Re: [OT] Clearing a BIOS password
On Wed, 20 Nov 2002, Pigeon wrote:
> On Tue, 19 Nov 2002 13:54:10 +1000, John <johnpf@atnet.net.au> wrote:
>
> >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.
> >
>
> This lot may help you - it's all the stuff I could find in CMOS.LST
> from Ralf Brown's Interrupt List about AMI BIOSes. It's a bit old but
> probably not unusably so. Sorry for the length.
Check the system docs. The Acerpoer 6100 I have here has a jumper to disregard
the password. Some systems have jumpers you short to clear the password.
--
Cheers
John Summerfield
Please, no off-list mail at all at all. This address accepts mail only from Debian lists.
Reply to: