ZX8081 ZX81 ZX80 Wilco2009 rev1.1 PCB from LP74S00 on Tindie
TS1000/ZX81 Tactile Keyboard,ZX81 Part 2 – Upgrading the on board memory from 1K to 16K,ZX8081 ZX81 ZX80 Wilco2009 rev1.1 PCB from LP74S00 on Tindie,Easy add-on Projects for Spectrum ZX81 & ACE (Redux): Part 2 - ZX81 Keyboard Adventure