> David Wilson mentioned that the board didn't run OS-9 L2. Not to
say that you
couldn't do a port of NitrOS9 to it should you care to design one.
Indeed.
Either you make the board a functional emulation of the Mill card
allowing you to run any (and all) existing software designed for the
Mill OR you make a generic 6809 card with as much hardware support
(more RAM, MMU etc etc) and then write your own custom drivers to
allow OS9 Level 2 to run on it.
The former is a logical first step, the latter an advanced project
that is best looked at after getting the Mill emulation working.
Just like the Microsoft CP/M card vs PCPI card designs, the Mill was
designed to leverage the m/b RAM and I/O but now you can get more RAM
in a single SRAM chip than a standard 128K IIe meaning a separate
computer utilizing the Apple II for power and I/O makes more sense
(that way the 6809 is not limited to 1MHz).