This happened on 21 June 1948, and the world's first working program on an electronic stored-program computer, to find the highest factor of an integer by crude brute force trial, had been written by Kilburn.
Nothing was ever the same again. We knew that only time and effort were needed to make a machine of meaningful size.
We doubled our effort immediately by taking on a second technician.
It was in these circumstances that Kilburn mentioned to Tootill a few days later that 'there's a chap called Turing coming here, he's written a program.'
Williams knew about Alan because of his dealings with the NPL. Kilburn vaguely knew of him.
Tootill, who had not heard of him at all, worked on the program.
He was astonished (and naturally, smugly pleased) to discover it not only to be inefficient but to contain an error.
At Manchester they had a machine which actually worked, and this simple fact counted for more than did ingenious or impressive plans.
It meant that while Alan had been away on his holidays, political considerations had transformed the Manchester set-up.