PCF1306 (ZX8401, Amstrad 40058) replacement for ZX Spectrum - Share Project - PCBWay,SparkFun ProDriver and Mini Stepper Motor Driver Hookup Guide - SparkFun Learn,ZX-81 memory mod, case & keyboard restoration, test-drive (Pimp My Eight, episode 4, part 3) - YouTube,ZX-81 composite video mod and various upgrades (Pimp My Eight, episode 4, part 2),ZX Spectrum 48k Repair: A Journey Inside the Unit,