THE HISTORY OF CALCULATION LEADING TO TO-DAY’S COMPUTERS by E.C. WRIGHT, member.

At the Durrinqton Community Centre – 14th December, 1988,

I. To-day there are four main types of computer.

1. Word processor.

2. Micro computer – similar to Word processor.

3. Mini computer – used by an average size business, with 2 operators for such straightforward jobs as wages, stores etc. Now going out of use.

4. Main Frame – Very large with remote terminals.

We rapidly trace developments to these from the first known calculating device, the ABACUS from some centuries B.C. It is still used in a number of countries, e.g. China.

II. Numeric Systems.

The Roman numerals do not lend themselves to easy calculation! They also had no zero. The Arabic numerals were introduced into Europe by A1 Khwarism, an Arab, about 1200 A.D., and with its denary (decimal) system was proved to be much more suitable in the development of calculations. Much later the Binary System was found to be more adaptable for calculations by machine.

Ill Calculating Machines

In the 17th century the Astronomer John Napier needed to develop methods of calculation for his work. He introduced logarithms. He also produced a “machine” of “rods” or “bones”, appropriately marked cards, to calculate.

In 1621 William Oughtred invented the Slide rule, simply adding (or subtracting) lengths corresponding to the logarithms of numbers.

In 1642 an 18 year old, Blaise Pascal in France, invented an adding machine the “Pascaline”, to assist his father in his business as a tax collector. The machine was developed to a high degree and 50 were built but unfortunately Pascal could not sell them! The original is in the Conservatoire des Arts et Metiere, Paris.

Subsequently Leibnitz developed Pascal’s machine to multiply and divide. His first ideas proved impracticable because the mechanical precision needed to make the parts could not be achieved at that time. His second stage was to string together a number of statements, the basis of todays computer programming. Thirdly he adopted the Binary System instead of the Denary System of counting.

By 1821 Thomas de Colmar was able to construct the first precision machine successfully using a succession of geared wheels, and in 1855 Dorr Felt developed the Comptometer which was in use up to about 1940. In this the power needed to operate it was provided by pressing keys. William

Burrows introduced an Adding and Listing machine with a Tally Roll (1913).

A Cambridge University Mathematician Charles Babbage, sometimes referred to as the “The Father of the Computer”, wrote Mathematical table’s to facilitate calculation. At that time the Analytical Society was formed by him.

In 1882 a “Difference Engine” a geared calculator was introduced. This was developed with assistance from the Royal Society and funded by the Government. Again the difficulty of making parts to the required precision slowed down this more complex project, and, the Government withdrew its support (not for the last time – sic!). However Babbage left a model with many detailed drawings. This included the concept of punched cards.

IV Some other events.

Joseph Jaquer – a textile manufacturer in France – used punched cards, to control weaving looms to produce different patterns (I’ve seen one in use in N. Wales recently! S.J.M.)

In 1847 Boole devised his system of algebra, valuable in describing and manipulating logical expressions, an important advance.

Kelvin developed the first Analogue computer to predict tides (1872); From about 1900 developments in electronics took place that would have major influence on the design of computers, such as the thermionic valve and magnetic tape and drums (developed by Poulson circa 1900).

V The American Census’s of 1890, 1900, and 1910 increasingly

used a punched card/mechanical calculator system developed by Dr. Hermann Hollerith (1860-1929). The system could (a) be programmed (b) have a memory (c) use an arithmetic unit and (d) read a stack of punched cards.

The 1890 census took 7 years to complete manually for 50 million people, while the 1900 took 3 years for 63 million using Hollerith.

From the turn of the century large numbers of very successful electrically driven machines with nears and levers were produced. This gave manufacturers valuable experience to develop electronic machines in the mid century.

VI Modern Computers.

1st Generation up to 1954. These were at first mostly, slow, ponderous macnines.

Alan Turing (NPl 1937) showed that only a small set of instructions was needed to solve complex problems. And in 1938 Shannon showed

electrical switching could perform logical operations using Boolean algebra.

Konrad Zuse (German) built simple computers with binary numbering, leading to wartime computers for guiding aircraft and the VI and V2 bombs – destroyed by Allied bombers. Also during the war British developed Colussus (it has 1500 valves!) to break the German Enigma

code.

After the War in the U.S.A. (1946) EnIAC using 18,000 valves was built in 3 years! Requiring 15,000 sq. ft. floor space and weighing 30 tons it was programmed for any specific job by re-wiring which took a week!! After many early difficulties with ENIAC, Von Neumann suggested that a programme could be stored in a memory system with coded instructions. His principles are the basis of all subsequent computers.

The Manchester University Mark I (1948) used Neumanns principles. This had keyboard input, V.D.U., small binary memory, program store and a speed of 1-2 millisecond per instruction.

The first really commercial machine was EDVAC, for the U.S. army, developed from ENIAC.

N.P.L. built ACE in 1951 – one of the first fast machines.

LEO (1951) built by E.E.Co. with J. Lyons Co. was the first commercial machine in the U.K.

VII Second Generation (1954-1964)

(1948) The transistor, invented by William Shockley eliminated thermionic valve problems.

TXO (Transistor Experimental Computer) (1955) built by Massachusetts Inst, of Technology in under 4 years led to all new computers using this technique – e.g. IBM series 7000 and LEO Mark 3. This reduced their size, cost and power consumption, and made for simplicity, improved memory facilities and reliability.

VIII Third Generation (1954-72)

The first integrated circuit (1956) of one transistor and one resistor on a small germanium chip opened the way for this stage. Later chips were of silicon..

IX Fourth Generation (1972 – present).

The micro-processor revolution leading to L.S.I. (Large Scale Integration) on “chips” – which each have thousands of components.

X Fifth Generation, may be from 1990 by the Japanese!

We may assume now that the transputers will take over.