Z80 Single Board Computer
This is a PCB layout by Daniel Marks of Grant Searle's 9 chip CP/M computer as obtained from
You need to follow his instructions on how to flash the memory and install CP/M.
This design uses a 28C256 (32k X 8 EEPROM) rather than the original 27128 (16 x 8 EPROM). JP6 needs to be set to the 16K setting, and only the first 16K of the EEPROM needs to be programmed.
I have added a 8255A peripheral interface and a SPI serial peripheral interface port. I plan on modifying the SD card driver to use the faster hardware on this board, using the SD card loader here:
The SPI peripheral will hopefully allow other hardware to be easily added such as an ethernet interface (Wiznet or enc28j60) for TCP/IP, a SPI LCD for display, etc. JP2 selects the clockspeed of the SPI, either 1/2 of 7.3278 MHz (slow clock) or 16 MHz (fast clock).