COPElAND & PRINz | 341
defeated him. It must have been a lonely time. He wrote sadly ‘Ich bin ein German refugee: there
is no Vaterland for me’, but at least he had a job. At Telefunken, before he fled Berlin, Prinz had
appealed for help to some visiting British engineers, from the electrical manufacturing company
GEC. As a result, a position awaited him at GEC’s Valve Development Laboratory in Wembley.
He had brought his patents with him from Germany, carefully packed in his suitcases:
these related to radio, television, and an exotic type of vacuum tube called the ‘magnetron’.^35
Nowadays, magnetrons produce the microwave energy for cooking food in microwave ovens,
but in pre-war Europe the magnetron was about to play a major role in radar. A group working
for the British Admiralty perfected the design in 1940, creating the ‘multi-cavity magnetron’;
this was said to have had more influence on the course of the war than any other single inven-
tion, since it was key to constructing small, powerful, and accurate radar sets, compact and
light enough to be fitted into aircraft.^36 Nazi anti-Semitism was costing German science dearly.
Prinz was welcomed into GEC and quickly grew to like his new life in England. ‘If someone
makes a mistake at work here’, he said, ‘they try to comfort him—instead of shouting at him’. It
didn’t last, though. In 1940, fearful of fifth columnists, Winston Churchill ordered the intern-
ment of enemy aliens. ‘Collar the lot’, he had said.^37 Prinz was arrested and taken to a police
station. Like thousands of his countrymen, he soon found himself on board a once-luxurious
passenger liner and heading for a prison camp in Canada. There were guns and barbed wire,
but little of the horrific barbarity of the camps in Germany. In fact, the inmates turned some
Canadian camps into impromptu universities, with captive scientists, engineers, and other
intellectuals teaching class.^38 Soon, however, the British authorities saw the folly of imprisoning
Nazi-hating refugees, and in 1941 Prinz again found himself crossing the Atlantic. This time his
destination was Cambridge and a job in the Pye electronics company, at a subsidiary special-
izing in cathode-ray tubes. Turing was also involved with Pye, in connection with the bombe.^39
By 1947 Prinz had adopted British nationality and was working for Ferranti, where he became
a first-generation code hacker, and eventually set up Ferranti’s programming department.^40
Like Turing and Strachey, he would work through the night at the computer. By the time Turing
arrived in Manchester, in the autumn of 1948, Prinz had been living for several months in a
leafy suburban street in Old Trafford (scarcely more than a stone’s throw from Old Trafford
stadium, home to Manchester United—although Prinz loathed football), and had been work-
ing on the idea of building specialized relay-based computers for performing complex logical
deductions.^41 It was Turing’s assistant at the National Physical Laboratory, Donald Davies, who
piqued Prinz’s interest in computer chess: Prinz was inspired by Davies’s important article ‘A
theory of chess and noughts and crosses’, which he read in a popular science magazine.^42 ‘ To
programme one of the electronic machines for the analysis of Chess would not be difficult’,
Davies wrote.^43 And so the adventure began.
Brute-force chess
Turing’s Turochamp was designed to play a complete game, but Prinz downsized the problem.
He decided to focus only on simple mate-in-two situations, having seen similar puzzles in the
competition pages of the New Statesman, and he tackled the job of writing a program to search
for mate-forcing moves. Even then he introduced further simplifications: no castling, no double
moves by pawns, no promotion of pawns, no captures en passant, and no distinction between
mate and stalemate.^44 With so much simplification there was no need for Turing’s heuristic