The Compaq HNE-300 is a 10/100 ethernet CardBus adapter.
It is based on the 8139c chipset.
Donald Becker's 8139 driver supports it. From reading
his driver, I inferred that only table entries were
needed to make the 8139too driver support this card.
I have attached a patch that works for me under Red Hat
Linux 9 (DRV_VERSION is defined to be 0.9.26).