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Re: [OT] Clearing a BIOS password



Mark L. Kahnt wrote:

Anyone remember how to clear a password on a BIOS? I've got a box from a
client that has stopped booting from CD, and this client is ready to
move to dual-booting but this is his main desktop box and it needs some
cuffing around the BIOS. The password was put on by the vendor of the
box, who then went broke three months later. I need to get Windows
working (certain key files were clobbered by yet another virus -
including explorer.exe - likely others, but I'm finding them
one-at-a-time) to at least extract some key data before re-partitioning,
and currently, for some strange reason, Windows can't see the cd-rom at
all (while 2DiskXWin does, so I know that the hardware is okay - only M$
is $crewed ;)

Yeah, it's all complicated - simply put, I need to clear the BIOS
password, and I've forgotten the normal trick (other than removing the
battery and disconnecting the power supply, and hoping the CMOS is
static RAM rather than EEPROM - which one guy I know used a number of
years back for his garage-built line of boxes.)
You can also get at the BIOS contents via port 70 (you need to write the address you want to access there) and port 71 (which you read and write data from/to).

You'll need to track down exactly what addresses you'll need to touch via the web somehow, then boot a DOS disk and use DEBUG to toggle the address which says a password is set. As I seem to recall it's a binary flag inside a byte somewhere. It's a long time since I did any of this stuff, so I cant tell you anymore details. A clever Linux hackor could probably do it as root via /proc, but I have no idea how to get there.

John P Foster
Senior Research Scientist
Golden Orb Technologies LTD



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