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 £40,000 ($53,000) creating it.
It contains 40,000 transistors, 10,000 LED lights and it weighs around half a tonne (500kg). So far, he has used it to play the classic video game Tetris.