This eBay auction seems to indicate the Outbound could be hooked up to a Plus or SE for "more power". However, I thought it was a stand-alone computer that used the Plus or SE ROM. Could this guy have it wrong or was there really such a feature? And if so, how did it work?

EDIT:

By golly I guess it does!

So my question now is how did this work? With the SE, I can imagine installing the card it speaks of, but how would it work on the Plus?