He wrote off to F.C. Williams for information, and received a reply probably on 8 July.
By this time, the fact was that they had already, on 21 June 1948, successfully run the first program on the first working stored program electronic digital computer in the world.
It used, for storage, the cathode ray tube that Williams had developed, and at this point the total store consisted of just 1024 binary digits stored on one tube.
Alan drew attention to this figure in a table of 'memory capacities' in this report:
ENIAC without cards and with fixed programme 600
ENIAC with cards ∞
ACE as proposed 60,000
Manchester machine as actually working (8/7/48) 1,100
It was a pointed contrast between one machine still merely 'proposed', and another that actually worked.
But the figures also pointed to the fact that F.C. Williams had pursued his project in a more modest way.
The Manchester computer was small, and might even be called small-minded.
But it was the first embodiment of a Universal Turing Machine, albeit with a very short 'tape'.
Alan wrote out a little routine to perform long division, and posted it north immediately.