The wheel turns full circle...

In 1958 a young Japanese researcher, Eiiti Wada, worked on the design of a new computer, one of the first to be built in Japan. Wada made a detailed study of the Edsac, and derived many of his programing ideas from it. I met Eiiti at a conference a couple of years ago, and he took away with him a copy of the Edsac simulator. A few days ago he e-mailed me as follows:

I really enjoyed the simulator. 40 more years ago, I studied the Edsac programs very hard. But I never wrote one, only reading.

However, since I now have the Edsac, I wanted to write one program myself. On page 38, you wrote about the sieve of Eratosthenes programmed by Wheeler. Half century later, I tried the same program. Here it is.

The program is beautifully written and very fast. A little master work.

Martin Campbell-Kelly
5 April 2001