Geo Prizm 1993 code reader

unfortunately their is no code reader for this vehicle that I'm aware of. I gave my repair manual away when I sold my GEO, but all of the terminals on the diagnostic port are to perform a certian function, like turning on the fuel pump, engaging the AC compressor, hooking up a tach... Not for retrieveing diagnostic codes.

??
I have a 1993 Geo Prizm 1.8L 4 door. 150K miles. Auto transmission. 2WD. I need a simple code reader. Unable to locate one. Can anyone help? According to EQUUS tech., their GM reader will not work.
responed
unfortunately their is no code reader for this vehicle that I'm aware of. I gave my repair manual away when I sold my GEO, but all of the terminals on the diagnostic port are to perform a certain function, like turning on the fuel pump, engaging the AC compressor, hooking up a tach... Not for retrieving diagnostic codes.
My ??
I have the repair manual. With that will it help? I had to replace the starter thing (also is the cap and rotor) all one piece. Replaced plugs and wires too. It was a used from a pull part place. and I need to have it diagnostic. She has no guts now and she spits putters and is costing lots in gas. What can I do?