Turquoise Miyata 215st touring bike, 1987. I put Gatorskin tires on it, which should make it distinctive. The pictures I took of the serial number are hard to make out, but it's close to 098990.
Sadly, I don't have pictures of the bike, but it looks like this one:
http://www.bikeforums.net/classic-vintage/537864-after-photos-miyata-215st.html