Bill Tutte's work led directly to the creation of the first programmable electronic digital computer so it was rather satisfying to spot a Pulsar P4 Time Computer on his wrist in an image on display at the "Bill Tutte: Mathematician + Codebreaker" exhibition (running until January in The Mansion at Bletchley Park).
Please look him up if you not aware of his incredible achievements. It will quickly become apparent why he is one of my absolute heroes.
I keep my eyes peeled for a reasonably priced P4, for now the closest I have is this very early calculator.