[TenTec] Orion #565 I/O question

[Mike K9UW]

I'm about to order a RigExpert Plus digital mode interface for my Orion 1 and I need some advice.  

The manufacturer offers two interface cables for the Orion - one with 5 pins and the other with 8.  The dongle supplied by TenTec is a 5 pin, I 
believe, but lacks a connection for FSK.   Since I'd like to use FSK, it seems logical to request the 8 pin connector.

I'm recalling something about the 8 pin  I/O connector being "non-standard" on the Orion 1, however.  My middle-aged brain may be 
manufacturing this memory, but it is strong enough to give me pause.....

Can anyone shed light on which cable I want?

73, de Mike, K9UW
Amherst, WI