Here is the Schematic for my Z80 Playground v1.1 Single-Board-Computer. It has got a Z80 processor, 32K EEPROM, 64K RAM, a 16550 Uart and USB Drive for mass-storage. Click the “Download” button to get it as a PDF.
Here’s an overview of my Z80 Playground single-board-computer. This is v1.1, dating from June 2020. I have now got it working well!