Something I ran across in an old book on number theory In 1953 D.H.Lhmer used the SWAC calculator to check for Mersenne primes (2^n-1). The largest one found was n=2281 - the runtime was 66 minutes. Anybody with access to one of the new Cray fish-tanks want to get a datapoint for the closest machine in 96 so we can check on how well Moore's law worked? Simon // Suddenly my Powerbook 140 seems fast again