An anonymous reader quotes a report from BBC: A man has finished building an enormous computer in the sitting room of his bungalow in Cambridge. James Newman started work on the "Megaprocessor," which is 33ft (10m) wide and 6ft (2m) high, in 2012. It does the job of a chip-sized microprocessor and Mr Newman has spent $53,000 creating it. It contains 40,000 transistors, 10,000 LED lights and it weighs around half a ton (500kg). So far, he has used it to play the classic video game Tetris. Mr Newman, a digital electronics engineer, started the project because he was learning about transistors and wanted to visualize how a microprocessor worked. The components all light up as the huge device carries out a task. Mr Newman hopes the Megaprocessor will be used as an educational tool and is planning a series of open days at his home over the summer. You can watch a video demonstration of the monstrosity here.