The Z80 Motherboard is designed to be low cost and easy to assemble, with the ultimate aim of making it a more reliable build.

It has few components and thus less soldering, and can even be assembled without the expansion sockets to further reduce the amount of soldering. Jumper options have been avoided to reduce complexity and confusion.

The motherboard contains the following:

• Z80 running at 7.3728 MHz
• 128k bytes of RAM (second 64k not easy to use, so best consider it to be 64k usable)
• 32k bytes of ROM, which can be paged out with the usual write to port 0x38
• Simple bit-bang serial port to get you started
• Four RC2014 standard bus sockets
• Simple reset button (no power on reset or reset debounce)
• LED for power and status indication
• Runs the Small Computer Monitor configuration S2, with ROM BASIC and the CP/M loader included

More details about the PCB can be found here.

Getting Started