i've just got a 3com fast ethernet card (3c905b-tx) and wondering if it's any good. also there seems to be a upgrade slot on the card and i'm wondering what it is. it seems to be a mem upgrade or something.
that "slot" you are reffering to is for a BOOT ROM. Installing a BOOT ROM onto that NIC will allow you to boot a driveless machine, over a network. AKA as a dummy terminal.