Burn an v74 ROM

Hallo,
i want to burn for my Nextstation Turbo an v74 ROM so i can connect an ADB keyboard and mice.
The file i have already downloaded.
But i think i must edit the ROM to put the original Macadress from the Ethernet Card in it.
Is this correct or i am wrong?

Anybody who has an manual for me? Where can i find the Macadress in the Rom File. What is the OFFset?

I hope anybody can help me.

Thanks

If you don't have any software which is locked to the mac address then you should be fine using the mac address from the existing ROM image. I have a machine running like this with no issues. If you do have any software that is locked to the mac address then I only know of this software fix:

https://groups.google.com/forum/#!searchin/comp.sys.next.hardware/mac$20address/comp.sys.next.hardware/_em2i-FA3z8/9ZTx7v3jiUUJ

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Brian

Thank you Brian.
I thought that it is necessary to burn the address in the ROM.
But i don't have any software which is locked to the macadress so i can burn the ROM directly without modification.

Thank you very much.

Maik

For those who want to burn a v74 ROM for turbo black hardware, you can use the image we have in the archives (http://www.nextcomputers.org/NeXTfiles/Software/ROM_Files/68040_Turbo_Chipset/) as-is.  Just be aware that you may have issues if you connect two machines on your home network with the same ROM image (MAC address).

If you want to burn your own v74 ROM and change the MAC address, there are instructions for calculating the checksum in this thread:

https://www.nextcomputers.org/forums/index.php?topic=11 (https://www.nextcomputers.org/forums/index.php?topic=11)

I first did it years ago and it's pretty straightforward to do.  I've since used the XVI32 (http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm) hex editor because it will also do the checksum calculation, as will many other hex editors.

The MAC address consists of 12 hexadecimal numbers.  The first six digits 00-00-0F were assigned to NeXT back in the day, so you should keep those the same.  You can see the OUI (https://en.wikipedia.org/wiki/Organizationally_unique_identifier) numbers assigned to NeXT on this list (http://standards-oui.ieee.org/oui/oui.txt).  The last six digits can be any hexadecimal numbers you want.

As for the 32-pin EPROMs, 27C010A (http://www.futurlec.com/Memory/27C010-120pr.shtml) is the part number I have on hand and 200ns and faster EPROMs seem to work fine.

So the steps to change the MAC address are:

1.    Load our v74 ROM image into a hex editor.
2.    Change the last six digits of the MAC address to your desired numbers.
3.    Calculate the checksum per the forum thread mentioned above.
4.    Change the checksum (circled in pink by Andreas in the checksum thread).
5.    Save the ROM image and burn it to a new EPROM.

If you have any questions please feel free to ask.