Code Reader for 91gsx? ? ? ? ?

[gsgoingT]

what type of code reader do I need for my 91gsx and where can I get one?

 

[92AWDHX40]

Palm pilot, did you look yet?

 

[NOSLO2PT0]

ECU Code Checking

 

[gsgoingT]

thanks a lot I appreciate your help, I will try electric buzzer from RadioShack first, but if you have tried this yourself do you still have to turn the key to " on off on off on" engine not running, or can you just turn the key to on possition once engine not running, does it matter? I just read some articles on how to use the code reader and it said to turn the ignition key to "on off on off on" engine not running at the on position,just for lights to come on, and then start the code read.