All of us here love computers don’t we? Yes, of course we do why else would we blog? Thank goodness for these modern marvels that let us read news from all over the world, watch videos, share images, chat to our friends, etc. Computers are without doubt the most wonderful invention of the modern age.

But are computers really modern? Electronically the answer may be ‘yes’ since the first real computer wasn’t built until 1948. 1948? I thought computers were used for cracking Nazi codes during the Second World War?

There is no doubt that Alan Turing was the first to describe the architecture of the general purpose computer, by way of his 1937 paper on 'Computable Numbers' which proved the existence of an abstract general purpose computer (now known as the Universal Turing Machine). When considering whether or not some kind of device or formal system has the power of the general purpose computer, mathematicians and computer scientists now use the term Turing-equivalent as shorthand for this capability.

In 1943 Tommy Flowers (working with Turing at Bletchley Park) built the first Colossus machine, a programmable computer specially designed to crack the German Enigma military cipher machines. It was built in the novel electronic valve technology which had been brought to the Bletchley code-breaking effort by Flowers from the GPO. Too specialised really to deserve the title of a 'general purpose computer', it nevertheless contained all the elements of the modern general purpose computer except the crucial stored program in strict literal terms, although it is arguable that its high speed tape loops were a recognition and implementation of the idea in random access backing store. British Government secrecy about code-breaking kept this and subsequent work very little known outside those directly connected with British computer design until recently. At the end of the war the Bletchley Colossus machines were carefully smashed up into small pieces so they could never be used again or developed further. So anyway, in strict terms Colossus doesn’t count because it couldn't store a programme.

It’s generally accepted that the Small-Scale Experimental Machine, known as SSEM, or the 'Baby', which was designed and built at The University of Manchester and made its first successful run of a program on June 21st 1948 was the first practical general purpose computer. It was the first machine that had all the components now classically regarded as characteristic of the basic computer. Most importantly it was the first computer that could store not only data but any (short!) user program in electronic memory and process it at electronic speed.

From this Small-Scale Experimental Machine a full-sized machine was designed and built, the Manchester Mark 1, which by April 1949 was generally available for computation in scientific research in the University. With the integration of a high speed magnetic drum by the autumn (the ancestor of today's disc) this was the first machine with a fast electronic and magnetic two-level store. It in turn was the basis of the first commercially available computer, the Ferranti Mark 1, the first machine off the production line being delivered in February 1951.

Mechanical computers were in existence way before this though and we have to thank Charles Babbage and his Difference Engine, 1834, for inventing the principle of the analytical engine, the forerunner of the modern electronic computer.

Quite stunningly the Greeks developed an analogue computer some 2000 years before Babbage. The Antikythera Mechanism as it is known, discovered more than 100 years ago in a Roman shipwreck, was used by ancient Greeks to display astronomical cycles. The device worked by turning a small handle connected to an arrangement of hand-cut bronze gears and could have been used to predict solar and lunar eclipses. The elaborate arrangement of bronze gears may also have displayed planetary information.

So okay computers aren’t really new, but we love ‘em anyway! Ain’t technology wonderful?