I too am using the MagCard code. I'm almost to the end of my project. I'm using a standard card reader (not serial), I2C memory to store account numbers, and RS-485 interface.

The only difference in my project is I'm stripping out only the account data and storing it. For security reasons I'm not collecting the balance of the information. (expiration date, pin hash)

I'm with Melanie in that you should start writing some code and experiment a little. I have modified her code very little and her code worked right away.