Was it that only the 85 could connect to a com port, but then you could connect the 85 to the 82/83? I seem to remember pleading with the one kid with an 85 (who didn't even care about games).
I chopped my TI-83 link cable in half and wired it to the parallel port, like this: http://www1.inf.tu-dresden.de/~aw4/ti85.html
and this: https://web.archive.org/web/19990117001444/http://www.geocit...
The 82 also had a com port
I don't remember if you could connect an 82 to an 85, but I do remember you could connect it to a PC as well over serial