雙語暢銷書《艾倫圖靈傳》第9章:退隱山林(57)
In 1876 the French mathematician E. Lucas proved that there was a way to decide whether 2p—1 was prime by a process of p operations of squaring and taking of remainders.
He announced that 2127—1 was prime. In 1937, the American D.H. Lehmer attacked 2257—1 on a desk cAlculator and after a couple of years of work showed that Mersenne had been mistaken.
並證明了2127-1是素數。1937年，美國的D·H·萊默利用臺式計算器證明了2257-1是素數。接下來幾年的工作表明，梅森的猜想是錯誤的，In 1949 Lucas's number was still the largest known prime.
直到1949年，盧卡斯的素數依然是人們所知的最大素數。
Lucas's method was tailor-made for a computer using binary numbers.
盧卡斯的方法是專門爲二進制計算機設計的，They had only to chop up the huge numbers being squared into 40-digit sections and to program all the carrying.
所以他們需要做的工作，只是把大數分割成40位的小塊，以便於存儲。Newman explained the problem to Tootill and Kilburn and in June 1949 they managed to pack a program into the four cathode ray tubes and still leave enough space for working up to P = 353.
紐曼給托蒂爾和吉爾博解釋了這個問題，並且在1949年6月，他們成功地做到，在加載了程序之後，仍有足夠的空間來處理p小於353時的所有情形。En route they checked all that Euler and Lucas and Lehmer had done, but did not discover any more primes.
他們檢查了歐拉、盧卡斯和萊默的所有工作，但卻沒能找到更大的素數注。This was part of an uneasy treaty of alliance, according to which the zones of 'engineers' and 'mathematicians' were agreed.
這不是一個簡單的合作，是"工程師"和"數學家"之間的妥協。Newman took little further interest in the machine, and Alan took on the role of 'the mathematician'.
紐曼對這臺機器已經不怎麼感興趣了，圖靈接替了"數學家"的角色。It was for him to specify the range of operations that should be performed by the machine, although his list was in fact cut back by the engineers.
現在可以由他來指定，用什麼操作來展示這臺機器，儘管他提出的列表，已經被工程師們刪減了不少。He had no part in the internal logical design, which was done by Geoff Tootill, but had control over the input and output mechanism, which lay more in the province of the user.
圖靈在內部邏輯設計方面沒有任何話語權，這些都由托蒂爾負責，他負責的是輸入和輸出機制，這與機器的使用者更直接相關。At the NPL he had chosen punched cards for input since they already had a punched card section; here he preferred to generate a teleprinter tape which could later be run off on a printer.
在國家物理實驗室，因爲他們有一個打孔卡片部門，所以圖靈就選擇用打孔卡片進行輸入。而在這裏，他則更喜歡產生一條電傳紙帶，這樣就可以把它放進電傳打字機。
