1.1 The arrival of the computer
The story of the invention of the digital computer is a fascinating one. Folklore has it that the computer originated in the United States, but this is not true. Britain, the USA and Germany developed the computer independently at almost exactly the same time. In terms of who got there first, it is Germany that carries off the cup â or more precisely a lone German, Konrad Zuse. He had the worldâs first general-purpose programmable computer up and running by the end of 1941.1 It was a case of third time lucky: two earlier machines that he built in the unlikely setting of his parentsâ living room did not quite work. Although Zuse was first past the post, few were aware of his achievement at the time, and Allied restrictions on electronic engineering in post-war Germany put paid to any further development. Neither Zuse nor his ideas played any significant role in the commercial development of the computer.2
The British story begins at Bletchley Park, Buckinghamshire, a top secret wartime establishment which was devoted to breaking the Wehrmachtâs codes. With a staff of brilliant mathematicians and engineers, it was almost inevitable that Bletchley Park should produce something revolutionary â and when it came it was the Colossus, an electronic3 computer for deciphering coded messages.4 The first Colossus was installed and working by December 1943, a full two years after Zuse obscurely made history in Berlin. (Some commentators quibble over whether the Colossus was a true computer.5 It was designed for just one specific task, cracking codes, and beyond that could do little or nothing. Enthusiasts at Bletchley had tried to coax the Colossus into doing long multiplication but, tantalizingly, this proved to be minutely beyond the frontier of the machineâs capabilities.6 Zuseâs computer, on the other hand, could be set up to perform any desired calculating task (provided, of course, the task was not so large as to exhaust the machineâs storage capacities). Zuseâs was a general-purpose computer, while the Colossus was a special-purpose computer.)
After the war the Bletchley group broke up and the action moved north to Manchester. It was here that F.C. Williams, Tom Kilburn and their team built the Manchester University Mark I general-purpose computer. The first program ran in June 1948.7 By April 1949 the small prototype had been expanded into a much larger machine.8 On the other side of the Atlantic progress ran just slightly slower. The first comparable American machine (called the BINAC) was tested in August 1949.9
A Manchester firm, Ferranti Limited, contracted to build a production version of the Manchester Mark I. These machines were the worldâs first commercially manufactured electronic stored-program computers. In all, nine were sold. The first was installed in February 1951, just two months before the appearance of the worldâs second commercially-available machine, the American UNIVAC.10
The Ferranti Mark I has the additional distinction of being the first non-human on the planet to write love letters.
Darling Sweetheart,
You are my avid fellow feeling.
My affection curiously clings
to your passionate wish. My
liking yearns to your heart. You
are my wistful sympathy: my
tender liking.
Yours beautifully,
Manchester University Computer11
The American side of the story begins with a machine known as the ENIAC. (The initials stand for Electronic Numerical Integrator and Computer. It is an exceptionless law that the acronyms used to name computers and computer programs never mean anything interesting.) The ENIAC was built at the University of Pennsylvania by John Mauchly and J. Presper Eckert, and first went into operation in November 1945 (nearly two years after the Colossus).
The ENIAC was a programmerâs nightmare â it had to be rewired by hand for each new task. This was a mammoth operation involving thousands of plugs and switches. It would generally take the operators two days to set the machine up for a fresh job.12 This primitive monkeying about with cables was all that the ENIAC had to offer by way of a programming facility. The Manchester Mark I was much less user-hostile. The Mark I was the worldâs first fully electronic stored-program computer.13 Setting it up to perform a new job involved simply feeding in a punched paper tape. The machine would copy the programmerâs instructions from the tape and store them in its own memory. Eckert and Mauchly had realised as early as 1943 that it would be beneficial to be able to store the ENIACâs operating instructions inside it, but the military wanted the ENIAC operational as soon as possible and so exploration of the stored-program concept had to wait.14
After the ENIAC, Eckert and Mauchly went on to build the BINAC, which was a stored-program machine. They then built the UNIVAC, the first market place offering of the nascent American computer industry. Thereafter the US quickly came to dominate the commercial production of computers. However, history has not been kind to Eckert and Mauchly. In 1972, a prolonged patents struggle between the Honeywell Corporation and Sperry-Univac ended with the judicial decision that âEckert and Mauchly did not themselves first invent the automatic electronic digital computer, but instead derived that subject matter from one Dr John Vincent Atanasoffâ.15 Atanasoff was an American college professor who very nearly succeeded in building a special-purpose electronic computer during the period 1936 to 1942.16 Unfortunately he never managed to get his machine properly operational, largely because of malfunctions in a cumbersome piece of equipment for storing information on punched cards. Mauchly paid a visit to Atanasoffâs laboratory in 1941, and in the opinion of the judge it was Atanasoffâs ground-breaking work that had led Mauchly and Eckert to the ENIAC. The judicial ruling notwithstanding, a dispute still rages over the extent to which Atanasoffâs ideas influenced Mauchly and Eckert.
This was not the first time that events had dealt Eckert and Mauchly a bitter blow. The months subsequent to the ENIAC becoming operational ought to have been their time of triumph, but in reality they found themselves upstaged by one of their colleagues â a certain John von Neumann. A gifted mathematician and logician, von Neumann has been described as an âunearthly geniusâ.17 Von Neumann heard of the ENIAC during a chance meeting on a railway station. He was working on the Manhattan Project at Los Alamos at the time, where he applied his great genius to such sinister problems as the calculation of the exact height at which an atomic bomb must explode in order to inflict maximum destruction. He was quick to see the implications of a machine like the ENIAC (âshell, bomb, and rocket work ⊠progress in the field of propellants and high explosives ⊠aerodynamic and shock wave problems âŠâ).18 He offered to act as consultant to the Eckert-Mauchly project, and rapidly established himself as national spokesman on the new computer technology. Von Neumann was a pillar of the scientific establishment and his patronage did wonders for the prestige of the ENIAC project, but as a result of his lectures and publications the computer came to be more closely associated with his own name than with the names of the people who had brought it into the world.19 Von Neumann had a saying that only a man born in Budapest can enter a revolving door behind you and come out in front.20 He himself, of course, was such a man, and it was Eckert and Mauchly who were left behind.
Von Neumann went on to make huge contributions to computer design. He enunciated the fundamental architectural principles to which subsequent generations of computers have adhered. For this reason, standard modern computers are known generically as von Neumann machines. We shall hear more of von Neumann in later chapters.
The name of John von Neumann is linked with the birth of artificial intelligence in another way. In 1956 the most influential of the early efforts at AI programming ran on the JOHNNIAC, a sophisticated computer designed by him.21 The program is known affectionately as the Logic Theorist. It was the work of Allen Newell, Cliff Shaw, and Herbert Simon, three of the great frontiersmen of AI.22