This mini project was a good opportunity for me to practice my soldering skills, as well as get my hands on a Spectrum 128K clone that I could use for various projects. I have enjoyed reading Chris Smith’s excellent articles on reverse engineering the ZX Spectrum ULA. The Harlequin is the physical embodiment of his work. The board comes in two variants; a 48K version (currently on revision G), and a 128K version (on revision …