Hey Elmbeatz,
I read on another post that you were trying to upgrade a Rev. 0 board to make it Mac Compatible, did you finally get it to work? Where did you get the parts from? How hard is it to install? I have always wanted to own a EII, but have not found the right one yet. I am trying to avoid any issues of having to update the boards so that I can use it with my Mac SE/30.
Thanks
A forum member gave his self-made prototype rs422-board to me (it worked with his EII). But - it's not just putting the board into the EII. It's much much more work, and if you're not an expert in soldering and electronics and such, do NOT try to upgrade yourself, even if you have the board. There are lot of kludges to do, you can read about it in the service manual.... PAIN!
GET A REV 1, which is VERIFIED to be connectable to a mac (best would be to test it before buying).
Good luck!