A long overdue trip to Bletchley Park to see the ‘Colossus’ digital computer – containing 1500 triodes, pentodes and thyratron tubes. It was an utterly incredible engineering achievement for it’s time, to design and build this machine back in the 1940s to help decipher German radio messages during WWII and also a staggering achievement by the late Tony Sale to rebuild this replica of one of the original Colossi machines from just a few black and white pictures, some scribbled notes and old telephone exchange parts. When we visited the machine was fully powered up – the 8KW power dissipation plus a hot and humid August afternoon made it uncomfortably hot inside the hut where Colossus is situated. More info can be found on the Bletchley Park website. A great day out!