Some more info though:
how large were the characters on screen? Were they pretty large or rather small like in Ultima? Also, did you see the entire screen or only half of it, again like in Ultima? And what age did the game have? Fate of Atlantis points to about 1993-1994 but it may be older.
There's a lot of games that are isometric and RPGs and I haven't played many of them so I can only offer some names:
Bloodstone
http://www.mobygames.com/game/dos/bl...le/screenshots
Amberstar
http://www.mobygames.com/game/dos/amberstar/screenshots
Disciples of Steel
http://www.mobygames.com/game/dos/di...el/screenshots
Daemonsgate (cool game this)
http://www.mobygames.com/game/dos/da...te/screenshots
Knights of Legend
http://www.mobygames.com/game/dos/kn...nd/screenshots
Prophecy
http://www.mobygames.com/game/dos/pr...on/screenshots
Times of Lore
http://www.mobygames.com/game/dos/ti...re/screenshots
Vampyr
http://www.mobygames.com/game/dos/va...on/screenshots
Wasteland
http://www.mobygames.com/game/dos/wasteland/screenshots
Hope it's one of these
