upgrading flash on 3c905b

Hope this isn't a frequently asked question.  Is it
easy to upgrade the PXE bootstrap on the 3c905b
from v0.99j to something newer (like PXE v2.x)?
I recall using a utility named pxeflash.exe for a
Dell Optiplex (with a 3c905c on the motherboard).
Would like to do something similar for an old
HP Vectra with a 3c905b PCI NIC installed.  Is the
PXE code entirely on the 3Com NIC, or would this
require a BIOS change?

Also, wake on LAN doesn't appear to be working on
the Vectra, even though it's enabled in the BIOS config
settings and there's a WOL cable from the NIC card
to the motherboard.  Will updating the 3c905b onboard
flash help?
     Thanks,
     Ed