EmulatorII-list

Hi,

I'm new to this group and I just bought a damaged EII on ebay.
I managed to fix it by cleaning the head of the 5.25" floppy with q-
tips and ethyl alcohol. Everything works fine now and I can work with 
the EII. What a great machine!
 
But I still have some(maybe) newbie questions.
While opening the EII for cleaning I discovered the "memory option 
board". I wonder what it does. Is it a RAM expansion to 1MB? And if so 
how do I access the second bank?

The main issue I have is that my EII only provides the RS232 interface.
Since I want to connect the EII to a Mac I need to fix that.
Does anyone out there have a PCB layout for modding the EII to accept 
RS422? A scan (top and buttom) of the adapter board would also be great!
It seems to be a very simple circuitry and I think its easy to built.

Thanks in advance!

wintermute