Running on an old IBM P100, 80MB RAM, 3c509 ISA NIC. The installer didn't probe for the NIC at all, leading to no network setup. Running "modprobe 3c509" post-install got the NIC driver working.
Additional note - this was during a Custom install.
The installer does no ISA card probing. If you enter linux expert at the boot prompt then you should be prompted for ISA type cards.