reading codes--need help

I have an early model (apparently) 95 lumina sedan 3.1 v6. I have a few problems with this car (see other thread) but a big problem is an intermittent service engine light. I purchased a scan tool to read the OBDII codes but I have since learned that:

A. I may not have the OBDII system.
B. I do have an ALDL connector on my car.
C. the "B" pin is not included in the connector in my car.

My question to you is " How in the &^*%&$% do I read these codes?:banghead: :banghead: :banghead:

Many 1994 and 1995 (and some 1993) have the interim PCM systems which are not truly OBD-II compliant (from a communication protocol perspective), but have most of the functionality of an OBD-II system. The systems usually cannot display trouble codes by simply grounding a data request terminal. A compatible scanner or software and PC must be used to retrieve data from the serial data terminal. Several brands and types of scanners are capable, such as a Vetronics Tech I or Tech II, Matco Determinator, Snap-On MT2500, OTC, and several other brands.