Check engine light

I have a 94 sport, the check engine light comes on about 10 to 15 minutes into the drive. I've checked the engine and nothing seems out of the ordinary. Is there a commercial code reader that i can buy or rent? Its not a 96 so it does not have the universal plug. If so where would i plug it in to get the code. Any thoughts

You will find what you need here and a list of codes as well.
http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152800a9b7c

the MIL method ..