The mid-80's Prelude's were a nice bike--you done good with your $10.

Are there any stickers still on the bike? If it one of them says Columbus "Tenex" tubing your bike was probably put together in Greenville, Mississippi. But your "French" parts don't seem to match-up with what I know about those bikes.

People love pictures here. And even better if you can find your serial number on the underside of the bottom bracket shell and the 4-letter date code on the Schwinn headbadge, wiser folks than me can tell you more about your bike.

You might be able to discover a bit more on your own in this old thread:

http://www.bikeforums.net/showthread...ighlight=Tenex

Enjoy your bike.