Can I connect

I was wondering if I can connect to the internet via a cable modem and then broacast that signal with a airport base station original. My computer is an orignal G5 and has no airport card and I can't seem to stay connected to the internet once I try and make the connection to the base station in order to allow my other roomates who have wireless to access the connection

buy a router and plug your computer into the the router using the ethernet port and let your roommates use the wireless. or you can buy usb wireless adapters to connect the wireless if you don't want any wires?