You can buy a box of ten RP2040 microprocessors for £9. You just need a couple of minutes to visit the Pimoroni or The Pi Hut website and enter your credit card details. Depending on your location, it can take a day or two for the delivery to arrive. It’s easy. Too easy for Panos Papazoglou! He’s made a fully functional microprocessor out of discrete bits of hardware. The registers that would normally be etched at microscopic level into silicon are here replaced with Arduinos, with added displays so the user can see what’s going on at any given time in any part of the device. It’s brilliantly geeky, and a superb way of visualising what’s going on inside a processor for anyone who’s looked at a chip and wondered what’s going on in there.