You don't say which distribution you are running and that is the first important piece of information anyone will need to know.
The 3c501 is an old wired ethernet card that is at the top of the list in most linux distributions configuration gui. If it is shown it just means that Linux is not recognising your wireless card and you have more work to do.
Run the command:
from a command prompt and post back the results where they relate to your wireless card.
I'm assuming there that you have an internal pci card. If you have a USB wireless adapter use the command:
Post back the answers to those questions and either I, or someone with experience of your version of Linux, may be able to help.