Design your own 20MHz Z80 microsystem.. MTX PLUS !!

[1024MAK]

I'm planning (or maybe that should be thinking about) building a simple Z80 based system.
It would not be compatible with a MTX though.
It would have SRAM, EPROM (or flash ROM), a serial port (using a Zilog serial chip), it would use a 4 line LCD as a display.
No plans for any modern interfaces.

Alas, due to having my fingers in too many pies plus real live taking up my time (work, house, DIY etc), I have got most of the parts, but have not got any further with the design.

If there was another Z80 based design, I would also be interested in that as well. I know more about hardware than Z80 assembly language (but am learning it).

Mark