Try running "lsmod" (or "/sbin/lsmod") in a terminal and that will tell you which kernel modules (i.e. drivers) are loaded. Do you see 3c501 in the list? If not, try "modprobe 3c501". Does that return any errors?
Also, it's advisable not to use Red Hat 9 as it's seriously out of date now and no longer supported by Red Hat. You'd be wise to consider installing a newer distro instead. Out of curiosity, why did you choose Red Hat 9?!