3 (or 4 or 5)-chips Z80 SBC

I have started working on a Z80 board that would use only 3 parts (Z80, RAM, Glue logic+SIO). The Glue is done via a PSoC4 from a Cypress CY8CKIT-049-42xx (<5 euros…) – Currently the Flash chip is not used, and only 64KB from the RAM (128K) is used. Z80 is...