My TT has a GEsoft RAM board that takes SIMMs (about 18 of them!!), but I think Atari may have supplied some machines with a SIMM adaptor? Because the RAM bus in the TT is proprietory, like with the Falcon. I also know there were ST RAM cards that took SIMMs like the STE, although my 4MB ST RAM card has embedded chips.
Did I read somewhere about an 8MB ST RAM card or am I being unusually crazy? That would be nice for with my SLM605...