I know when you check the A/B port on your OBD1 you will get code 12 three times then your problem codes then back to code 12 again then back to your problem codes...endless cycle.
Ok when you do not have any problem codes you will still cycle 3 times code 12 but after the first 3 times of code 12 cycling will code 12 keep cycling over and over or is the OBD1 system set up to stop cycling code 12 after the first 3 times if there is no problem codes?

I always thought it was code 12, and then your actual codes, then repeated from code 12. I could be wrong though.