage's design of 1822, for his "Difference Engine", is regarded by many as being the blueprint of the world's first true computer. </li></ul><ul><li>Despite the first Government-funded IT grant in history, Babbage was plagued by debt and family problems, and the computer was never built. </li></ul>The Difference Engine on display at the London Science Museum.
The First Externally Programmed Computer - 1835 <ul><li>Babbage redesigned his invention as the Analytical Engine, but the Government refused to put up any more money. </li></ul><ul><li>Babbage continued to redesign and refine his plans until his death. It was finally built in part by his son, Major Henry Babbage, in 1906. </li></ul><ul><li>The first program was to calculate and print the first 25 multiples of to 29 decimal places, to demonstrate that it worked. </li></ul>
The First Vacuum Valve - c1901 <ul><li>The first true valve was developed by John Ambrose Fleming, an English physicist, who was attempting to improve the reception of wireless radio signals. </li></ul><ul><li>It consisted of a glass bulb with two electrodes in it, and a metal filament (cathode) heated to the point where it fired electrons. </li></ul>This action caused a current to flow in one direction only - hence the name “valve”. Nowadays we would refer to this device as a diode . This effect had already been discovered by the American inventor Thomas Edison, but he had discarded the idea as worthless.
The First Vacuum Valve - c1901 <ul><li>Because of this, tubes frequently burned out and had to be replaced. </li></ul>The first American computer, the ENIAC, used 19,000 glass valves, filled several large rooms and consumed enough power to light ten homes. The vacuum tube's cathode required phenomenal amounts of power in order to boil out electrons - almost all the electricity in a tube is converted to heat.
The First Triode - 1906 In 1906 the American inventor, Lee DeForest, added an extra component to Fleming's vacuum tube. It was a third electrode, called a grid, a network of small wires surrounding the cathode. DeForest found that he could both control and amplify the current flow - he had invented the “Audion” valve, or triode . High power transmitters still use valves, and cathode ray tubes are still used in their millions. By the 1960’s, however, valves were largely being replaced by solid-state technology.
The First Freely Programmable Computer (Mechanical) - 1936-8 <ul><li>The first freely programmable computer was built between 1936 and 1938, financed completely from private funds. </li></ul><ul><li>The inventor, Konrad Zuse, had already approached the government to try and obtain backing for his invention, but the government of the day - Hitler's National Socialists - could see no value in it, and sent Herr Zuse on his way. </li></ul>The rebuilt Z2, on display at the Deutsche Techniksmuseum in Berlin
The First Freely Programmable Computer (Mechanical) - 1936-8 <ul><li>Undeterred, Konrad began building his computer in the living room of his parents' flat. </li></ul>His original mechanical Z1 had a control unit, nano-processor, 64-bit memory and a floating point unit. It ran at 1 Hertz, used 22-bit registers and took approximately 5 seconds to multiply two numbers.
The First Freely Programmable Computer (Mechanical) - 1936-8 Unfortunately the Z1 was not very reliable, because it used 20,000 hand-sawn metal plates, which were bulky, complex and fragile. All the work and plans were destroyed in the Allied bombing of Berlin in 1943. Herr Zuse finally obtained a Government grant to reconstruct the computer. It was completed in 1989, shortly before his death.
The First Freely Programmable Computer (Electrical) - 1946 (American Version) . The US Dept. of Defense’s Electrical Numerical Integrator and Computer (ENIAC) was developed during WW2 to calculate trajectories for artillery. ENIAC weighed in at just over 30 tons with almost 19000 valves, 1500 mechanical relays and hundreds of thousands of resistors, capacitors and inductors.
The First Freely Programmable Computer (Electrical) - 1946 (American Version) . Unfortunately ENIAC was not was completed until the end of the war. But by then the Army had thought of many more possibilities for it. ENIAC went online at the Moore School of Electrical Engineering at the University of Pennsylvania on February 15, 1946. The most famous and classic shot of ENIAC at the Moore School.
The First Freely Programmable Computer (Electrical) - 1946 (American Version) As well as military applications, ENIAC went on to do weather predictions, atomic energy calculations, cosmic ray studies, thermal ignition, random number studies and wind tunnel design. ENIAC was finally decommissioned on October 2, 1955. Part of it is now on display at the Smithsonian Institute.
The First Freely Programmable Computer (Electrical) - 1943 (Correct Version) . At the start of WW2, Hitler’s forces were using a device, first patented in 1919, which could encrypt and encode telegraphed messages. This device was called Enigma . It looked and behaved much like a mechanical typewriter, but with a couple of major differences….
The First Freely Programmable Computer (Electrical) - 1943 (Correct Version) Each typed letter was encrypted by using wheels and circuits. When a key was pressed, an entirely different letter would appear on a lighted keyboard above. This device enabled Hitlers’ forces to send important information in complete secrecy. Finally in 1941 the Polish Resistance managed to capture the blueprints.
The First Freely Programmable Computer (Electrical) - 1943 (Correct Version) The British Ministry of War already had a team of codebreakers working at Bletchley Park, now part of Milton Keynes. But the high-quality codes could take up to 5 months to decrypt. One of the mathematicians in the team, Dr Alan Turing, and talented Post Office engineer Tommy Flowers, began to build an electronic calculating device to speed up the process.
The First Freely Programmable Computer (Electrical) - 1943 (Correct Version) . The result was the worlds’ first electronic computer - Colossus. 10 Colossi in all were built, reducing the decoding time to a matter of hours.
The First Freely Programmable Computer (Electrical) - 1943 (Correct Version) . At the end of the war, the codebreakers were sworn to secrecy, the computers were dismantled and all the technical drawings and diagrams were burned. Their existence was to remain a secret for nearly 30 years.
The First Transistor - 1947 <ul><li>In December of 1947 three research scientists at Bell Labs invented a solid state device that they called a transistor. </li></ul><ul><li>This was based on a piece of germanium crystal, with a pointed "cat's whisker" touching its surface. </li></ul>
The First Transistor - 1947 <ul><li>In 1956 the three men, Shockley, Bardeen and Brattain were awarded the Nobel Prize for Physics. </li></ul><ul><li>In the same year, the Western Electric Company began to supply all sorts of electrical manufacturers with the new solid state devices. </li></ul>Within the next 25 years, valve technology would be virtually dead. Alan Shockley explains how his transistor works.
The First Transistor - 1947 <ul><li>The first transistor was about </li></ul><ul><li>1 ½ cm high. Today, a processor such as a Pentium can contain up to 27 million of them…. </li></ul><ul><li>The latest transistors are fashioned from a single molecule of carbon-60 between two gold electrodes. </li></ul>These “Buckyballs” are so tiny that, as transistors, they only permit one electron at a time to move through them. This opens the door to the study of single-electron transport effects.
The First Video Game - 1972 <ul><li>The first true Video Game was invented in 1971 by the two-man team of Nolan Bushell and Al Acorn. </li></ul><ul><li>Nolan’s contract was with Atari, a fledgling games company who actively promoted themselves as a much bigger organisation than they really were. </li></ul><ul><li>In 1977 Warner Brothers bought out Nolan Bushnell for $30m - a large amount of money even today. </li></ul>
How Chips Are Made <ul><li>Microchips are made from silicon, one of the most prolific materials on Earth. Unlike the sand on the beach, however, it must be 99.9999% pure! </li></ul><ul><li>First, the silicon is compressed into a cylinder and baked at 1000 ºC. Then other elements such as boron, arsenic and phosphorous are added. </li></ul>Chips must be produced in sterile conditions as even a microscopic speck of dust would ruin them.
How Chips Are Made <ul><li>The rod is then sliced into thin strips with a diamond saw. The circuit pattern is laid on the surface and the background etched away with acids. This process will be repeated many times until the circuit is complete. </li></ul>This 10cm slice contains 500 chips, each of which contains about 50,000 transistors.
How Chips Are Made <ul><li>The lucky ones are then mounted in a ceramic or plastic “package” with microscopically fine soldered gold wires. The whole thing is then soldered into a machine. </li></ul>The chips are then tested - even if only 1 of the transistors is defective, the whole chip will be thrown away. Ferranti once estimated that only 1 in 20 of their chips actually made it!
Some More Amazing Chip Pictures A chip next to some grains of salt... … and a human hair.