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Hacking a BIOS to run an AMD CPU on an old Dell computer

Posted: Mon Jun 27, 2005 4:19 pm
by krick
I have an old Dell Optiplex GXL 5133 computer.

Phoenix Rom BIOS Plus Version 1.10 A20

I would like to do an AMD K6 400 powerleap upgrade on it but the DELL BIOS has a check that prevents the computer from booting with a non-Intel CPU. I'm not sure how the check is done.

Anyway, this seems like it should be a simple modification. I'm just new to this sort of thing and need a little help getting started.

Here's a link to the BIOS file...

http://3feetunder.com/files/dell_gx_a20.zip

Inside the zip file is the EXE bios installer.

I believe the BIOS installer is compressed with an exe compressor.

Here's the unpacked BIOS installer...

http://3feetunder.com/files/dell_gx_a20_unpacked.zip

For the curious, I used UN-PACK 2.2 to figure out what it was packed
with (LZEXE) and I used X-TRACT v1.51 to unpack it.

Any help with this endeavor will be greatly appreciated.

Thanks.
Krick

Posted: Tue Jun 28, 2005 7:44 pm
by Borg Number One
To unpack to plain BIOS file from the executable just enter:

GX_A20 -writeromfile
or:
GX_A20 -writehexfile


After this, you can try everything you want with the BIOS file, :D
because there is no public tool to modify DELL BIOS files.


Well, you can try to ask Anton
anton.borisov{}gmail.com

(Replace "{}" with "@")

Posted: Thu Jun 30, 2005 6:55 am
by krick
Any idea what you'd use to decompile it once it's extracted from the installer?

Posted: Thu Jun 30, 2005 7:59 am
by Borg Number One
Hi.

As I already wrote, you can ask Anton to get more information about DELL BIOS compression and module decompression utilites.