On Tue, 5 May 1998, Ken Nakata wrote:

> Second, you have to find the address where the MAC address is stored
> in the ROM.  If the card is in the slot <n>, the NuBus base address
> for the card is 0xfn000000.  You may be able to use MacsBug's search
> feature to find the offset from the base address.  Note, however, that
> the 6 byte long MAC address may not be stored in consequtive memory.
> I've seen an Ethernet card on which the MAC address for the card is
> stored in every other byte.  It may even be stored in every fourth
> byte.

Actually, depending on the "bytelanes" field of the card's Declaration
ROM, the bytes of the MAC address could be in almost any order.  Common 
cards use every fourth byte, sometimes with the low 2 address bits set,
sometimes with them clear.  Other cards have 4-byte wide transfers, and
use every address.  Still others have 2-byte transfers...  Still others
use one-byte transfers with only the odd or even addresses...  NuBus is
a real PITA.

You can use the Slots program (available on Apple's Web site) to locate
the board resource that contains the MAC address.

> As I wrote before, some of us might be able to help you when you get
> stuck, if you give us enough information.

Yep - if you get the Slots program, I'd be happy to walk you through the
steps required to find the MAC address resource.


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