1993 Mazda MX3 Clearing error codes

My MX-3 has had the Check engine light on for the last three years, engine runs fine, no idle problems or smoke of any type, in short no problems to report.

I will have to sell the car soon and I'd like to know the error code to fix the problem or clear the error codes. I know it got an ODB1 port next to the battery. What pins do I have to jump to read the flashes. If its like the MX-6 first flashes should be the 10 digits followed by the single digits.

Next do you have a code chart?

Finally how do I clear the codes?

Thanks all.