emulatorII-list

I'm looking for help in trouble-shooting my RS 422 Port on my EII. 
It seems that my recently aquired EII has serial #1101 which is one 
increment higher than the document that states the following in the 
techinical folder in the files section of this users group:

"Important: Emulator II's with serial numbers below approximately 
#990 (dual drive) and #460 (single drive) require an upgrade that 
converts the serial interface to RS-422 to work with Sound Designer.

Some Emulator II's with serial numbers from approximately 950 to 1100 
require a modification to work with Sound Designer."

 The big word is "approximately." All of the EPROMS check out with 
the correct number on their label but I still can't get the SD for 
EII program to access the EII. Does anybody have the documentation or 
procedure to modify the RS 422 Port so I can see if in fact this EII 
needs such a retro. I checked the cable at least 5 times including 
continuity tests and it checks good.  

Any help on this issue would be appreciated.
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