Showing posts with label History of computers. Show all posts

John von Neumann

1.He was a mathematician who discovered stored program technology in 1945AD.

2.He was regarded as "father of stored program"

3.Stored-program concept, Storage of instructions in computer memory to enable it to perform a variety of tasks in sequence or intermittently.

4.His technique made computer faster, more flexible and more efficient. The idea was introduced in the late 1940s by John von Neumann, who proposed that a program be electronically stored in binary-number format in a memory device so that instructions could be modified by the computer as determined by intermediate computational results.

5.The key element to the von Neumann architecture was the central processing unit. Other engineers, notably John W. Mauchly and J. Presper Eckert, contributed to this idea, which enabled digital computers to become much more flexible and powerful. Nevertheless, engineers in England built the first stored-program computer, the Manchester Mark I, shortly before the Americans built EDVAC, both operational in 1949.

Digi-comp-I and II

The Digi-Comp I was a functioning, mechanical digital computer sold in kit form. It was originally manufactured from polystyrene parts by E.S.R., Inc. starting in 1963 and sold as an educational toy for US$4.99.

A successor, the Digi-Comp II, was not programmable, but in effect a visible calculator. A two-level masonite platform with guides served as the medium for a supply of marbles that rolled down an inclined plane, moving plastic cams as they fell.

Design and purpose:-

In essence, the Digi-Comp I contained three mechanical flip-flops, providing an ability to connect them together in a programmable way using thin vertical wires that are either pushed, or blocked from moving, by a number of cylindrical pegs. The whole arrangement was 'clocked' by moving a lever back and forth. Different configurations of these cylinders caused the Digi-Comp to compute different boolean logic operations. With a three binary digit (3-bit) readout of the state of the flip-flops, it could be programmed to demonstrate binary logic, to perform various operations such as addition and subtraction, and to play some simple logic games such as Nim.

source:wikipedia.org

Globus IMP instruments

Introduction:-

Globus IMP instruments were spacecraft navigation instruments used in Soviet and Russian crewed spacecraft. The IMP acronym stems from the Russian expression Indicator of position in flight, but the instrument is informally referred to as the Globus. It displays the nadir of the spacecraft on a rotating terrestrial globe. It functions as an onboard, autonomous indicator of the spacecraft's location relative to Earth coordinates. An electro-mechanical device in the tradition of complex post-World War II clocks such as master clocks, the Globus IMP instrument incorporates hundreds of mechanical components common to horology. This instrument is a mechanical computer for navigation akin to the Norden bombsight. It mechanically computes complex functions and displays its output through mechanical displacements of the globe and other indicator components. It also modulates electric signals from other instruments.

Design and purpose:-

The Voskhod spacecraft was the second generation of spacecraft designed in the crewed Soviet space program, essentially an adaptation of the earlier Vostok spacecraft. It flew two crewed missions, Voskhod 1 (world's first multi-crewed mission, launched on 12 October 1964) and Voskhod 2 (featuring the world's first Extra-vehicular activity, or EVA, commonly called a spacewalk, launched on March 18, 1965). The Voskhod spacecraft—and its Globus IMP instruments—is a close derivative of Vostok, which flew six Soviet individuals to low Earth orbit, including the world's first human in space, Yuri Gagarin, and the world's first woman in space, Valentina Tereshkova. The main difference between IMP versions 1 and 2 (Vostok spacecraft) and later versions (Voskhod and Soyuz) is the addition of the disc-shaped longitude and latitude indicators.

The design objectives for the IMP were to compute and display the geographic coordinates at the spacecraft's nadir, i.e. which point on Earth's surface it was overflying. The Globus displayed this data to the crew, and also transmitted electrical data to other systems through a variable resistance and cam-activated switching.

Derivatives of Vostok's and Voskhod's IMP have been flown on every Soyuz spacecraft up to the last of the Soyuz TM mission in April 2002. The main functional addition to IMP versions designed for Soyuz was the ability to manually change the orbit inclination. On Vostok and Voskhod, the inclination to the equator had been constant at 65 degrees by virtue of the booster design limitations and the geographical location of the Baikonur Cosmodrome from which every Soviet and Russian crewed mission had been launched to date, so there was no need to implement inclination modulation into versions 1 to 4 of the IMP.

The Soyuz TMA spacecraft and its successors now provide similar functions to the Globus using a computerized world map on a computer display.

The Russian early missions were mostly automated and controlled from the mission control center (the TsUP). The spacecraft essentially controlled itself, and the cosmonauts were expected to initiate maneuvers or corrections only after approval from the MCC and according to its data and parameters. Therefore, the instrumentation available to the pilot was minimal and its operational relevance was limited to contingency scenarios as much as possible. The readings from the IMP were primarily intended to help cosmonaut pilots confirm that the automated flight sequencer was operating normally. The data would also keep the crew aware of their position when they were orbiting over the nighttime part of the Earth, or when the spacecraft's viewports and Vzor periscope couldn't be pointed toward the ground.

However, the IMP would become crucial if manual retrorocket activation became compromised by failure of either the flight sequencer or communications with mission control, as did happen on Voskhod 2. Furthermore, given the scarcity of Soviet communication stations on Earth, the cosmonauts spent most of their time out of range with ground control and needed instruments to assess their position relative to the ground.

By contrast, the US crewed space programs used a similar, mechanical positional indicator only during two of its early Mercury missions before discarding it (and using its former niche in Mercury's instrument panel as an equivalent to a car's glove compartment). The American instrument was a crude, smaller equivalent to the Soviets', an all-mechanical device (hand-wound) of limited complexity. Given the more extensive radio communication network with the spacecraft afforded by NASA, all subsequent crewed missions, including lunar Apollo missions and Space Shuttle missions, used onboard maps, ground telemetry and more recently, computerized maps on portable laptop computers to provide the astronauts with positional information.

source:-wikipedia.org

Moniac computer

Introduction:-

The MONIAC (Monetary National Income Analogue Computer) also known as the Phillips Hydraulic Computer and the Financephalograph, was created in 1949 by the New Zealand economist Bill Phillips (William Phillips) to model the national economic processes of the United Kingdom, while Phillips was a student at the London School of Economics (LSE). The MONIAC was an analogue computer which used fluidic logic to model the workings of an economy. The MONIAC name may have been suggested by an association of money and ENIAC, an early electronic digital computer.

Design and uses:-

The MONIAC was approximately 2 m high, 1.2 m wide and almost 1 m deep, and consisted of a series of transparent plastic tanks and pipes which were fastened to a wooden board. Each tank represented some aspect of the UK national economy and the flow of money around the economy was illustrated by coloured water. At the top of the board was a large tank called the treasury. Water (representing money) flowed from the treasury to other tanks representing the various ways in which a country could spend its money. For example, there were tanks for health and education. To increase spending on health care a tap could be opened to drain water from the treasury to the tank which represented health spending. Water then ran further down the model to other tanks, representing other interactions in the economy. Water could be pumped back to the treasury from some of the tanks to represent taxation. Changes in tax rates were modeled by increasing or decreasing pumping speeds.

Savings reduce the funds available to consumers and investment income increases those funds. The MONIAC showed it by draining water (savings) from the expenditure stream and by injecting water (investment income) into that stream. When the savings flow exceeds the investment flow, the level of water in the savings and investment tank (the surplus-balances tank) would rise to reflect the accumulated balance. When the investment flow exceeds the savings flow for any length of time, the surplus-balances tank would run dry. Import and export were represented by water draining from the model and by additional water being poured into the model.

The actual flow of the water was automatically controlled through a series of floats, counterweights, electrodes, and cords. When the level of water reached a certain level in a tank, pumps and drains would be activated. To their surprise, Phillips and his associate Walter Newlyn found that MONIAC could be calibrated to an accuracy of 2%.

The flow of water between the tanks was determined by economic principles and the settings for various parameters. Different economic parameters, such as tax rates and investment rates, could be entered by setting the valves which controlled the flow of water about the computer. Users could experiment with different settings and note the effect on the model. The MONIAC’s ability to model the subtle interaction of a number of variables made it a powerful tool for its time. When a set of parameters resulted in a viable economy the model would stabilise and the results could be read from scales. The output from the computer could also be sent to a rudimentary plotter.

MONIAC had been designed to be used as a teaching aid but was discovered also to be an effective economic simulator. At the time that MONIAC was created, electronic digital computers that could run complex economic simulations were unavailable. In 1949, the few computers in existence were restricted to government and military use. Neither did they have adequate visual display facilities, so were unable to illustrate the operation of complex models. Observing the MONIAC in operation made it much easier for students to understand the interrelated processes of a national economy. The range of organisations that acquired a MONIAC showed that it was used in both capacities.

Phillips scrounged a variety of materials to create his prototype computer, including bits and pieces from war surplus such as parts from old Lancaster bombers. The first MONIAC was created in his landlady’s garage in Croydon at a cost of £400 (equivalent to £14,000 in 2019).

Phillips first demonstrated the MONIAC to a number of leading economists at the LSE in 1949. It was very well received and Phillips was soon offered a teaching position at the LSE.

source:wikipedia.org

Curta

The Curta is a small mechanical calculator developed by Curt Herzstark. The Curta's design is a descendant of Gottfried Leibniz's Stepped Reckoner and Charles Thomas's Arithmometer, accumulating values on cogs, which are added or complemented by a stepped drum mechanism. It has an extremely compact design: a small cylinder that fits in the palm of the hand.

Curtas were considered the best portable calculators available until they were displaced by electronic calculators in the 1970s.

Design

Numbers are entered using slides (one slide per digit) on the side of the device. The revolution counter and result counter reside around the shiftable carriage, at the top of the machine. A single turn of the crank adds the input number to the result counter, at any carriage position, and increments the corresponding digit of the revolution counter. Pulling the crank upwards slightly before turning performs a subtraction instead of an addition. Multiplication, division, and other functions require a series of crank and carriage-shifting operations.

The Curta was affectionately known as the "pepper grinder" or "peppermill" due to its shape and means of operation. It was also termed the "math grenade" due to its superficial resemblance to a certain type of hand grenade.

source:wikipedia.org

Z1 computer

The Z1 was a motor-driven mechanical computer designed by Konrad Zuse from 1936 to 1937, which he built in his parents' home from 1936 to 1938. It was a binary electrically driven mechanical calculator with limited programmability, reading instructions from punched celluloid film.

The “Z1” was the first freely programmable computer in the world which used Boolean logic and binary floating-point numbers, however it was unreliable in operation. It was completed in 1938 and financed completely from private funds. This computer was destroyed in the bombardment of Berlin in December 1943, during World War II, together with all construction plans.

The Z1 was the first in a series of computers that Zuse designed. Its original name was "V1" for VersuchsModell 1 (meaning Experimental Model 1). After WW2, it was renamed "Z1" to differentiate from the flying bombs designed by Robert Lusser. The Z2 and Z3 were follow-ups based on many of the same ideas as the Z1.

Construction:-

"Z1 was a machine of about 1000 kg weight, which consisted of some 20,000 parts. It was a programmable computer, based on binary floating-point numbers and a binary switching system. It consisted completely of thin metal sheets, which Zuse and his friends produced using a jigsaw." "The [data] input device was a keyboard...The Z1’s programs (Zuse called them Rechenpläne, computing plans) were stored on punch tapes by means of an 8-bit code"

Construction of the Z1 was privately financed. Zuse got money from his parents, his sister Lieselotte, some students of the fraternity AV Motiv (cf. Helmut Schreyer) and Kurt Pannke (a calculating machine manufacturer in Berlin) to do so.

Zuse constructed the Z1 in his parent's apartment; in fact, he was allowed to use the living room for his construction. In 1936, Zuse quit his job in airplane construction in order to build the Z1.

Zuse is said to have used "thin metal strips" and perhaps "metal cylinders" or glass plates to construct Z1. There were probably no commercial relays in it (though the Z3 is said to have used a few telephone relays). The only electrical unit was an electric motor to give the clock frequency of 1 Hz (cycle per second) to the machine.

'The memory was constructed from thin strips of slotted metal and small pins, and proved faster, smaller, and more reliable, than relays. The Z2 used the mechanical memory of the Z1, but used relay-based arithmetic. The Z3 was experimentally built entirely of relays. The Z4 was the first attempt at a commercial computer, reverting to the faster and more economical mechanical slotted metal strip memory, with relay processing, of the Z2, but the war interrupted the Z4 development.'

The Z1 was never very reliable in operation because of poor synchronization caused by internal and external stresses on the mechanical parts.

source:wikipedia.org

Kerrison Predictor

The Kerrison Predictor was one of the first fully automated anti-aircraft fire-control systems. The predictor could aim a gun at an aircraft based on simple inputs like the observed speed and the angle to the target. Such devices had been used on ships for gunnery control for some time, and versions such as the Vickers Predictor were available for larger anti-aircraft guns intended to be used against high-altitude bombers, but the Kerrison's electromechanical analog computer was the first to be fast enough to be used in the demanding high-speed low-altitude role, which involved very short engagement times and high angular rates.

The Kerrison Predictor was a relatively simple device compared to high-altitude predictors and was designed to meet these particular requirements. It was designed by Major A.V. Kerrison at the Admiralty Research Laboratory, Teddington, in the late 1930s. After the war, Kerrison went on to become Director of Aeronautical and Engineering Research at the British Admiralty.

The Predictor solved the problem by doing all of the calculations mechanically through a complex system of gears. Inputs to its calculations included wind speed, ballistics of the gun and the rounds it fired, angle to the target in azimuth and altitude, and a user-input estimated target speed. Some of these inputs were fed in by dials, which turned gearing inside the Predictor to calculate the range (from the change in angle and estimated speed) and direction of motion. The "output" of the device drove hydraulic servo-motors attached to the traversal and elevation gears of the otherwise unmodified Bofors gun, allowing it to follow the predictor's indications automatically without manual intervention. The gunners simply kept the gun loaded, while the three aimers simply had to point the Predictor, mounted on a large tripod, at the target. The Kerrison predictor did not calculate fuse settings, as the shells fired by the 40 mm Bofors gun, with which it was designed to work, were contact-fused.

The Predictor proved to be able to hit practically anything that flew in a straight line, and it was particularly effective against dive bombers. However, it was also very complex, including over 1,000 precision parts and weighing over 500 lb (230 kg), even though much of it was made of aluminium to reduce weight. With the demands of the RAF for almost all light metals and machinists, the Predictor was far too difficult for the Army to produce in any quantity.

While the Predictor proved to be an excellent addition to the Bofors, it was not without its faults. The main problem was that the system required a fairly large electrical generator in order to drive the gun, increasing the logistics load in supplying the generators with fuel. Setting the system up was also a fairly complex task, and not something that could be done "on the fly". In the end they were used almost entirely for static emplacements, field units continuing to rely on their original iron sights or the simple Stiffkey-Stick sights that were introduced in late 1943.

The No.7 anti-aircraft composite predictor, also designed by Kerrison was similar in some ways. It was originally developed for the 6-pounder naval gun, for close-in defence and also against targets at intermediate altitudes of 6,000 to 14,000 ft (1,800 to 4,300 m). It was later adapted for use with the 40 mm Bofors.

History of computers

Evolution of Computer

The development of personal computers has taken a long period of time to extend the use of computers at present. There were not the advanced technologies in the ancient days. So it passed through several phases to become this phase in the present days.

The development of computers from ancient days to present days can be classified into the THREE Era which are as follows.

click the device to know in detail about that.

A) Mechanical Calculation Era

B) Electro- mechanical Era

C) Electronic Computers Era