Oops... I meant .833" (aka 21.1mm), not .883". Apparently it was used for a while by Schwinn, Windsor, and a few other brands.

I don't have pics handy, but the bike looks very similar to the one in this thread: http://www.bikeforums.net/showthread.php?t=535818

Now that I'm searching on the right number, I found this thread, where someone claims that steer tubes for .833" stems have a 1" O.D., just with a thicker wall: http://www.bikeforums.net/showthread.php?t=485638

So I'm probably all set.