Colossus was the world's first electronic, digital, programmable computer. Colossus and its successors were used by British code breakers to help read encrypted German messages during World War II. 2,500 Vacuum tubes were used to perform the calculations. Colossus didn't have an electronic memory, but instead relied on long strips of paper tape with holes punched in it that would blast through the machine at nearly 50 miles an hour. The computer itself could operate even faster than this, but the tape would disintegrate. The giant machine could crack German codes in hours rather than the weeks needed by manual decryption.
In order to raise the funds needed for for a new gallery in which to show off this modern marvel of yesteryear, the UK’s National Museum of Computing is allowing generous souls to sponsor the various valves of Colossus by buying pixels on their website at £10 a section. You can help out at ColossusOnline.org.