Free software to diagnose via computer car problems for 1996 Mazda Protege? OBD codes, etc

Is there any free software out there that I could download or pay a small price to diagnose car problems for 1996 Mazda Protege?

Thankyou in advance!

I used the “Torque” app on an Android phone with a cheap OBD dongle from Amazon when I needed to read codes.

You can also get the codes read for free at a car parts store. Is that what you need?

Here’s a list of inexpensive devices depending on what you want to use to comunicate with the vehicle. http://www.dinodirect.com/obd2-code-scanner-f-obd-6051Grid/?cur=usd&affid=3820&daf=yes&gclid=CJHVk6nWprECFUYCQAodKjgA2w

Tester