Building and testing a ZX Nucleon 512KB ver 3B from CSS Electronics

DIY ZX Nucleon 512KB ver 3B. This is the Czech clone of the Russian Pentagon microcomputer - itself a powerful clone of Sinclair ZX Spectrum 128 CPU: Z80A RAM: 512KB Graphics: 256x192, 384x304, 512x192 monochrome. No attribute clash Keyboard: 40 rubber keys Sound: AY-3-8910A The chip tester: Demoscene Demo: “Across The Edge“ Original Publisher: deMarche (Russia) Music track: Within Us by Epic Spectrum Source: Background Music for Videos (Free)