Most of the same readers will pull OBD-I codes as well, though I don't know how far back that system went. It's been a long time since I owned a pre-1996 car. I also don't claim to know what the standards were outside the United States -- I'm sure plenty of places still don't care a hoot about OBD stuff, though manufacturers are likely building it in by default at this point.

Cheers, John