All depends on what you want to accomplish.

IP is not what I would call a lightweight protocol. Anyhow, if you want to do that you'll have to start learning about the IP protocol. Check one of the online projects on this site. ( http://www.8052.com/tcpip ).

This being said, I don't think you will be able to link your P89C52RD2 straight into the internet. Remember, the internet is BIG and not everybody on the internet has good intentions...so security will be an issue.

regards

Patrick